FAO Fisheries Synopsis No. 125, Volume 11
FIR/S125 Vol. 11
FAO SPECIES CATALOGUE
VOL. 11. SEA TURTLES OF THE WORLD
AN ANNOTATED AND ILLUSTRATED CATALOGUE
OF SEA TURTLE SPECIES KNOWN TO DATE
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
FAQ Fisheries Synopsis No 125. Volume 11
FIR/S 125 Vol. 11
FAO
SPECIES
VOL. 11
CATALOGUE
SEA TURTLES OF THE WORLD
An Annotated and Illustrated Catalogue
o f Sea Turtle Species Known to Date
prepared by
René M arquez M.
Instituto N acional de la Pesca
Centro de Inve stiga ció n Pesquera
A p a rta d o Postal 591
Manzanillo, Coi. México 28200
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
Rome, 1990
T he d e s ig n a tio n s e m p lo y e d and th e p re s e n ta tio n o f
m aterial in this publication do not im ply the expression
o f any opinion w h a tso eve r on the part o f the Food and
A g r ic u ltu r e O r g a n iz a tio n o f th e U n ite d N a tio n s
c o n c e rn in g th e le g a l s ta tu s o f a n y c o u n try , te rrito ry ,
city or area or o f its a u th o ritie s, or co n ce rn in g the
delim itation o f its frontiers or boundaries.
A ll rig h ts rese rve d . No pa rt o f th is p u b lica tio n m ay
fo rm o r by a n y m e a n s, e le c tro n ic , m e c h a n ic a l,
co p yrig h t owner. A p p lica tio n s fo r such perm ission,
s h o u ld be a d d re sse d to the D ire ctor, P u b lic a tio n s
Via delle Terme di Caracalla, 00100 Rome, Italy.
be rep ro d u ce d , sto re d in a re trie va l syste m , o r tra n s m itte d , in any
p h o to c o p y in g o r o th e rw is e , w ith o u t th e p rio r p e rm is s io n o f th e
with a statem ent o f the purpose and exte nt o f the reproduction,
D ivisio n , Food and A g ric u ltu re O rg a n iza tio n o f the U nited N ations,
© FAO R om e 1990
PREPARATION OF THIS DOCUMENT
T heir high com m ercial value and traditional role as a basic protein source for many riparian peoples in tropical and
subtropical areas place sea turtles am ong the m arine resources groups o f m ajor interest to fisheries. On the other
hand, they also have become part o f the rapidly increasing group o f marine anim als that are seriously threatened by
over-exploitation and other m an-related disturbances.
The present catalogue is an attem pt to present a global synthesis o f the inform ation on sea turtle species scattered in
many specialized publication series and th u s facilitate the w ork o f fishery officers and e n vironm entalists tow ards
m anagem ent, farm ing and protection o f these fascinating and delicate anim als.
The author has collaborated with FAO for m any years in the preparation o f species identification sheets for sea turtles
from various marine fishing areas, e.g. the W estern Central Atlantic, the Eastern Central Atlantic, the W estern Indian
O cean and the M ed ite rra n e a n /B la ck Seas. For the past 20 years, he has been a ctively engaged in research
program m es, as w ell a s in m anagem ent, protection and farm ing activities, both in the fram ew ork o f th lUCNeand of
the Instituto
National de la Pesca o f Mexico. He is currently the C oordinator o f the M exican National Research
Program me on Sea Turtles o f the Secretaria de Pesca o f México, m em ber o f the Marine Turtle Specialist Group o f the
IUCN and President o f the Ad Hoc Com mission for the Investigation o f the Sea Turtles o f the Am erican Pacific.
Technical Editors:
W. Fischer, W. Schneider and Nadia Scialabba, Fishery R esources and Environm ent Division, FAO
Illustrators:
P.
Page composition:
Lastrico, FAO, Rome and R. M árquez M., INP, Mexico
M. K autenberger-Longo, FAO, Rome
M árquez M., R.
FAO species catalogue. V ol.11: Sea tu rtle s o f the w orld. An a nnotated and illu stra te d ca talogue o f sea tu rtle
species known to date. FAO Fisheries Synopsis No. 125, Vol. 11. Rome, FAO. 1990. 81 p.
ABSTRACT
This is the eleventh issue in the FAO series o f w orldw ide annotated and illustrated ca ta lo gu e s o f m ajor
groups o f organism s that enter m arine fisheries.
The present volum e includes 8 sea turtle species belonging
to 2 fa m ilie s and 6 g e nera. It co m p rise s an in tro d u cto ry se ctio n w ith ge n era l rem a rks on h a b itat and
fish e rie s o f the fam ilies, a glossary o f te ch nical te rm s used, an illustrated key to genera, and detailed accounts
on all species. Species a cco u nts include d raw ings, scie n tific and ve rn a cu la r nam es, inform ation on habitat,
biology and fisheries, and a d istribution map. Lists o f nom inal species in the fam ilies, a table o f species by
m ajor m arine fishing areas and colour plates follow the species accounts. The w ork is fully indexed and there
is ample reference to pertinent literature.
Distribution
A u th o r
FAO F is h e rie s D e p a rtm e n t
FAO Regional Fisheries O fficers
R e g ional F isheries C ouncils
and C o m m is s io n s
Selector Global Species Catalogues
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iV
TABLE OF CONTENTS
Code
Page
1.
IN T R O D U C T IO N ................................................................................................................................................................................
1.1
1.2
1.3
Plan o f the C a t a lo g u e ........................................................................................................................................................................... 1
G eneral Rem arks on Sea Turtles ................................................................................................................................................
2
Illustrated Glossary o f Technical Term s and M easurem ents ............................................................................................. 4
2.
SYSTEM ATIC CATALOGUE
2.1
2.2
Illustrated Key to Families and Genera ....................................................................................................................................... 10
Family C h e lo n iid a e ...................................................................................CHEL ........................................................................ 13
.......................................................................................................................................................
C a r e t t a ........................................................................................................ C H E L
C a re tta c a r e t t a ........................................................................................ C H E L
C h e l o n i a .....................................................................................................C H E L
C h e lo n ia a g a s s i z i i ................................................................................. C H E L
C h e lo n ia m y d a s .....................................................................................C H E L
E r e t m o c h e ly s ........................................................................................... C H E L
E re tm o c h e ly s i m b r i c a t a .................................................................... C H E L
L e p i d o c h e l y s ........................................................................................... C H E L
L e p id o c h e ly s k e m p i i ...........................................................................C H E L
L e p id o c h e ly s o l i v a c e a ........................................................................C H E L
N a t a t o r ........................................................................................................ C H E L
N a ta to r d e p r e s s u s ..................................................................................C H E L
2.3
F a m illy D e r m o c h e ly id a e .........................................................................
LIST OF SPECIES BY MAJOR FISHING AREAS
4.
B IB L IO G R A P H Y
5.
IN D E X OF S C IE N T IF IC A N D V E R N A C U L A R N A M E S
10
C a r ................................................................13
C a r 1 ......................................................... 14
C h e l............................................................... 21
C h e l2 ...................................................... 21
Chel 1 .........................................................25
E r e t .........................................................
30
E ret 1 ........................................................... 31
L e p ............................................................... 38
Lep 1 ............................................................ 38
Lep 2 ............................................................43
Nat ............................................................... 49
Nat 1 ............................................................. 49
DERMO
..................................................... 53
D e r m o c h e ly s ............................................................................................... D E R M O D erm o .................................................
D e rm o c h e ly s c o ria c e a ........................................................................D E R M O D erm o 1 ...............................................
3.
1
53
53
.............................................................................................................................. 59
...........................................................................................................................................................................
61
......................................................................................................75
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1
1. INTRODUCTION
A lthough sea turtle conservation program m es have been encouraged by the recent discovery o f im portant new nesting
beaches, the future o f sea turtles is still threatened by the decline o f th e ir natural populations, especially in nesting areas.
Research and conservation a ctivities on sea turtles are increasing, but there are still m any gaps in our knowledge o f the
life history o f these animals.
This catalogue provides a brief description o f the w o rld ’s eight sea turtle species, as well as up-to-date inform ation on the
state o f the va riou s populations presently or historically exploited by man. It also includes g u id elines for species
identification, diagnoses o f fam ilies, genera and species, and notes on geographical distribution, habitat, and biology of
each species. A good understanding o f the biology o f sea turtles is essential for th e ir m anagem ent and protection.
Since the present docum ent is not intended as a prim arily ta xo no m ic w o rk on the group, the com plex problem o f
su bspecies has not been treated in detail. Furtherm ore, the com pilation o f inform ation for each species is far from
com plete and hence, it is advisable to consult other recent publications on this group, such as, for exam ple, Björndal, K.E.
(ed.), 1981: Biology and C onservation o f Sea Turtles. Proceedings o f the W orld C onference on Sea Turtle Conservation.
W ashington, D.C., 20-26 N ovem ber 1979, and Bacon, P. e t al. 1984: The Proceedings o f the W estern A tla n tic Turtle
Sym posium, W AYS-I, San Jose, C .R., 17-22 July 1983 (Spanish edition 1987). and W ATS-II, M ayaquez, Puerto Rica, 12-16
O c to b e r , 1 9 8 7 .
Finally, it is obvious that not all existing inform ation on sea turtles w as available to the author. Catch statistics by species
were usually difficult to evaluate or were available only in local records; no statistics are recorded on the bycatch o f sea
turtles in shrim p fisheries, and in many places, catch figures are concealed or m islabelled. The reader is hereby kindly
requested to notify the editors and the author o f possible errors and om issions that should be corrected in eventual future
editions o f the catalogue.
1.1 Plan of the Catalogue
F ollow ing the general introductory section and the illustrated keys, the inform ation on fam ilies, genera and sp ecies is
presented in alphabetical order. The species accounts are arranged as follows:
(1)
(2)
Scientific nam e : Reference is given to the original description o f the species.
S yn on ym y
S ynonym s and d iffe re n t nam e co m b in a tio n s are listed
nom enclatorial problem s are discussed under “ Rem arks” (see paragraph 11).
(m isid e n tifica tio n s
and
o ther
(3)
FAO Species Nam es : English, French and Spanish nam es for each species were selected on the basis o f the
follow ing criteria: (i) each name must apply to one species only, in a worldw ide context; (¡i) the name should
not lead to confusion w ith o ther species. W herever possible, the d enom inations selected were based on
ve rn a cu la r nam es (or parts o f nam es) already in existence w ithin the areas w here the species occur. FAO
species nam es are not intended to replace local names, but they are considered necessary to overcom e the
considerable confusion caused by the use o f a single name for many different species, or several nam es for the
same species.
(4)
Diagnostic Features : Distinctive characters o f the species as an aid for ¡dentification. S pecies identifications
should be attem pted only after consultation o f the illustrated key to fam ilies and genera.
(5)
G eog rap hical D istribu tio n : The entire g e ographic range o f the species, including areas o f seasonal
occurrence, is given in the text and shown on a sm all map. In cases where only scattered records o f occurrence
are available, interrogation m arks are used to indicate areas o f suspected distribution.
(6)
Habitat and B iology : The typical habitat and biological inform ation, such as details o f m igrations, breeding,
egg-laying behaviour, season and areas, and food and feeding grounds.
(7)
Size : The m axim um total carapace straight-line length and weight. Also, average size and w eight o f eggs
and hatchlings. Size at first maturity, and average size recorded during the nesting period.
(8)
Interest to Fisheries : An account o f the areas w here the species is captured and o f its fishery. Its im portance is
either qualitatively estim ated or figures o f annual landings are provided. Data on utilization are also given
w here available. Here too, the q u ality and qu a ntity o f the inform ation available vary co n siderably w ith
species and countries. If species are considered threatened or endangered, and if they are the object o f an
enhancem ent program m e, or protection laws, this is mentioned under “ Rem arks” (see paragraph 11).
(9)
Local Species Nam es : These are the nam es used locally for the various species. The present com pilation is
necessarily incom plete, since only a fraction o f the local nam es used thro u g h o u t the w orld is a ctually
published Usually, local nam es are available only for sp ecies supporting traditional fisheries. A p a rt from
2
possible om issions due to lim itations o f available literature, some o f the d enom inations included may be
som ew hat artificial (i.e. through transliterations o f indigenous w ords into English or vice versa). Each local
species denom ination is preceded by the name o f the country concerned (in capital letters) and, w here
necessary, by the geographical specification (in low er case). W h e n e ver possible, the language o f the
transcribed vernacular name is added in parenthesis. W hen more than one name is used w ithin a country, the
official name, if available, is underlined.
(10 )
Literature : This includes references to im portant publications relevant to the species, the em phasis being on
biology, conservation, and fisheries. These references are included in the bibliography at the end o f the
c a ta lo g u e .
(11 )
Rem arks : Im portant inform ation concerning the species not fitting in any o f the previous paragraphs is given
here.
1.2 General Remarks on Sea Turtles
Sea turtles were com m on in the Cretaceous, 130 m illion years ago, and their fossil record extends back at least 200 m illion
years. They lived to g eth e r with dinosaurs, and have survived the giant P le sio sa u ru s and the Ich th yosa u ru s. All presentday genera and species originated in the period from the early Eocene to the Pleistocene, between 60 and 10 million years
ago. T ogether w ith the m arine snakes and iguanas, they are the only surviving sea-w ater-adapted reptiles. T heir
distribution is m ostly tropical and subtropical and they depend on the land only during the reproduction period (except
some viviparous sea snakes).
In spite o f th e ir circum tropical distribution, sea turtles are represented by species that differ w idely in their seasonal cycles,
geographical ranges and behaviour. There are also considerable differences am ong populations o f the same species.
All sea turtles have a high com m ercial value. T heir im portance varies am ong countries and also, locally w ithin countries.
In some areas, they constitute a valuable protein source, in others they are only used as a delicacy. In certain countries,
sea tu rtle s have been the object o f ancient ritual practices, or they are venerated as sacred anim als. Since the Second
W orld W ar, com m ercialization o f sea tu rtle s has increased considerably. A s a result o f this, the form erly num erous
colonies have been very rapidly depleted and some o f them nearly extinguished. Nowadays, additional problem s such as
pollution, beach invasion, poaching, entanglem ent o f tu rtle s in set-nets, or th e ir drow ning in traw l-fishing, are further
endangering these species, and it has becom e evident that the rem aining sea turtle populations are seriously threatened
if these dangers cannot be reduced.
The sea turtle catch is prim arily directed to the sale o f fresh m eat for human consum ption. However, egg-harvesting is
also im portant to riparian people o f m any countries. Leather made from turtle skin is a relatively new product introduced
in the international m arket about 20 years ago. Tortoise-shell or “C arey” w a s com m on for ornam ental use in Europe
during the M iddle Ages, and even e arlier in Oriental countries (e.g. Japan), w here it had and still has a deeper cultural
value, being used during wedding cerem onies in the bride’s costume, and as carved pins in the hair. Turtle oil has multiple
uses, principally as a basic ingredient o f certain cosm etic cream s, or as m edicine for pulm onary diseases. The com m ercial
value o f sea turtles varies strongly from one species to another. The green sea tu rtle s (C helonia) are pursued for their
m eat; the hawksbill (E retm o ch elys) for its shiny tortoise-shell; the Ridley (L ep ido chelys) for its excellent leather; the
leatherback (D erm och elys) for its large yield o f oil; the loggerhead (Caretta) is the least profitable o f these species. The
eggs o f m ost sp ecies are harvested w h e re ve r found, usually irrespective o f official perm its. All species, except the
leatherback, are used for the production o f “ca lip e e ” and “calipash” w hich are strips o f ca rtilaginous tissue taken from
the rim s o f the carapace and plastron and betw een the bone plates o f the plastron. T his product is used for the
preparation o f “turtle soup” , an expensive item in many top quality restaurants.
N ow adays, alm ost all sea tu rtle s are considered thre a te n e d or endangered by the International Union for the
Conservation o f Nature and Natural Resources (IUCN), quoted in the Red Data Book, and their com m erce is prohibited in
those countries that have signed the Convention on International Trade in Endangered Species o f W ild Fauna and Flora
(CITES).
Program m es for the recovery and e nhancem ent o f depleted pop ulatio n s are undertaken in the fram e w o rk o f a
w orldw ide action, supported by local or international w ildlife fou nd a tio n s in conjunction with va riou s governm ental
organizations. Those cam paigns include principally law enforcem ent, adoption o f fishing regulations, gear restrictions
(e g ., TED or “Trawl Efficiency D evice” or “ T u rtle Excluder D evice”), protection o f nesting areas through turtle camps,
nurseries for hatchling release, and “im p rin ting-headstarting” aim ed at the developm ent o f new nesting places and o f
the avoidance o f the strong predation to w hich sm all tu rtle s are subjected during the first ye a r o f th e ir lives. Some o f
these a ctivities are still in the experim ental phase but may becom e im portant tools for avoiding the extinction o f these
valuable animals.
Because o f the depletion o f natural populations, two additional m ethods o f augm enting sea turtle populations (especially
o f the green turtle Chelonia m ydas) have been introduced. The first m ethod, called “R anching”- involves raising sea
tu rtle s from eggs or hatchlings taken from wild stocks to a m arketable size. T his is not a closed-cycle system as it
3
continually relies on wild populations as a source for eggs or hatchlings. The second m ethod, known as "F arm ing " - relies
only initially on wild populations for eggs or hatchlings (and occasionally, later, in order to m aintain a genetic diversity, to
avoid problem s with inbreeding); it attem pts to raise these hatchlings to m aturity for breeding and developm ent o f a selfsustaining captive population. Both p ra ctice s
ap p ea r to be harm less and could be o f aid to the survival o f natural
pop ulatio n s by reducing the trade pressure on w ild stocks, but they have raised more controversy than had been
suspected at th e ir inception. The com m ercialization o f sea turtles is now under review by CITES, and trade with anim als
bred in captivity is allow ed only if the breeding sto ck is not replenished from the wild popuation and if the farm can
reliably produce a second generation o ffspring under captive conditions. A second generation is defined as that
conceived in captivity from parents that were also born in the farm.
Official catch statistics for sea tu rtle s are rather scanty and doubtless represent only a sm all fraction o f the actual capture.
The world catch o f adults reported for 1987 inthe FAO Yearbook on Fishery Statistics totalled 3 100 m etric tons, o f which
ca. 1 200 m etric to n s came from the W estern Central A tlantic (Fishing Area 31), 864 m etric tons from the Eastern Central
Pacific (Fishing Area 77), 305 m etric tons from the South East Pacific (Fishing Area 81), 258 m etric tons from the W estern
Central Pacific (Fishing Area 71), 190 m etric tons from North W est Pacific (Fishing Area 61), 153 m etric tons from the
Eastern Central A tlantic (Fishing Area 34), 50 m etric tons from the Eastern Indian Ocean (Fishing Area 57), 37 m etric tons
from the W estern Indian Ocean (Fishing Area 51), 20 m etric tons from the M editerranean (Fishing Area 37) and 10 m etric
tons from the South East A tlantic (Fishing Area 41). No statistics are reported for turtle eggs.
A c k n o w le d g e m e n ts
I wish to extend my
Anne M eylan (Florida
Fisheries Center, La
Dermochelys', Henry
genus Chelonia', and
special th a nks to the follow ing colleagues for th e ir suggestions and technical revisions o f the text:
Marine Research Institute, San Petersburg, Florida), genus Ertmochelys', Karen Eckert (Southw est
Jolla, California) and Peter Dutton (Sea W orld Research Institute, San Diego, California), genus
Hildebrand (Corpus Christi, Texas), genus Lepidochelys', John Hendrickson (Corpus Christi, Texas),
Colin Liropus (National Parks and W ildlife Service, Townsville, Australia), genus Natator.
I am m ost grateful to W. Fischer and W. S chneider (FAO) for th e ir encouragem ent and final revision and editing o f the
m anuscript. Thanks are also due to P. Lastrico (FAO) for his illustrative w ork and to M. K autenberger-Longo (FAO) for
page com position.
Thanks are extended to the sta ff o f the "Program a Nacional de Investigación de T ortugas M arinas” (Instituto Nacional de
la Pesca, Secretaria de Pesca, M exico) who provided most o f the inform ation on the sea turtles o f Mexico and to M ima
Cruz R., w ithout whose help this w ork could not have been completed.
Special thanks are due to my friend, the late Carlos Maya U., who passed away this year while conducting research on the
sea turtles o f Escobilla in Oaxaca, Mexico.
4
1.3 Illu s tra te d G lo ssary of T ech n ical Term s and M easurem ents
head width
prefrontal
scales
head lenght
precentral scute
central (neural)
scutes (C1-C5)
lateral (costal)
scutes (L1-L5)
orbita
lenght
to ta l length
preorbital
lenght sx ^
marginal
Fig. 2
Lateral view of head
postcentral (pigal, supracaudal
suprapigal) scutes
c a ra p a c e w id th
mentonian scute
intergular scute
Fig. 1
Schematic dorsal view of a sea turtle
axillary
scutes
1: guiar; 2: humeral;
3: pectoral; 4: abdominal;
5: femoral; 6: anal scutes
H
marginal
infra margina I
scutes and
pores
interanal
scute
Fig. 3
Schematic ventral view of a sea turtle
(right side: male, left side: female)
d
claw
5
neiral plates
nucal plates
cervical
vertebrae
pigal plates
vertebrae
ribs
pectoral girdle
epiplastron
xiphiplastron
entoplastron
hypoplastron
pelvic girdle
hyoplastron
Fig. 4
Schematic generalized sea turtle skeleton
Abdominal scutes - The pair o f plastral scutes in nearly
central position. They are in contact with the pectoral,
fem oral and infram arginal scutes (Fig. 3).
A lveolar - The ridges and inner grooves o f the m andibles
w here the horny beak or tom ium is im planted (Fig. 5).
edge of
upperjaw
/ T '
A x illa ry notch - Frontal cavities on each side o f the body
between the carapace and plastron, from which the fore
flip p e rs p ro je c t (F ig . 7).
axillary
notch
alveolar
groove
tomium
or beak
A rribazon (Arrival) - Spanish word used to describe the
sim ultaneous em ergence o f nesting fem ales on a sm all
stretch o f sandy beach. It extends from several hours to
several days. Also “Arribada” is used.
epiplastron
entoplastron
hyoplastron
choanae
bridge
bones
«Ni-;
Fig. 5
hypoplastron
Diagramm atic ventral view of head of an adult
Kemp's ridley
Anal scutes - The rearm ost pair o f scutes o f the plastron
(Fig. 3).
A n g u lar bone - Postventral elem ent form ing the lateral
surface in each ram us o f the lower mandible (Fig. 6).
frontal
postorbital
inguinal
notch
Fig. 7
xiphiplastron
Schematic ventral view of the plastron bones
ju g a l
parietal
prefrontal
maxill
supraoccipital
A x illa ry scutes - The va riab le n u m ber o f scutes
betw een the m arginal, hum eral and pectoral scutes,
on the rear margin o f the axillary notches (Fig. 3).
squamosal
Body pit - A depression made by the fem ale turtle on
the sandy beach, during nesting. Shape and depth o f
the pit are g eneric characteristics. The pits m ade by
the ridley, hawksbill and flatback are shallow (Fig. 8a),
w hile those o f the loggerhead, green and leatherback
are m edium to deep (Fig. 8b). Some turtles (e.g., green
turtle) construct several body pits before they lay the
m axilla
coronoid
quadratojugal
dentary
angular
Fig. 6
surangular
Schematic skull of an adult Kemp's ridley, showing
basic structures (adapted from Romer, 1956)
eggs.
6
Carey - See tortoise shell.
Caruncle - Sharp horny tubercle on the tip o f the upper
tom ium o f new born hatchlings; used to pierce the
egg-shell (Fig. 10). Usually disappears two w eeks after
h a tch in g .
a) shallow body pit
nest
caruncle
b) deep body pit
nest
Fig. 8
Female sea turtle in nesting attitude
Bridge bones - Ventral parts o f the shell that connect
the peripheral bones o f the carapace with the plastral
bones. The contact area may be calcified or cartilaginous
material (Fig. 7).
Fig. 10
Flead of a newborn Kemp's ridley hatchling
C alip a s h - C a rtila g in o u s s trip s ob taine d from the edge
o f the carapace or extracted as je lly from the dried
flippers. G enerally o f green colour when fresh.
Central scutes - The middle scutes covering the neural
plates o f the carapace, in between the lateral scutes.
Also named neural or vertebral scutes (Fig. 1).
C a lip e e - C a rtila g e e x tra c te d from th e b o rd e r o f the
plastron, along the axillary and inguinal notches, the
bridge and between the bones o f the plastron. Calipee
and calipash are used for the preparation o f turtle soup.
Cervical vertebrae - A n te rio r (8) bony elem ents o f the
v e rte b ra l colum n. In tu rtle s, the neck is ty p ic a lly
retractile. The shortening o f the neck in sea tu rtle s is an
adaptation to marine life (Fig. 4)
Carapace - Dorsal o sseous shell o f the tu rtle covered by
horny scutes or soft skin (Figs. 1,4).
C h o a n ae - The in te rn a l o p e n in g s o f the n a sa l fu n n e ls
through the vom erian bones on the palate (Figs 5, 13).
Carapace length - Distance either in straight-line (SCL)
or over the curve (CCL), between the anteriorm ost edge
CITES - An acronym for “Convention on International
Trade in Endangered Species o f W ildlife and Flora” . The
IUCN determ ines the criteria for addition o f species and
other taxa to A ppendix I (Endangered) and A ppendix II
(Threatened) o f CITES, and for the transfer o f species and
o ther taxa from A ppendix II to A ppendix I. All the sea
tu rtle s are included in Appendix I, because th e ir survival
is affected by international trade.
to the rearm ost edge o f the carapace (Fig. 9).
CCL
SCL.
Claw - Sharp, horny nail on the a n terior m argin o f the
flippers. The claw s (usually one or two on each flipper)
are more strongly developed in m ales than in fem ales,
and they are used to hold the fem ale during copulation
(Figs 1,3).
Clutch size - Total num ber o f eggs laid sim ultaneously to
form a nest (Fig. 8).
Fig. 9
M easurem ents of carapace length
Carapace w id th Distance in straight-line or over the
curve across the widest part o f the carapace, m easured on
its dorsal side (Fig. 1).
C o ro n o id b o n e s - F lat, p a ire d , b o n y e le m e n ts o f the
low er m andible (Fig. 6).
Costal plates - Expanded, ossified derm al plates fused to
the axial skeleton (vertebrae and ribs), betw een the
peripheral and neural plates o f the carapace (Fig. 11).
7
nucal plates
fontanelles
Fem oral scutes - The pair o f posterior plastral scutes in
contact w ith the abdom inal, infram arginal and anal
scutes (Fig. 3).
"F lo tilla" - Spanish name for a large num ber o f m igrant
tu rtle s drifting or swim m ing together in the open ocean.
ribs
costal
plates
neural
plates
(1-8)
Fontanelles - C arapacial unossified areas between the
peripheral and costal bones, usually disappearing with
age (Fig. 11).
Frontal bone - The long bone above the orbit on each
s id e o f th e s k u ll (F ig . 6).
G uiar scutes - The forem ost paired scutes o f the plastron
(Fig. 3).
H abitat - The environm ent in which a species usually
o ccu rs.
vertebrae
peripheral
plates
pigal plates
Fig. 11 Carapace bones in schem atic ventral view of
a ju v e n ile g reen sea tu rtle, sho w ing the
characteristic fontanelles of premature ages
Craw l - S ym m etrical tra ct left by the fore and rear
flippers o f tu rtle s on the sandy beach. Sizes and shapes
o f the crawl are considered characteristic for the species.
Cusp - Sharp projection, usually on the tip o f the jaw s
(Fig. 12).
H atchery - Construction for the incubation o f eggs and
relea sin g o r rearing the produced ha tchlig s. The
incubation o f eggs can be done in fenced areas o f the
beach or indoors, under se m i-controlled conditions,
using styrofoam boxes.
Head length - The distance between the tip o f the beak
and the posterior margin o f the head (Fig. 1).
Head-starting - The practice o f raising hatchling turtles
in ca p tivity fo r a few m onths to give them a better
chance o f survival when they are later released into the
w ild .
Head w idth - The distance across the widest part o f the
head (Fig. 1).
Hum eral scutes - The a n te rio r paired scu te s o f the
plastron, between the guiar, pectoral and axillary scutes
(Fig. 3).
H yop lastron plates - The m edian-front
plates o f the plastron (Figs. 4, 7).
paired
bony
H ypo p lastro n plates - The m edian-rear
plates o f the plastron (Figs. 4, 7).
paired
bony
Im bricate - O verlapping condition (like shingles on a
roof) o f the scutes o f the carapace and plastron in the
hawksbill sea turtle. Hatchlings and ju ve n ile s o f other
species commonly also have this condition.
cusps
Fig. 12 Beak cusps on ja w s of adult leatherback sea turtle
Im printing - Theoretical procedure by which a sea turtle
hatchling
u nconsciously
“m em orizes”
environm ental
cues o f its natal beach, that enable it to relocate the
same beach when mature.
Dentary bone - Largest elem ent o f the low er jaw, the
principal support o f the lower tom ium (Fig. 6).
Incid ental catch - The u n in tentional catch o f nontargetted species, such as tu rtle s and bottom fishes
during shrim p trawling.
Endem ic - Found only in a lim ited region.
E n to p la s tro n p late - M edian bony plate lying betw een
epiplastra and hyoplastra (Figs. 4, 7).
Epifauna - Those anim als living on the body o f a turtle.
Epiplastron plate - The forem ost paired bony plates of
the plastron (Figs. 4, 7).
Farm ing - The culturing o f sea tu rtle s in tra cts o f sea
w a te r for com m ercial purposes. It m ust not rely on wild
populations except initially or later occasionally, to avoid
inbreeding problem s and genetic degeneration.
Incu bation period - The tim e elapsed betw een egg
laying and hatching. In sea turtles, it ranges from 45 to
about 70 days, depending on species, tem perature,
hum idity and latitude.
Indigenous - An organism that originated and is living
in a specified region (see endemic).
Infram arginal pore - A single, sm all orifice through each
in fra m a rg in a l scute, serving as the ou tle t for the
R athke’s gland secretions; th e ir function is unknown.
These pores are present principally in turtles o f the genus
L e p id o c h e ly s (F ig . 3).
8
Infram arginal scutes - The scutes covering the bridge
bones, between the ventral side o f the m arginal scutes
and the central scutes o f the plastron (Fig. 3).
Niche - The habits or role o f an organism in a particular
com m unity. M ainly concerned w ith the food chain,
com petitors and enemies.
Inguinal notch - The cavities on each side o f the plastron
from which the rear flippers project (Fig. 7).
Nucal bones (or plates) - The bones (usually two)
form ing the forem ost central part o f the carapace (Figs
4, 11).
Interanal scute - The middle, rearm ost plastron scute or
scutes between the pair o f anal scutes (som etim es absent)
O rbital length - Longitudinal diam eter o f the eye socket
(Fig. 3)
(Fig. 2).
Intergular scute - The middle, forem ost plastron scute or
s cu te s betw een the p air o f g u ia r scu te s (som e tim es
a b s e n t) (Fig. 3).
Papillary projections - Spine-like grow ths present in the
throat o f the sea turtles; they are more conspicuous in
th e le a th e rb a c k s (Fig. 13).
Isotherm - A th e ore tica l w arped plane or line
w a te r connecting points o f equal tem perature.
in the
choanae
I.U.C.N. - An acronym for the International Union for the
Conservation o f Nature and Natural Resources.
Jugal bone - The long bone under the orbit, form ing part
o f the cheek region on each side o f the skull (Fig. 6).
papillae
Kraal - A pen used for holding tu rtle s before slaughter;
also an a rtific ia l beach fo r nesting p urposes, an
installation used to protect nests on a beach, or a fenced
area against predation. Also called “co rra l” .
Lateral scutes - The lateralm ost scutes covering the
carapace on both sides, between the central and marginal
scutes. Also named pleural or costal scutes (Fig. 1).
L ep ido sis - C o n fig u ra tio n o f the sca le s and scutes
covering the body; o f ta xo no m ic value at ge n us level
(Figs. 1 3 ) .
L ost y e a r - The e la p se d tim e b etw een new born
ha tchlin gs and grow th to sm all-p la te -size ju ve n ile s,
during w hich the tu rtle is rarely encountered and its
h a b its are la rg e ly u n kn ow n.
M arginal scutes - The scu te s covering the peripheral
bones o f the carapace, form ing a hard edge all around it
(Fig. 1).
M axilla - The large bone extending up to the orbit and
form ing, with the prem axilla, the upper jaw m argin (Fig.
6 ).
M elan ism - The propensity o f an organism to develop
d a rk p ig m e n t th ro u g h o u t th e skin.
M entonian scute - The scute under the tip o f the lower
tom ium (Fig. 3).
Nares - Pair o f openings into the nose, the nostrils (Figs
12,14).
Nekton - Free-sw im m ing organism s whose activity largely
d e term in e s d irection and speed o f th e ir m ovem ents,
independent o f w ater currents.
N eritic s h e lv e s .
R elating
to
the
w a te rs
over the
continental
Nest - The cavity w here the eggs are laid by the turtles.
Shape and depth differ by genus (Fig. 8). It is also related
to the clutch o f eggs.
Neural plates - Carapacial osseous plates fused to the
v e rte b ra e (F ig s 4, 11).
Fig. 13 Buccal cavity of a leatherback sea turtle
Parietal bones - The m ajor elem ents o f the skull roof
between and behind the orbits (Fig. 6).
Pectoral girdle - Bones form ing the support for the fore­
lim bs or anterior flippers (Fig. 4).
Pectoral scutes - The m edian pair o f scutes in contact
with the hum eral, infram arginal and abdom inal scutes
o f the plastron (Fig. 3).
Pelvic girdle - Bones form ing the support for the hindlim bs or posterior flippers (Fig. 4).
Peripheral bones (or plates) - O sseous elem ents forming
th e edge o f th e c a ra p a c e (Fig. 11).
P hilopatry - T endency o f sea tu rtle s to nest in, or very
near to, the previous nesting place, during the same or in
successive breeding seasons. Also called “nesting site
fixity or fidelity” .
Pigal bones (or plates) - The rearm ost marginal osseous
plates that form the carapace (Figs 4, 11).
Pigal scutes - The rearm ost pair o f marginal scutes o f the
carapace. A lso
nam ed
p o stcentral,
su p ra p ig a l,
or
s u p ra c a u d a l s c u te s (F ig . 1).
Pivotal tem peratu re - Theoretical tem perature at which
in c u b a tio n p ro d u c e s a se x ra tio o f 1:1.
Plastron - Ventral osseous shell o f the turtles, covered by
h o rn y s c u te s o r s o ft skin (F ig . 3 ,4 ,7 ).
9
Postcentral scutes - The rearm ost pair o f marginal scutes
o f the carapace. Also named suprapigal, supracaudal or
pigal scutes (Fig. 1).
Postorbital bone - The bone behind the orbit that form s
p a rt o f e a ch c h e e k o f (F ig . 6).
Postorbital scales - The horny scales (usually 3 or 4)
covering the sides o f the head behind the orbits (Fig. 14).
p re fro n ta l
Ribs - Beneath the carapace o f ch e lo n ia ns there are
eight pairs o f dorsal ribs fused to the costal or pleural
and to the neural plates. The tips o f the ribs are inserted
in ventral pits o f the peripheral bones (Figs 4, 11).
Scales - Thin, leathery or horny shields covering the head
and flippers and form ing callosities in some parts o f the
flippers (Fig. 14).
Scu tes - Horny sh ie ld s covering
plastron. The shape and size do not
underlying bony plates. The thickest
scutes are those o f the hawksbill turtle
sc a le s
the carapace and
correspond w ith the
and m ost valuable
(Figs 1,3).
S exu al
d im o rp h is m
M orp h o lo g ica l
d iffe re n ce s
betw een m ales and fe m a le s th a t a p p ea r at sexual
m aturity. M ales develop stronger claw s and th icke r and
longer ta ils (Fig. 3). Fem ales become heavier and have a
deeper body shape.
p o s to rb ita l
sca le s
Squam osal bones - The p rincipal
cheek region o f the skull (Fig. 6).
com ponent
o f the
S upracaudal scutes - The rearm ost pair o f m arginal
scutes o f the carapace. Also named postcentral, pigal or
suprapigal scutes (Fig. 1).
to m ium
(break)
Supraoccipital bones - Paired bones o f the upper part o f
the occiput at the back o f the skull (Fig. 6).
Fig. 14
Head showing disposition of scales in a
green turtle (schematic)
Suprapigal scutes - The rearm ost pair o f marginal scutes
o f the carapace. A lso nam ed po stcen tra l, pigal or
supracaudal scutes (Fig. 1).
S u rangular bones - The upper posterior bones o f each
ra m u s o f th e lo w e r ja w (F ig . 6).
Precentral scute - The forem ost central scute o f the
carapace (Fig. 1). Also named prevertebral, nucal or
c e rv ic a l scu te .
P re fro n ta l b ones - A p air o f circu m o rb ital bones,
extending an terio rly and also bordering the external
n a re s (Fig. 6).
Prefrontal scales - Usually 1 or 2 pairs o f horny scales
covering the anterior interorbital area (characteristic at
g e n e ric le v e l) (Fig. 14).
Prem axilla bones - The paired bones form ing the front
m argin o f the snout, supporting, to g e th e r w ith the
m a x illa , the u p p e r to m iu m (Fig. 6).
Preorbital length - The shortest distance between the
a n te rio r m argin o f the orbit and the tip o f the snout.
A ls o c a lle d p re o c u la r le n g th (F ig . 2).
Q uadrate bone - Thick bone close to the jaw articulation.
Laterally, it is bound to the quadratojugal bone (Fig. 6).
Ranching - The raising o f turtles from wild stock eggs or
h a tc h lin g s to m a rk e ta b le size .
T .E .D . - An acronym
fo r “traw l e fficie n cy d e vice ” or
“tu rtle
e xclu d e r
d e v ic e ” .
O rigina lly,
a
co lla p sib le
structure fitted to a shrim p trawl net, designed to reduce
incidental catch, especially o f sea turtles. Today there are
several kinds o f T.E.D.'s tested and approved by the US
N a tio n a l M a rin e F is h e rie s S e rvice .
To m iu m - The horny beak th a t co ve rs the a lve o la r
surface o f the m andibles o f birds and tu rtle s. In sea
turtles, the cutting edges can be sm ooth or serrated
(F ig s. 5, 14). A lso kn ow n as ra m p h o te ca .
T ortoise shell, o r "c a rey " - The generic name for the
scutes o f the plastron and carapace o f the hawksbill,
used in je w e lle ry and h a n d y c ra ft w o rk.
Total length - The straig h t-lin e distance between the
sn o u t and th e re a rm o s t pa rt o f th e c a ra p a c e (F ig . 1).
Verteb rae - The elem ents o f the vertebral colum n or
axial skeleton. In turtles, the dorsal and sacral vertebrae
are deeply m odified and d o rsa lly fused to the neural
p la te s o f th e ca ra p a ce (F ig s. 4, 11).
Rem igrant - T urtles that return to nest in a subsequent
se a s o n .
Vom erine bone - One o f the pairs o f osseous elem ents
centrally placed behind the prem axillae and form ing a
b a r b e tw e e n the in te rn a l n o s trils o r ch o a n a e .
Renesting - Successive visits o f a turtle to a nesting area,
la y in g e g g s e ach tim e.
X ip h ip las tro n bones - The
form ing the plastron (Figs 4 ,7 ).
rearm ost
p air
of
bones
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10
2.
SYSTEMATIC CATALOGUE
2.1 Illustrated key to Families and Genera (adult stages)
1a. Body w ithout horny scutes, covered
by leathery skin, sm all scales present
only in hatchlings; carapace w ith 5
dorsal longitudinal ridges (Fig. 15b);
upper tom ium with a pair o f frontal
cusps (Fig. 15a). Choanae open in
two separate apertures on anterior
h a lf o f palate. P atches o f papillary
cusps
p ro je c tio n s a rranged in row s on
palate and flo o r o f m outh and in
th ro a t (Fig. 16a). F lippers w ithout
visible claw s .... FAMILY DERMOCHELYDAE
rid g e s
a) head
b) carapace
Derm ochelys
(D erm ochelys)
1b. S cu te s
c o ve rin g
ca ra p a ce
and
plastron; scales present on head and
flippers. Choanae open in a single
aperature on the rear h a lf o f palate
(F ig .1 6 b ).
P a p illa ry
p ro je ctio n s
absent in m outh, but present in the
th ro a t. F lip pe rs w ith one or two
Fig.15
2 choanal
o p e n in g s
a s in g le
choanal
o p e n in g
p a p illa e
developed claws ........ FAM ILY CHELONIIDAE
2a. Carapace with 4 lateral scutes on
each side, the first pair not in
contact with the precentral scute
(Figs 17, 18, 19)
3a. Carapace elliptical, covered
by im bricate scutes (Fig. 15b)
except in very old individuals.
Head narrow, with two pairs
o f prefrontal scales; tom ium
haw klike, not serrated (Fig.
17a). F lippers usually with
two evident claws ...... Eretm ochelys
lo w e r ja w
lo w e r ja w
a)
Derm ochelyidae
b) cheloniidae
ventral view of head (mouth open)
Fig.16
im b ric a te s c u te s
2 p a irs o f
p re fro n ta l s c a le s
p re c e n tra l
s c u te
h a w klike
ta m iu m
4 la te ra l s c u te s
b) carapace
E re tm o c h e ly s
F ig .17
11
1 pair of
prefrontal scales
4 lateral scutes
3b. C arapace nearly oval, with no
im bricate scutes (18b). Head
b lu n t
(s h o rt
s n o u t),
th e
p re o rb ita l
d ista n ce
cle a rly
sm alle r than orbital length; a
single pair o f prefrontal scales,
usually 4 po storb ita l scales;
tom ium
se rra te d
(Fig.
18a).
F lippers usually w ith only one
evident claw ..................... C helonia
ù
x precentral
(u i
scute
t
f t
4 postorbital
scales
3c. C a rapace
ne a rly
round
and
flattened, w ith slightly upwardfolded
m argins,
co ve re d
by
ra th e r
th in ,
n o n -im b rica te
scutes, w axy to touch (Fig 19b);
preorbital distance nearly equal
to orbital length; a single pair
o f prefrontal scales, usually 3
postorbital scales; tom ium not
serrated
(Fig.
19a). F lippers
with one evident c la w
N a ta to r
a) head
Fig.18
C h elo nia
4 lateral scutes
preorbital
distance
precentral
scute
2b. Carapace with 5 lateral scutes on
each side, the first pair in contact
w ith th e p re c e n tra l scute (F ig s
20 ,21 )
4a.
\
C a rapace
ca rd ifo rm ,
its
length alw ays greater than
th e
w id th
(F ig .2 0 b ).
Plastron usually with 3 pairs
of
in fra m a rg in a l
scutes,
g e n e ra lly
w ith o u t
pores
(fig. 20c). Carapace scutes
th ic k and rough to touch.
Head relatively large, with
a heavy and strong tom ium
lacking an internal alveolar
rim (Fig. 20a). Body colour
usually
reddish-brow n
or
yellow ish-brow n ......... Caretta
usually 3
postorbital scales
b) carapace
a) head
N a ta to r
Fig.19
3 Inframarginal
scutes without pores
2 p airs of
postorbital
scales
5 lateral scutes
¿
i
precentral
scute
a) head
c) plastron
b) carapace
Caretta
Fig.20
12
4b. Carapace nearly round, its length sim ila r to the
w idth (Fig. 2 1 b ). Plastron usually with 4 pairs o f
pored infram arginal scutes (Fig. 21c). Carapace
scutes sm ooth to touch. Flead m oderately small,
w ith a cutting tom ium provided w ith an internal
alveolar rim (Figs 5, 21a). Body colour grey-olive
or o liv e -y e llo w ish .............................................. Lepidochelys
a) head
4
5 lateral scu tes
infram arginal
scutes
each w ith a Pore
p re c e n tra l
scute
..
b)
c) plastron
' r
carapace
Lepidochelys
Fig-21
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13
CHEL
2.2 FAMILY CHELONIIDAE
Synonym s : Cheloniadae; C h e lo n iid a e ; Chelonidae; Chelonydae.
D iagnostic Features : Flard-shelled turtles w ith paddle-like limbs. Body depressed, but stream lined. Shell covered with
horny scutes, lim bs and head partially covered with rather thin scales. Vertebrae and ribs fused with the osseous
carapace plates. Neck incom pletely rectractile; a w ell-developed horny beak or tom ium covering both m andibles; a
v a lvu la r glottis occludes the th ro a t during im m ersions; no papillary projections in m outh. Paddle-like fore flippers
with 5 very elongated, nearly im m obile fingers, one or two claw s visible on the anterior border o f each flipper. Rear
flippers w ith partially mobile digits, with the same num ber o f claw s as the fore flippers. M ales are distinguished from
females by their longer tails and stronger claws. Eggs with a white, soft, papery shell.
G eographical Distribution, H abitat and B iology : The representatives o f this fam ily have a pantropical distribution,
w ith periodical or occasional m igrations into tem perate w aters for feeding, during warm w eather. A fte r the nesting
season, some chelonirds overw inter buried in m uddy bottom s o f shallow coastal w aters or m igrate to w arm er areas to
avoid freezing tem peratures. Nesting is perform ed on sandy beaches, ju st above the high tide mark; the clutch, o f
around one hundred eggs, is buried in the sand and left unattended. Depending on the species and w eather, hatching
occurs between 45 and 70 days after the eggs are laid; this incubation tim e is also influenced by the tem perature and
the hum idity in the nest. H atchlings apparently lead a pelagic-nectonic existence until they
reach ju venile size; this
period is known as the “ lost ye a rs” because so little is known o f this part o f th e ir
life history. There is also very little
inform ation on the habitat and behaviour in the juvenile and subadult stages. M ost cheloniids are carnivorous up to
adult age, although the green sea turtle changes to a vegetarian diet about the end o f the juvenile stage. M igrations
in large groups or “flo tilla s” , with sim ultaneous arrival at rookeries or nesting beaches (“arribazones”) are com m only
observed in these anim als. Usually, these arrivals have fortnighthly or alm ost m onthly periodicity and each fem ale may
come to nest in the same season from 2 to 5 tim es. It is assum ed that these synchronised nest-building arrivals are an
adaptative response to p re d a tio n on adults and eggs and are also favourable for survival o f the hatchlings which will
em erge from several nests at the same tim e and thus make it easier for at least some o f the young to avoid birds and
terrestrial predators in their race to the sea.
T urtles are highly vulnerable to predation, the kind o f predator depending on th e ir developm ental stage. The eggs
are eaten principally by skunks, raccoons, opossum s, coaties, coyotes, badgers, dogs, jaguars, pigs, monkeys, varanid
lizards, ghost crabs, dipterous m aggots, ants, and beetles; also fungal and bacterial infections are com m on. The
hatchlings, ju st before erupting from the nest, can be attacked by ants, m ites and fly-m aggots, and the nest may be
opened by m am m als. W hen the hatchlings em erge from the nest, they race to the sea, and, on the way, they are
attacked by m am m als, birds and ghost crabs. In the water, predation continues, by birds at the surface and by fishes in
the w a te r colum n. Sharks and other fishes feed on ju venile sea turtles, but th is predation d im inishes w ith growth.
Except for man, the worst enemy o f the adult sea turtles are sharks.
Interest to Fisheries : All species o f C heloniidae are o f interest to fisheries. T heir products are highly valuable and
include meat, leather, eggs, scutes (Carey), oil and m eal or fertilizer. E gg-harvesting is now forbidden in nearly all
co u n trie s with nesting beaches. Because o f the severe depletion o f the m ajority o f w ild sea turtle populations,
now adays all species are considered as endangered and all o f them are listed in the Red Data Book o f the IUCN and
included in A ppendix I o f CITES. The com m erce o f turtle products
is restricted by international regulations, and all
signatory countries to CITES are com m itted to im plem ent m easures to conserve these species and avoid illegal trade.
The farm ing and ranching for com m ercial purposes o f some o f the species, are now under review and future activities
and regulations will be decided at the next meeting o f the IUCN.
Rem arks : This fam ily com prises 5 genera with 7 species. N a tato r depressus w as recently rem oved from Chelonia.
S u b species are recognized by several authors, but the separation o f these pop ulatio n s is u nclear and m ainly
substantiated through th e ir geographical distribution patterns (Carr, 1952; Loveridge and W illiam s, 1957; W erm uth
and M ertens, 1961; Smith and Smith, 1979).
CHEL Car
Caretta Rafinesque, 1814
G enus : Caretta Rafinesque, 1814.
Specchio
Type Species : Testudo caretta Linnaeus 1758,
Sei. Palermo, 2(9):66
Syst. Nat., Ed. 10, T. 1 : 197
Synonym s : Thalassochelys Fitzinger, 1835; Caouana Cocteau, 1838; Halichelys Fitzinger, 1843; Cephalochelys Gray,
1873; Eremonia Gray, 1873.
Diagnostic Features : See species.
Rem arks : This genus includes a single species: Ca. caretta, which w as subdivided on the basis o f its m orphology and
geographical distribution in two subspecies, Ca. c. caretta and Ca. c. gigas, some authors consider these ta x a as
separate species.
Caretta caretta (Linnaeus, 1758)
Fig. 22,23
CHEL Car 1
Testudo caretta Linnaeus, 1758, Svstema N aturae. Ed. 10, T. 1: 197 (Islands o f Am erica)
Synonym s : Testudo Cephalo Schneider, 1783; Testudo nasicornis Lacepède, 1788; Testudo Caouana Lacepède, 1788;
Chelone caretta: Brongniart, 1805; Chelonia Caouanna: Schweigger, 1812; Caretta nasuta Rafinesque, 1814; Chelonia
cavanna Oken, 1816; C aretta atra M errem, 1820; C aretta Cephalo Merrem, 1820; C aretta n asico rn is: Merrem, 1820;
Chelonia caretta: Bory de Saint Vincent, 1828; Testudo Corianna Gray, 1831; Chelonia pelasgorum Valenciennes, 1833;
Chelonia cephalo'. Tem m inck and Schlegel, 1834; Chelonia (Caretta) cephalo'. Lesson, 1834; Chelonia caouana: Duméril
and Bibron, 1835; Chelonia (Thallassochelys) Caouana'. Fitzinger, 1836; C helonia (Thalassochelys) atra'. Fitzinger
1836; Thalassochelys caretta: Bonaparte, 1838; Chelonia (Caouana) cephalo'. Cocteau, 1838; Halichelys a tra : Fitzinger
1843; C aouana C aretta: Gray, 1844; C aouana e lo n g a ta Gray, 1844; T halassochelys C aou ana: Agassiz, 1857
Thalassochelys corticata Girard, 1858; Chelonia co rticata: Strauch, 1862; Thalassochelys elongata Strauch, 1862
Thalassiochelis caouana: Nardo, 1864; Erem onia elongata: Gray, 1873; Caretta caretta: Stejneger, 1904; Frazier, 1985
Thallasochelys cephalo'. Barbour and Cole, 1906; Caretta caretta c aretta: M ertens and M uller, 1928; C aretta gigas
Deraniyagala, 1933; C aretta caretta g ig as: Deraniyagala, 1939; Caretta caretta tarapacana Caldwell, 1962.
S ubspecies : The su bspecific status should be re-assessed because the two described subspecies, one for the Pacific,
Caretta caretta g ig as and the other for the Atlantic, Caretta caretta caretta, are not valid in the light o f available
info rm a tio n , since th e y w ere based on ch a ra cte rs show ing con sid e ra b le va riatio n , p rincipa lly colour, body size, num ber
o f neural and peripheral bones and num ber o f m arginal scutes (c a re tta 12-12, g ig a s 13-13). M ost a uthors now
recognize c a re tta as a single p o lym o rp h ic species.
FAO Species Nam es : En - Loggerhead turtle; Fr - Tortue caouanne; Sp - Caguama.
15
Diagnostic Features : In adults, the carapace in dorsal view
is heart-shaped, its w idth about 76 to 86% o f its length.
Head large, broad and subtriangular, 23 to 28% o f carapace
length, w ith 2 pairs o f prefrontal scales, and com m only one
in te r-p re fro n ta l; horny beak very strong, com paratively
th icke r than in other sea turtles. Carapacial scutes thin, but
hard and very rough, com m only covered w ith barnacles.
They include 5 pairs o f laterals, the a n terior touching the
precentral scute, 5 centrals (neurals), and com m only 12 or 13
pairs o f m arginals, including the postcentral or pygal scute.
U nderneath the bridge o f the plastron, there are 3 pairs o f
infram arginal scutes which rarely have pores. Fore flippers
relative ly short and thick, each w ith 2 visible cla w s on
a n terior m argin; rear flippers with 2 or 3 claws. H atchlings
and juvenile turtles have blunt spines on the carapace scutes,
form ing 3 lo n gitudinal ke e ls th a t d isa p p ea r during the
juvenile stage. Colour: The adults o f Caretta generally have a
constant dorsal pattern, easily recognisable by the reddishbrown colo ra tio n , so m e tim e s w ith dark strea ks (South
A frican turtles), that becom e orange-cream y on the flanks
and yellow -cream y underneath. The hatchlings are d a rk brown dorsally, w ith the flippers pale brown m arginally and
underneath, and the plastron usually is much paler.
G eog rap hical D istribu tio n
Caretta c aretta is w idely
distributed in coastal tropical and subtropical w a te rs (1620°C) around the w orld (Fig. 24). Com m only th is species
w a n d e rs into tem perate w a te rs and to the boundaries o f
warm currents. It is suspected that some loggerhead turtles
undertake long m igrations using warm currents (e. g., the
G u lf Stream in the North Atlantic; the North Equatorial and
Kuroshio C urrents and the C alifornia Current (12-20°C) in
the North P a cific and o th er cu rre n ts in the southern
hem isphere), th a t bring them fa r from the nesting and
feeding grounds. An exam ple o f such deplacem ents is the
recapture o f a juvenile released at Okinawa Island on 22 July
1985, and recaptured o ff San Diego, California two years and
precentral
/ scute
2 claws
m arginal
> scutes
central
scutes
5 lateral
scutes
interprefrontal
scale
prefrontal
scales
3 infra­
m arginal
scales
(poreless)
dorsal view of head
plastron
Fig.23
?
1 20 °
100 °
160 °
1 80 °
Fig.24
16
four m onths later (U chida and Teruya, 1988 ms). There are groups o f tu rtle s reported from open seas, e.g., the
encounter o f thousands o f juvenile loggerheads swim m ing w estw ard o ff G ibraltar (33°N. 14’ W ), or in the W estern
A tlantic, 700 to 900 km o ff the coast o f Uruguay, or 50 to 60 km w est o f Bahia Tortugas and T odos Santos Bay, along
s outhern Baja C a lifornia, M exico. T his la tte r lo ca lity se e m s to be a sp rin g -su m m e r feeding ground for th o u sa n d s o f
juvenile, subadult, and a few adult loggerheads. This species is capable o f living in a variety o f environm ents for a
relatively long tim e, such as in brackish w aters o f coastal lagoons and river m ouths. It may remain dorm ant during the
winter, buried in m uddy bottom s located in m oderately deep w aters such as sounds, bays and estuaries, e.g., Cape
Canaveral in Florida. Apparently, the lim it o f distribution is w aters o f about 10°C; if they encounter colder waters,
they may become stunned, drift helplessly and strand on nearby shores. Records are quoted from New England and
eastern Canada, Labrador and Nova Scotia, especially between July and O ctober o f warm years. The northern lim it of
distribution is a sum m er capture o f a live young turtle entangled in a fishing line o ff M urm ansk, Barents Sea (68°
55’N). Brongersm a (1972) quotes this and many other records for European waters. Occasionally, the species is sighted
in southern Australia and New Zealand. In South Am erica it is absent from west Colom bia, Ecuador and Peru, but there
are some records from Arica and Coquimbo, in Chile; on the eastern coast, the southernm ost record is Rio de la Plata,
A rgentina.
H a b ita t and B io lo g y : T h is tu rtle p rim a rily is an in h a b ita n t o f c o n tin e n ta l sh o re s o f w a rm se a s, co m m o n in
shallow waters, but it also lives around some islands as: M asirah in Oman, Z akinthos in Greece, and the Ryukyu and
Japan Archipelago. The most im portant aggregations are tem porarily form ed ju st o ff the nesting beaches at the end
of the spring, in sum m er and at the beginning o f autum n. In some places, the nesting grounds are associated with
underw ater “refuges” , such as crevices in rocky or ree f points, near to the nesting beaches w here the turtles remain
throughout the reproductive period, e. g., Gamoda Beach in Japan (Uchida, pers. corn., 1977). It is possible that these
places could be associated with nesting site fixity. This is the only sea turtle that can nest successfully outside o f the
tropics, but the summ er surface temperature must be over 20°C .
During, or soon after the breeding season ends, some fem ales disperse to distant feeding grounds. M igratory routes
are not clearly delineated, but hatchlings theoretically follow warm currents such as the G u lf Stream, or may enter the
big gyre o f the North Pacific Ocean, along the Kuroshio, the California and the North Equatorial currents. It is possible
that if they are “trapped” by these enorm ous warm currents and com plete the intercontinental circuit (gyre) they may
be near maturity when they are carried back to their natal beaches.
Loggerhead hatchlings and ju ve n ile s are frequently associated w ith sea fronts (oceanic current convergences),
dow nw ellings and eddies, w here floating epipelagic anim als and floatsam are gathered. The elapsed tim e, usually
more than a year - during which the sm all tu rtle s rem ain in those places feeding and grow ing - is called the “lost
ye a r” . During this first period o f life there is evidence that these turtles lead a pelagic-nectonic existence, feeding on
organisms usually associated with sargassum mats.
There are several m ajor nesting grounds, and some o f them are located in northern latitudes. In general, the
loggerhead does not form “arribazones” but nests on large beaches. The m ajor nesting grounds are located inthe
southeastern USA, principally in Florida and South Carolina with a mean annual production (in 1986) o f about 24 000
and 4 000 nests respectively; in Florida, the nesting is much more im portant on the A tlantic than on the G ulf coast:
G eorgia with 1 250, and North Carolina with 280 nests per year. In the eastern USA, m inor and solitary nesting occurs
as far north as New Jersey.
Along the G u lf o f Mexico coasts, only m inor and solitary nesting is recorded. In Mexico, on the northeastern coasts of
the Yucatan peninsula and in Quintana Roo State, sm all groups o f tu rtle s occur from Cape Catoche and Contoy Island
to A scención Bay, with a relatively greater abundance between Carm en Port and Ascención Bay, including Cozumel
Island and Boca Paila Beach as the more im portant nesting places in this region. M inor nesting beaches are located on
som e islands o f the C aribbean region, principa lly on the so u th-ce n tra l coasts, islands and cays o f Cuba.
G oing so u th in th is re g io n , o th e r n e stin g is n e g lig ib le , e x c e p t fo r C o lo m b ia , w h e re th e re m a in s o f an im p o rta n t
nesting aggregation is reported, especially to the east side o f Santa Marta, between the rivers Piedras and Riohacha
(which includes the Buritaca Reserve). It w as calculated that about 2 000 nests were laid every season in this area, but
they have recently declined to a few hundred. East o f Colom bia, the presence and nesting o f loggerheads are
negligible. In Brazil, e.g., M aranhao and Ceara. an annual production o f over a thousand nests is reported; nesting is
consistently reported from Sergipe and also occurs in the states o f Bahia, Espirito Santo and Rio de Janeiro. Subadult
and few adult loggerhead tu rtle s have been reported as far south as Uruguay, e specially betw een Rocha and
Maldonado, including the area o f Rio de la Plata. Nesting does not occur this far south.
In the M editerranean Sea, Caretta is the m ost comm on turtle, and it is regularly captured either directly or incidentally.
Nesting is reported principally from the coasts o f Greece, Turkey to Israel, Tunisia, both coasts o f Italy, Sicily and
historically from Sardinia and Corsica; in C yprus and Algeria, nesting w as form erly more w idely and consistently
observed, but now adays occurs only from tim e-to-tim e. The annual production o f nests, in all o f the M editerranean
continental rookeries w as believed not to exceed 1 000 nests, but recently the Z akinthos Island, in G reece, was
17
indicated as an im portant nesting place, with over 2 000 nests per year. In the southern M editerranean, the northeast
coast o f Libya is known as a m inor nesting beach. Caretta is also reported from the Iberian peninsula, but no nesting
has been observed there up to now. The w estern and the southw estern coasts o f the Black Sea probably also have
sporadic nesting.
On the Bahamas, Bermuda and the oceanic North A tlantic Islands
com m only observed (reported from around M adeira, the Canary
apparently originate in the W estern A tlantic rookeries, from which
these islands. These oceanic gyres and eddies are considered as
loggerheads reach the last juvenile stages.
nesting does not occur, but juvenile loggerheads are
Islands and especially the Azores). These tu rtle s
hatchlings enter the G ulf Stream and are carried to
feeding grounds and developing habitats, w here the
In the Eastern Atlantic, m inor nesting takes place in Morocco, the Cape Verde Archipelago and on the coast o f Senegal
(Dakar). In the G ulf o f Guinea, loggerheads may nest, but no reports are as yet available from this area. M inor nesting is
reported for southern Angola and northern Namibia, known in the region as the “Skeleton coast” .
M ajor Indian Ocean nesting grounds occur in South Africa, especially in the northeastern part o f Tongaland on the
Natal coast, w here the nesting population com prises several hundred fem ales. O ther im portant nesting grounds are
those in southern M adagascar, but no m ention is made o f the Com ores A rchipelago in the com pilation prepared by
Frazier (1985). Further north, the largest known breeding aggregation occurs on the Arabian peninsula, described in
1979 as the m ost im portant rookery for loggerheads in the world, with an annual rough estim ate o f 30 000 nesting
fem ales on M asirah Island, Sultanate o f Oman alone; other nesting may occur in the area but it is negligible and there
is apparently no nesting in the Red Sea or the Persian (Arabian) Gulf.
Around the islands o f the Indian Ocean, th is species is nearly unknown. There is m inor turtle nesting in Kosgoda,
southwestern Sri Lanka, where ridleys and green turtles are common, but loggerheads are rare.
In China, nesting occurs along the coasts o f the South China Sea, principally in Flainan Island. Caretta is frequently
observed from Kuangsi (south) to Hopei (north) in Taiw anese waters, but w ithout nesting records. Going northeast,
nesting occurs just up to Japanese waters, especially on the southern islands, from the Ryukyu A rchipelago to Kyushu
and Shikoku Islands. The northernm ost point o f nesting in the W estern Pacific is about 37°N, on the east coast o f
Honshu Island, w here Caretta is the most abundant o f all sea turtles. In the w estern Pacific, nesting is m entioned, but
not quantified for w aters o f Sumatra, Borneo, Sabah, Philippines, Indochina, M alaysia and Thailand; from the Arafura
Sea to Australia, the loggerhead not only nests, but is recognized as being very com m on. For the coasts o f western
A ustralia (Shark Bay and Barrow Island) and Queensland, south o f the Great Barrier R eef (Mon Repos-Bundaberg, Crab
Islands and Swain Reefs Islands) there are estim ates o f annual num bers o f over 3 000 females. Records are also available
from around Papua New Guinea and New Caledonia, but they become less frequent in New Zealand w aters and nearly
absent in the western and central Pacific O ceanic Islands, except Tokelau, Fiji, New Caledonia and Solomon, w here they
are reported as rare. Those records have been apparently confused with the olive ridley (L. olivacea). In the Hawaiian
Archipelago, Caretta is not common, and nesting does not occur.
In the Eastern Pacific Ocean, nesting o f Caretta w as reported from the G ulf o f Panama and El Salvador, but it is unclear
w hether the identification o f the species w as accurate. It w as very probably confused with the olive ridley (L. olivacea).
Loggerheads are absent on the coasts o f Colom bia, Ecuador and Peru. There are also several non-nesting reports from
Chile.
Thousands o f loggerheads appear during spring and sum m er in Baja California and the G u lf o f California w aters, but
apparently all these turtles are non-reproductive, m easuring between 25 and 92 cm o f CCL. Until now, no turtle in this
area has been reported bearing mature eggs.
Nesting o f C aretta usually occurs in spring and sum m er, w ith variations according to the latitude and geographical
ch aracteristics o f the coast. Data available in the literature show that the nesting season also varies in extent: In the
C aribbean area it extends from April to July or the first w eek o f August, with the peak in May or June (principally
southern Cuba and Quintana Roo, Mexico). In the northwest A tlantic Ocean, from April to Septem ber, with the peak in
June-July (Florida). In the southw estern Atlantic, from April to August, with the peak in June (Colom bia). In the Eastern
Atlantic, from June to Septem ber (eastern M editerranean, Turkey, Libya, and Z akinthos Island, Greece), and from July
to O ctober (Senegal). In the southw estern Indian Ocean from O ctober to February, w ith the peak in Novem berD ecem ber (South Africa: Natal-Tongaland). In the northw estern Indian Ocean, from May to June, but there are also
reports for the w inter from N ovem ber to M arch, with the peak in D ecem ber-January (M asirah Island, Oman). In the
east up to Sri Lanka, questionable reports that may correspond to Lepidochelys olivacea, state that the season runs in
the w inter, starting from S eptem ber and lasting seven m onths up to the next year. In the N orthwest Pacific Ocean
there are no big nesting grounds; in China, the season goes from April to A ugust with a peak in June or July; in Japan
(Honshu, Kiushu and the Ryukyu Archipelago), the situation is sim ilar, but the season starts e arlier in the southern
beaches and also has the peak in June or July. In Australia, the season runs from O ctober to April, with the peak
between November to January. No nesting is reported from New Zealand.
18
Caretta show s renesting frequency intervals o f nearly two weeks; fem ales usually lay between two and five tim es per
season, depositing on each occasion from 40 to 190 eggs (mean: 110 eggs). Hence, a single fem ale could lay a
m aximum o f 560 eggs per season. The m ajor pattern o f the reproductive cycle is two or three years, but some parts o f
the population may shift from one cycle to another, including to a yearly cycle.
The size o f the egg clutch varies from place to place, from a minimum o f 23 to a maximum o f 190 eggs per clutch.
Som e exam ples are the follow ing: USA - North C arolina from 86 to 159 eggs, with a mean o f 123 (n = 26 nests); -South C arolina from 64 to 198 eggs,
w ith a mean o f 126 (n =7 1 nests); - Georgia, C um berland Island w ith a m ean o f 120 eggs (n = 2 827 nests); Florida, Broward C ounty from 53 to 174
eggs, w ith a m ean o f 107 (n = 1928); M errit Island, from 82 to 173 eggs, w ith a m ean o f 123 (n = 64); M e x ico -Q u in ta na Roo, M ujeres Island from 68
to 188 eggs, w ith a mean o f 97 (n =66); -continental beaches o f the sam e state, from 45 to 183 eggs, w ith a mean o f 103.5 (n=795); C o lo m b ia Buritaca River, from 58 to 163 eggs, w ith a mean o f 106.5 (n = 254); G re e ce - Zakinthos Island, from 52 to 114 eggs; T u rk e y-M ed ite rra ne a n coast,
from 23 to 134 eggs, with a mean o f 93 (n = 50); Om an - M asirah Island from 72 to 130 eggs, w ith a mean o f 101 (n = 29); South A frica - Tongaland,
fro m 55 to 160 eggs (n=98), and a m ean o f 114 (n= 112), o th e r tw o m e asu re m e nts give m eans o f 113 and 105.3 eggs (n=41 and 72 nests
respectively); A ustralia - M on R epos Bundaberg from 48 to 190 eggs, with a mean o f 127 (n = 1 056 nests). The general m inim um and m axim um
averages for the species in Turkey and Australia are 93 and 127 eggs, respectively.
In general, the egg size in d ia m e te r and m ass usually v a rie s p ro p o rtio n a lly to the size o f the tu rtle , hence sm all tu rtle s
lay sm aller eggs. The egg diam eter ranges from 34.7 to 55.2 mm.
V ariations in d ia m e te r size have been quoted by several authors, e.g , in USA, South Carolina, it varies from 35 to 49, hence, with a mean of 41.5 mm
(n = 4 4 clutches w ith 827 eggs); in Florida, M e rritt Islands, mean m easurem ents range from 39.2 to 44.6 mm, w ith a general m ean o f 42.1 mm
(n = 5 666 eggs); in C ape C anaveral, the minimum and maximum sizes o f the eggs w ere 37 and 55.2 mm respectively, w ith a m ean o f 42.2 m m (n = 44
clutches w ith 4 804 eggs); in M e xic o ,Q uintana Roo, a mean o f 43 mm w a s obtained (n= 10 100 eggs); in C olom bia, Buritaca River, egg dia m e te rs
ranged from 39.7 to 47.5 mm, w ith a mean o f 43.3 mm (n = 3 370 egg); on the M editerranean coast, in southw est Turkey, from 37 to 42 mm, w ith a
mean of 39 mm (n = 50,500 eggs); in South Africa, Tongaland, from 36 to 44 mm, with a mean of about 42.1 mm (n = 26 clutches, 260 eggs); in Oman,
Masirah Island, from 38 to 46 mm, w ith a mean of 42.1 mm (n= 29 clutches); in Australia, Queensland, from 34.7 to 49.8 mm, w ith a mean of 40.4 mm
(n = 399 clutches, 3 990 eggs).
The nests o f these turtles som etim es contain undersized eggs, laid to g eth e r with the norm al ones, but never in such
large quantities as in the leatherback turtle; oversized and abnorm al-shaped eggs are also present, but not frequent.
Egg weight m easurements are less frequent than those o f diameter size, and available data range from 26.2 to 46.8 g.
Som e exam ples are the follow ing: USA, Florida, M erritt Islands, from 33.7 to 49.1 g, w ith a m ean o f 41.2 g (n =46 clutches, 5 666 eggs); M exico,
Q u inta na Roo, M ujeres Island, from 35.2 to 48.7 g .w ith a mean of 40.7 g (n = 23 clutches, 10 eggs per clutch); contin e n ta l beaches of the same state
the mean w as 36 g (n = 10 100 eggs); C olom bia, Buritaca River, from 29.7 to 46.8 g, w ith a mean o f 38.4 g (n = 3 clutches, 370 eggs); A ustralia,
Queensland, from 26.2 to 43.1 g, w ith a mean of 36.5 g (n = 24 clutches, 240 eggs); Japan, Hiwasa, from 30.5 to 32.8 g, with a mean of 31.8 g (n = 9
eggs w ith 9 days o f incubation). In general, the mean egg m ass varies from 36.5 to 41.2 g; the small eggs from Hiwasa w ere not used because o f the
nine days already elapsed after deposition and the reduced number of eggs in the sample.
The incubation period varies am ong populations and with beach latitude; e.g. USA, South Carolina, 55 to 62 days;
H utchinson Island, Florida, mean duration 68 days; M exico, Q uintana Roo, m ean duration 56 days; Turkey, 50 to 64
days, mean duration 57 days; Greece, Zakinthos Islands 49 to 69 days, mean duration 57 days; South Africa, Tongaland,
55 to 65 days, mean duration 68 days; Japan, Hiwasa, usually 58 days.In general, the warm est places and tim es result in
the shortest periods o f incubation, so there are differences on the same beaches depending on location o f the nest and
tim e o f oviposition; even in the same localities, the incubation length changes from season to season.
Size and w eight o f hatchlings are considered to be correlated directly w ith the size o f the eggs; the more frequent
m easurem ents are straight carapace length (SCL) which ranges from 33.5 to 55 mm, and total weight (range o f mean
v a lu e s from 18.8 to 21.1 g).
In USA, th e se m easurem ents vary from 33.5 to 50 mm in several sa m ple s from South Carolina, Georgia, Florida and T e xa s (n = 722), w ith an
a p p ro xim a te mean o f 45.3 mm and a mean w e ig h t o f 20.2 g (n=438); in M exico, fro m 38 to 50.5 mm , in several sam ples fro m Q u inta na Roo
(n = 185), w ith an a p p ro xim ate mean o f 45.3 mm and a mean w e ig h t o f 24.2 g (n= 100); in Colom bia, from 42.5 to 48 m m in tw o sam ples from
Buritaca River, with a mean of 45 mm and a mean w eight of 18.8 g (n = 46); in Greece, Zakinthos, a mean of 40 mm was obtained (n = 221); in Turkey,
from 37 to 42 mm. w ith a mean of 39.9 mm (n = 50); in South Africa, from 37 to 48.8 mm in several samples from Tongaland, w ith a mean of 43.7 mm
(n = 1824) and a mean o f 21.2 g (n =88); in A ustralia, from 39 to 49.6 mm in several sam ples from M on Repos-Bundaberg w ith a m ean o f 43.4 mm
(n = 837) and 20.7 g o f mean w e ig h t (n = 817); in the Solomon Islands, from 43 to 46 mm w ith a m ean o f 44.9 m m (n = 10); in Japan, from 43 to 55
mm, w ith a mean of 45.8 mm (n = 60) and a total weight of 24.2 g (n = no data).
Age at first m aturity has not been clearly determ ined yet. Data derivated from research in captivity indicate ages from
6 to 20 years; the back calculation from capture - recapture data o f tagged nesting females, analyzed through logistic
and von Bertalanffy growth curves, produce ranges from 12 to 30 or more years, for m inim um (74 cm) and m aximum
(92 cm) straight carapace lengths; these data apply to the southeastern coast o f the United States, but differences must
be expected for nesting beaches located on different latitudes, as Colom bia, Oman, Australia or Japan.
19
Unlike other sea turtles, courtship and m ating are usually not perform ed near or in front o f the nesting beaches, but
along the m igration routes betw een feeding and breeding grounds. C ourtship and m ating are not com m only
observed, but some photographs have been taken, e.g. the photograph by Mr Larry Bearse (Anon., 1985) south o f Cape
Hatteras in North Carolina, USA, on 28 March 1985, in w a te rs o f the w estern side o f the G u lf Stream . M ating
apparently is accom plished w hile floating on the w ater surface, but in Australia near Sandy Cape, Limpus (1985) has
reported underw ater copulation. In captivity, it is com m on for one fem ale to be covered several tim es by different
m ales before the nesting tim e, but other fem ales are covered by only one male before nesting, apparently w ithout any
effect on the fertility o f the eggs. It is also possible that through storage o f the sperm o f one or several m ales in the
reproductive tract (oviducts) o f the female, all clutches o f the current nesting season can be fertilized w ithout repeated
matings. Mating usually is performed several weeks before the nesting season.
O ptim al incubation o ccu rs w ithin a lim ited range o f tem peratures, usually betw een a m inim um o f 26°C and a
m aximum o f 32°C; there is evidence that sex determ ination is m ale-biased in cool tem peratures and that survival rate
decreases at the extrem e tem peratures o f this range. The “pivotal tem perature” , defined as the tem perature w here a
1: 1 sex ratio occurs, seem s to be about 30°C for this species, but it may show sm all variations am ong populations and
with geographical latitude. A s in all the other sea turtles, hatching occurs in the course o f several days (2 to 3); it takes
several hours for the hatchlings to reach the surface o f the sand and only a few m inutes to em erge from the nests.
Em ergence occurs m ostly at night; the peak tim e usually lies between 2 1 :00 and 02:00 hours, but during cloudy days it
may continue late in the m orning. A fte r the m ajority o f hatchlings appear at the surface o f the nest, they start a
frenzied race to the su rf and disappear in the waves. Highest predation occurs in the incubation period and during the
race o f the hatchlings to the sea. Small turtles swim straight out from the coastal shallow waters, since fish predation
decreases strongly in deep waters. Massive destruction o f eggs and em bryos is also caused by natural phenom ena such
as erosion or sea overwash. Eggs, em bryos and hatchlings are devoured by a great variety o f predators and prim arily or
secondarily affected by bacterial and fungal diseases. It is comm on that clutches o f eggs or hatchlings, w hile rem aining
in the nests, are eaten by ghost crabs, ants and fly larvae; predation by m onitor lizards ( Varanus) in South Africa and
Northern Australia, and by raccoons in some beaches o f Florida and South Carolina is responsible for over 40 and 56%
o f egg losses respectively; skunks, feral dogs, genets, pigs, foxes, jackals (in Cape Verde and Libya) also destroy nests.
During the synchronous nocturnal travel from the nest to the surf, hatchlings are devoured by m any o f the abovem entioned predators. Land and shore birds also take th e ir quota if hatchlings em erge in day tim e. A fter reaching the
waves, predation continues by marine birds and neritic and pelagic fishes (e.g., Centropristes, Coryphaena).
Little is known about predation on juve n ile s and adults, but they are usually too large for m any predators except the
big carnivorous fishes such as groupers, snappers and jacks. Sharks are the principal enem ies for all size classes o f
turtles. T urtles above m edium size are able to avoid shark attacks, by presenting the flat side o f the plastron or
carapace to prevent biting. The w o rst predator o f loggerhead tu rtle s is man who is able to take the entire egg
production o f any beach or capture any size and quantity o f turtles. The loggerhead turtle is the m ost prone to bear
epibiontic organism s, including leeches, crabs, green filam entous algae, etc. Leeches could be the cause o f skin damage
and secondary infection and also propitiate the tissue degeneration known as papillomae.
Feeding behaviour may change som ew hat with age, but this species is carnivorous throughout its life. There is evidence
that hatchlings o b ta in th e ir food from the fauna living in seagrass mats, frequently distributed along the drift lines and
eddies. Hatchling gut contents have shown jellyfishes, pieces o f Sargassum , gastropods (Diacria, Litiopa), crustacean
appendages and m aterials as grit, feathers, bark and plastic pieces. Juveniles, subadults and adults have been more
extensively studied and show a very wide variety o f prey, principally benthic fauna like, conchs (Strom bus, Cypraea,
Conus, K e lle tia , Cassis, Janthina, Harpa, etc), clam s (Cardium, Pecten, M actra, Pinna, Venus, etc.), horse shoe crab
(Lim ulus), crabs (Calappa, Callinectes, Portunus, Cancer, Hepatus, etc.), occasionally shrim ps (Pennaeus, Sicyonia), sea
urchins, sponges, fishes (B revoortia, Sardinops, Scomber, Diodon, etc.), squids, octopuses, and also m an-caught fauna
(shrim p-traw l bycatch). Because o f th e ir carnivorous diet (molluscs-crustaceans), loggerheads com pete for food with
ridley sea tu rtle s (Lepidochelys). During th e ir m igration through the open sea they eat jellyfishes, pteropods, floating
molluscs (Janthina), floating egg clusters, flying fishes, squids, lobsterets ( G alatheids). In western Baja California, many
o f the dissected loggerheads had full stom achs containing only Pleuroncodes p lan ipes (the pelagic small red lobsteret).
Som etim es the diet includes sea turtle hatchlings, floating algae (Sargassum ) and other plants, but it is suspected that
plant ingestion is involuntary during feeding activities. In a loggerhead from Trinidad and Tobago, the only species
found in the stom ach was Conus erm ius. Experim ents show that although this species has food preferences, it clearly is
a facultative feeder over a wide range o f food items.
S ize : In general, the mean straight carapace length (SCL) o f the m ature fem ales is between 81.5 and 105.3 cm
(n = 3502), with a mean weight near to 75 kg (65.7 to 101.4 kg, n = 153). The carapace length (SCL) in nesting fem ales
varies within a limited size range, but is always over 70 cm.
20
For example, in the USA, South Carolina, 84.4 to 103 cm, with a mean o f 92.7 cm (n = 18); Georgia, a mean o f 95.9 cm (n = 110); Florida, 74.9 to 109.2
cm with a mean o f 92 cm (n = 661), and Broward county, a mean o f 99.6 cm (n = 1203). In M exico, Q uintana Roo. 73 to 109 cm , with a mean o f 90.5
cm (n = 423) fo rfe m a le s, and 75.3 to 9 9 .5 cm, with a mean o f 86.5 cm (n = 39) fo r males. In Colombia, Buritaca, 70 to 102 cm, w ith a mean o f 87.9 cm
(n = 77). In A rgentina-U ruguay, M ar del Plata, a non-breeding population ranges from 50 to 115 cm (n = 61, both sexes). In Greece, Zakinthos Islands,
a mean o f 81.5 cm (n =95). In Senegal, a mean o f 105.3 cm (n = 3). In S outh A frica, Tongaland, from 72.8 to 98.5 cm , w ith a mean o f 86.4 cm
(n = 1 182); Natal, from 75.2 to 90.5 cm, with a mean o f 81.6 cm (n = 13). In Oman, Masirah Islands, a mean of 91.2 cm (n = 1 378). In Australia. Heron
Islands, from 86 to 102 cm. In Japan, Shikoku, from 72 to 107.5 cm , with a mean o f 89 cm (n = 118). Data on body m ass are less available. In Mexico,
Q uintana Roo, mean w eights o f fem ales are 65.7 kg (n= 115) and o f males, 101.4 kg (n =38); in the M editerranean region a mean o f 105 kg is
com m on; in South A frica, Ton g ala nd , th e m ean is 106.9 kg (n = 31) in fe m a le s and 68 kg (n = 13) in m ales.
Interest to Fisheries : Up to several years ago (the seventies), Caretta was com m only captured in com m ercial operations
and the meat, eggs, leather and fat were used. However, its flesh and leather is less valuable than that o f the green
turtle (Chelonia), and the carapace brings a low er price than that o f the hawksbill
turtle (Eretm ochelys), which
produces tortoise-shell. W ith few exceptions, in m any countries this species has not been the m ajor target in the sea
turtle catch; but in the northern and northeastern G u lf o f M exico, T exas and Florida, it w as captured as bycatch and
canned together with the green sea turtle up to the early fifties. On the eastern coast o f Mexico it w as captured jointly
with the green turtle, but w hile the loggerhead w as consum ed fresh, the green turtle w a s exported, principally to
Tam pa, Florida, up to late seventies. In Cuba, the exploitation continues, but at a restricted annual level o f between
250 and 300 m etric tons. It is very com m on that in places w here regulations are not strictly enforced, the eggs are
consum ed w h enever found and also w idely com m ercialized in unknown quantities, generally through illegal markets.
The m ost com m on w ay o f C aretta harvesting has been the “tu rtle tu rn in g ” on the beaches and the setting o f
entangling nets, the m ajority in front o f nesting beaches. In Caribbean shallow w aters, the nets used are made o f
cotton yarn with light w e ights on the bottom line, to avoid drowning the turtles, and sim ilar nets are used in the G ulf
o f M annar. The capture w ith nets is increased during the night tim e. Several kinds o f harpoons with detachable iron
points have been w idely used. H arpooning generally w as perform ed by two fisherm en on sm all w ooden boats, one of
them paddling and the other “h unting” at the bow o f the boat. In the transparent Caribbean w a te rs it is possible to
observe the tu rtle s on the bottom , so the tu rtle rs can follow the prey until it com es up to breathe. This m om ent is used
for harpooning it; this method is called “correteada” , - rove or boat-chase - on the W estern Caribbean coast o f Mexico.
The FAO Yearbook o f Fishery Statistics reports loggerhead catches only from Fishing Area 31 (W estern Central Atlantic,
Cuba only). The registered w orld catch w as 273 m etric tons in 1983, 277 m etric tons in 1984. 322 m etric tons in 1985,
309 m etric tons in 1986 and 238 m etric tons in 1987.
Because o f th e ir feeding behaviour and th e ir habit o f overw intering in shallow waters, this species, to g eth e r with
Lepidochelys, is more prone to capture by shrim p traw lers and gill-nets (m ainly shark-nets). In recent years, in Atlantic
w a te rs o f the USA, around 32 000 loggerheads were caught annually and nearly 21% o f them died by drowning; in
addition, m ore than 10 500 tu rtle s were trapped annually in the G u lf o f Mexico by the sam e typ e s o f gear, and
approxim ately 29.8% o f them were killed during traw ling. The m ajority were late juve n ile s and subadults, w hile adults
were relatively few. Also the records o f the “ Sea Turtle Stranding and Salvage N etw ork” from the east coast o f the
USA show that loggerhead turtles were the most frequently stranded (73%) o f the five A tlantic species, with a total of
2 373 individuals registered during 1987. The blasting o f old petroleum platform s is another cause o f high sea-turtle
m ortality, especially o f loggerheads. T his kind o f m ortality is also reported for M exico, Australia, South Africa, Japan,
China, and w h e re ve r the loggerhead lives. The extent o f the m ortality needs to be evaluated in all these and other
areas such as the Mediterranean Sea and the southern coast o f the Arabian Peninsula.
Local Species Nam es : ARABIAN PENINSULA, EGYPT, OMAN (Red Sea): Remani; AUS TR A LIA (Torres Strait): Maiwa;
BRAZIL: Avo de aruana, Tartaruga caret, Tartaruga m esticona, Vovo de tartaruga; CARIBBEAN REGION, COLOMBIA,
CUBA, GUATEM ALA, MEXICO, PANAMA, PERU, VENEZUELA: Caguama, Cahuama; CHILE, SPAIN: Boba; CHINA: Tsu-tsi;
CO LO M BIA: Coco, Tortuga gogo; FRANCE: Grosse tê te , Tortue caouanne; G ERM ANY: Unechte Karettschildkröte;
ISRAEL: Taras al asfar (Arabic); ITALY: T artaruga caretta, T artaruga com une;
INDIA (Tam il): Perunthalai amai;
INDO CHINA: Lemech; INDO NESIA: Penyu m angong; IRIAN JAYA: Marab, Penyu waukaku; JAPAN: Aka umi game;
M EXICO (Pacific)- Javalina, Perica; M O ZAM BIQUE: Lindi, N’duvi; PAPUA N EW GUINEA: Babam ukara, Guiguina, Lantuc,
M aiw a -g a m o, Mogobul, Nukali, Ponowan; PHILIPPINES: Pawikan; PORTUGAL: Tartaruga; SENEGAL: Tortue caouanne,
Tortue jaune; SEYCHELLES: Nam koyo. Torti batar; SOUTH AFRICA: Eluvi, llongosi; (Afrikaans: Kertseeskilpad); SRI
LANDK: Nai mai, Olu geddi kasdava; TH A ILA N D : Tao-ya; T U N ISIA: Fahroun
el bahr; UK, USA: Loggerhead;
V E N E Z U E L A : C a rdo n .
Literature : Pope (1935); Deraniyagala (1939); Kuriyan (1950); Carr (1952, 1986a.b. 1987); Caldwell, Carr & Hellier
(1955); Carranza (1956); Caldwell & Carr (1957); Loveridge & W illiam s (1957); C aldwell (1959, 1962, 1969); Schaefer
(1962); Achaval (1965); Bleakney (1965); Me Allister, Bass & van S choor (1965); Capocaccia (1966); Kauffm an (1966,
1971, 1972. 1975); Me Cann (1966); Hughes, Bass & M entis (1967); Hughes & M entis (1967); Nishim ura (1967); Kondo
(1968); Routa (1968); de Silva (1969); M arquez (1970, 1977); Bustard & Lim pus (1971); Brongersm a (1972, 1981); Ross
(1972, 1981); Bruno(1973); Hughes (1974, 1975, 1977, 1981); MC Gehee (1974); Rebel (1974); Schwartz (1974); W itham
(1974); Ogren, W atson Jr. & W ickm an (1977); Uchida (1977); Frazier (1979, 1984, 1985a,b); Hopkins, Murphy, Stansell &
W ilkinson (1979); Lazell (1979); Carr, Ogren & Me Vea (1980); Rodin, Springer & Pritchard (1980); Balazs (1981); de Silva
21
(1981); Geldiay, Koray & Balik (1981); Chu-C hien (1981); Orgen & Mc Vea (1981); Polunin S Sum ertha (1981); Pritchard
(1981); Ross & Barwani (1981); Sella (1981); Spring (1981); Suwelo, Sum ertha & Soetrisno (1981); Uchida & Nishiwaki
(1981); G rassm ari & O wens (1982); Hoffman & Fritts (1982); M endonca & Erhart (1982); Shoop & Ruckdeschel (1982);
W ickram singe (1982); Argano & Baldani (1983); Berry et al. (1983); Bjorndal & M eylan (1983); Frazier & Salas (1983,
1984); M aigret (1983, 1986); M argaritoulis (1983, 1985); M usick et al. (1983); O gren (1983); Fletem eyer (1984);
M artinez (1984); Pritchard & Trebbau (1984); Frazer & Erhart (1985); Lim pus & Reed (1985); Pascual (1985); Sutherland
(1985); Dupuy (1986); Ehrhart & W itherington (1986); Kam ezaki (1986); Kushlan (1986); M oreira & Benitez (1986);
V eniselos (1986); Zug, Hynn & Ruckdeschel (1986); Alfaro, Blain & M unoz (1987); Discovery Center (1987); Fretey
(1987); Hoffman & Conley (1987); M arquez & Bauchot (1987); Schleich (1987a,b); Dood (1988, pers com.); GilHernandez (1988); G ram entz (1988); M arquez & Fritts (1988); Senaris (1988); S chroeder & W arner (1988); Uchida &
Teruya (1988).
CHEL Chel
Chelonia Brongniart, 1800
Genus : Chelonia Brongniart, 1800, Bull. Soc. Philom ., Paris, 2:89.
Type Species : Testudo mydas Linnaeus, 1758, Syst. N at., Ed. 10, T. 1: 197
Synonym s : Chelonia Latreille, 1801; Chelone Brongniart, 1806; Chelonia s Rafinesque, 1814; Caretta (in part): Merrem.
1820; Chelona Burmeister, 1837; M ydas Cocteau, 1938; Euchelonia Tschudi, 1845; M egem ys Gistel, 1848; Euchelys
Girard, 1858; Chelone Strauch, 1862; Chelone Boulenger, 1889.
D iagnostic Features : M edium - to large-sized sea turtles; adults usually have
a carapace length (SCL) between 70 and 140 cm. Carapace profile generally
scutes. Head com paratively sm all and blunt (preorbital distance sm aller than
M andibles covered by a horny tom ium , with sharp cutting ridges, the lower
engages w ith the vertical ribbing on the inner surface o f the upper tom ium
with only one visible claw.
a body m ass between 50 and 200 kg and
oval in dorsal view, with 4 pairs o f lateral
orbital length), with two prefrontal scales.
ja w more strongly serrated; the serration
and becom es sm ooth with age. Flippers
Rem arks : This genus form erly included 3 species, but one o f them w as recently reviewed and renam ed as N a ta to r
depressus. Some authors recognize only one species, Ch. mydas, with two or three subspecies. The present author
recognizes two valid species, Ch. m ydas and Ch. agassizii, which are distinguished m ainly by the shape o f the carapace
w hich is subcardiform , narrow er and usually more strongly vaulted in Ch. agassizii, and by th e ir w e ll-delim ited
distribution areas (Eastern Pacific for Ch. agassizii and Atlantic, and Indo-Pacific for Ch. mydas).
Chelonia agassizii Bocourt, 1868 *
CHEL Chel 2
Chelonia agassizii Bocourt, 1868, Ann. Sei. Natur., Ser., 5, Z oo l., 10:121-122, 3 pi. (Guatemala, Nagualate river mouth).
Synonym s : Chelonia (Euchelonia) m idas Tsuchudi, 1845; Chelonia virgata Agassiz, 1857; Chelonia A gassizii: Duméril
& Bocourt, 1870; Chelonia lata Philippi, 1887; Chelonia virgata: Velasco, 1892; Chelonia agassizi: van Denburg, 1886;
Chelonia viridis Gadow, 1905; Chelonia ja p o n ic a Stephens, 1921; Chelonia m ydas ja p o n ic a : M ertens & Muller, 1928;
Chelonia mydas agassizii: Carr, 1952; Chelonia m ydas carrinegra Caldwell, 1962; Chelonia agassizi: Carr, 1967.
Subspecies : None.
FAO Species Names : En - Eastern Pacific green turtle; Fr - Tortue verte du Pacifique est; Sp - Tortuga prieta.
Diagnostic Features : This is the sm aller species o f the genus Chelonia. The carapace in adults is often strongly elevated
or vaulted, especially in large fem ales, but with a less round profile in frontal view than in C helonia mydas', in dorsal
view the carapace is subcardiform and slightly em arginate over the neck and fore flippers, and deeply em arginate over
the rear flippers. In subadults and young turtles, the last third o f the carapace usually has indentations between each
m arginal scute. The carapace w idth attains from 76 to 82% o f its straight-line length (SCL) and it becom es relatively
narrow er with age. The head is sm all and blunt, about 21.5% SCL. Carapacial scutes rather thin and sm ooth, usually 5
centrals, 4 pairs o f laterals, and 11 pairs o f m arginals. Ventrally, on the plastron, the scutes are less thick than those of
the carapace. Scute counts are the same as in Ch. mydas, a total o f 6 pairs plus 4 infram arginals at each side; there may
also be one in te rg u la r and one interanal scute. Head w ith usually one pair o f elongated prefrontal scales and 4
postorbital scales at each side (variable from 2 to 5). Tom ium o f low er jaw serrated, the serrations corresponding with
strong ridges on the inner surface o f the upper tom ium . Each flipper w ith a single visible claw at the outer border.
No illustration available. See Figs 26 and 27 for Ch mydas which is very sim ilar to Ch. agassizii
22
Colour : In dorsal, view, adults are characteristically dark. Carapace slate grey to black, with a blotched or radiating
brown and olive pattern, with or w ithout yellow radiating stripes; upper surfaces o f the head and flippers plain dark.
Plastron varying from w hitish grey to bluish or olive-grey. Young individuals are usually brighter and more colourful,
very sim ilar to those o f the A tlantic species. Some adult turtles have the carapace covered by a coat o f m icroscopic
green algae that give them a lustreless greenish colour; these tu rtle s are considered non-m igratory form s that
overw inter in the G ulf o f California, in a dorm ant status, over m eadow sites and are called locally “la to rtu g a echada”
(the flattened turtle). Several authors have described brightly coloured individuáis from the G alapagos Islands, which
they suggest are non-reproductive phases, because they have failed to find fem ales with ripe ovaries and enlarged
eggs. They call this variety “the ye llow ” and describe it as more fatty than the black one. Hatchlings, in general, have
colour patterns sim ilar to Ch. m y d a s : carapace and flippers dorsally very dark brown or black w ith a narrow white
border; ventrally white.
Geographical Distribution : The Eastern Pacific green turtle is
com m on along the w est coast o f Am erica, from central Baja ggo
California (C edros Island Scam m on Lagoon) and the G u lf o f
California, to southern Peru (Paracas Peninsula, Ilo); also on
islands like R evillagigedo and G alapagos (Fig. 25) Records
from outside these m ajor dw elling a re a s include British
Colum bia, Canada to Coquim bo, Chile, and there is even a 60°
report from Desolación Island (52° 5 1 ’S), the southernm ost
record for the species. The western range is uncertain; there
are reports o f m elanistic green sea turtles from Easter Island
and Hawaii. A possible intergradation with C helonia m ydas
{japonica variety ?), in these places and in the easternm ost
P olynesian Islands, needs to be cla rifie d and even the
? fl°
g eo gra p h ica l lim its for both these sp e cie s m ust ye t be iu
studied.
0°
H abitat and B iology : C helonia ag a s s izii inhabits coastal
w a te rs o f the eastern trop ica l Pacific O cean, and is not
commonly observed in the open ocean.
2®*
M igrations (shown by tag-recovery studies) occur between
the northern and so uthern extre m e s o f the distribu tio n
range as w ell as in regional patterns. T urtle s tagged at
nesting beaches o f M ichoacan, M exico, were recovered
northward and southw ard o f this point, as far as: Colom bia, 6o°
Panama, Costa Rica, El Salvador, G uatem ala and principally
Mexico, from the G u lf o f California and Bahia M agdalena on
the w estern side o f the Peninsula to the southern border
with G uatem ala. T urtles tagged on the G alapagos Islands
140*
120o
100°
80°
60°
C0°
20
Fig.25
were found principally eastward to the m ainland and from Costa Rica to Peru. The dispersion starts from the breeding
areas, ju st after the nesting season, and the destinations are the feeding grounds, but the exact routes followed are
unknown. The longest distance covered by Ch. aga s s izii w as 3 500 km (m easured along the coast and as straight as
possible), for a turtle tagged in M ichoacan, Mexico, on 1 Novem ber 1976 and recovered near Buena Ventura, Colombia,
after 266 days. The feeding grounds are not clearly delim ited, but some o f them are located on the w est coast o f Baja
California (Scam m on Lagoon, Tortugas Bay and M agdalena Bay), the G u lf o f California and the lagoons o f Oaxaca, in
M exico, the G ulf o f Fonseca (El Salvador) and the area between the G ulf o f Panama and southw est o f Colom bia, around
the G alapagos Islands (Punta Espinosa, Elizabeth Bay, Turtle Cove, Puerto Núñez, etc.),and o ff to Paracas Peninsula in
Peru.
Some o f the principal nesting grounds are located on the m ainland coast o f M ichoacan, M exico, on a dozen sandy
beaches such as: Colola, Maruata, Llorona, Kachan, Motin, Cuilala, La Tikla, Xicuasha, etc., all o f them covering more
than 25 km and separated by rocky cliffs. In Central Am erica there are several nesting points such as Jiquilisco in El
Salvador and several beaches in Guatem ala, w here also tag-recoveries o f M exican-tagged “black tu rtle s” come from.
O ther less im portant nesting sites are on islands, such as the Revillagigedo Archipelago, in Academ y Bay and Playas
Blancas on Clarion Island and in Sulfur Bay on Socorro Island. In the southern part o f the range, nesting occurs in the
Galapagos Archipelago: Quinta Playa and Barahona Bay on Isabel Island, Las Bachas on Santa Cruz Island, Las Salinas on
Baltra Island, Bartolome on Bartolome Island, Espum illa on Santiago Island and Playa Sardina on San Cristobal Island.
In addition to these breeding grounds, solitary nesting occurs throughout the range o f distribution, w herever a nesting
beach seem s suitable. This solitary nesting is reported from Jalisco, Mexico to Manta, Ecuador. The existence o f a
historical nesting ground w a s reported about 25 years ago, between the Paracas Peninsula and Ilo Port, in Peru
(Estremadoyro, pers. corn.).
23
The nesting season sh ifts in tim e, with the latitudinal position o f the rookery; th u s in M ichoacan, it extends from
A ugust to January, with the peak in O ctober-Novem ber; on the Revillagigedo Islands it is between March and July, and
in the G alapagos Islands, from D ecem ber to June, w ith the peak in February-M arch. On beaches shared with other
turtle species, the breeding o f Ch. ag assizii usually occurs after the peak o f the olive ridley, L. olivacea, and before that
o f the leatherback, D. coriacea, a behaviour which shows a clear adaptation in time and also in space; the Pacific green
is the species that nests at a greater distance from the high tide line than the other two, w hile the leatherback is the
one with the shortest distance. Such differences in time and space allow the use o f the same nesting beaches by various
species without disturbing their life-cycles.
The nesting cycle show s differences between northern and southern populations. In M ichoacan each fem ale may
produce from 1 to 8 nests each season, with an average o f about 2.8 nests per female, and a periodicity o f nearly 14
days between successive nestings; this turtle nests every 1,2 or 3 years, with a mean pattern o f 2.2 years for the overall
population; the mean size per clutch is about 70 eggs, with 38 to 139 eggs as a m inimum and m aximum for viable
clutches. In the south, on the G alapagos Islands, each female produces 1 to 5 clutches per season, with an average per
female o f about 1.4 nests, between periods o f nearly the same duration (14.3 days). The fem ales return to nest in cycles
o f 2 to 5 years (average 3.5 years) and the mean size o f clutches is around 81 eggs, with a m inim um o f 56 and a
maximum o f 152 units per clutch.
In Mexico, the size o f the eggs is sligthly correlated with age and size o f the turtle, as is also the case with fecundity.
C onsequently, young and sm all turtles lay few er and sm aller eggs. The minimum and maximum diam eters o f 70 eggs
m easured were 36.9 and 48 mm, w ith an average o f 41.6 mm; egg m asses o f 67 eggs w eighed from 35 to 46 g, with a
mean o f 39.6 g. The average size and weight o f 101 hatchlings were very sim ilar to those o f Ch. mydas, 46.6 mm o f
carapace length ano 21.8 g o f total weight.
The incubation period varies with latitude and tim e o f the season, from a m inim um o f 46 to a m aximum o f 62 days, in
warm and cool w eather respectively, com m only it is 50 to 55 days. A fter pipping the egg shell, the hatchlings remain in
the nest until the entire clutch is ready; during the night, suddenly all o f them emerge to the surface. If the w eather is
cloudy or cool, em ergence o f the hatchlings may be prolonged into the morning. This behaviour is com m on to all sea
turtles, as is also the hatchling’s way o f approaching the su rf zone, as described for Chelonia mydas.
The mean size at first m aturity changes every season, within a limited range; generalized data put it at about 68 cm o f
straight line carapace length. The age at first m aturity is uncertain; some authors assum e it to be 8 to 9 years, but it is
necessary to clarify this parameter on the basis o f more reliable data.
Nest site fixity is strong, and studies carried out on the G alapagos Islands show that 88% o f the tu rtle s nesting at a
particular beach had also nested at the same beach in the previous season. O f 12 turtles tagged at M ichoacan (1985) 11
had nested at the same beach in the previous season, and the twelfth nested on another beach (7 km away). In this
s p e c ie s , s u b s e q u e n t n e stin g in th e sam e se a so n a lso sh o w s high site fid e lity .
C ourtship is more rem arkable in this species than in other sea turtles; unpublished observations made by Cliffton,
Villanueva and the present author in the years 1976-79, o ff Colola and M aruata nesting beaches, showed that mating
pairs usually were escorted by up to a dozen additional male suitors, who som etim es nibbled the m aiting pair. Mating
pairs were more com m on in the neighbourhood o f the nesting beaches, especially during the first hours o f the day;
and it w as not uncom m on that a m ating pair came stranding ju st to the breakers. As a result o f recent m ale-biassed
com m ercial capture, the observation o f male suitors is now rare. Aerial surveys by Cliffton (1983) observed an average
o f only 1.04 male suitors per m ating pair. In M ichoacan, the breeding season begins with the approach o f the pairs to
the nesting beaches, around July or A ugust and m ating is observed nearly thro u g h o u t the season (August to
December) with a peak at its beginning; the peak o f the nesting activity is in September and October.
Predation is sim ilar to that o f Ch. mydas. Eggs are eaten by skunks (in M ichoacan) or boars (in Galapagos) or dom estic
and feral dogs, pigs, ghost crabs, ants, a kind o f burrowing beetle, Trox suberosus (in Galapagos) and other predators.
A scavenger fly (Sarcophagidae), that usually infests the entire clutch at any tim e o f the incubation, causes a high
m ortality to the hatchlings in M ichaocan, ju st before they leave the nest. A high predation rate occurs at the pipping
tim e, w hen the nests release an odour easily detected by pigs and dogs, or any other predators. The crabs invade the
nests through holes or capture the hatchlings w hen they cross over the beach to the w ater, a m om ent in which these
are also predated upon by shore birds. In the Revillagigedo Islands (Mexico), a racer snake (M asticophis anthonyi) eats
hatchlings o f sea turtles. In the w ater, sea birds continue the predation, to g eth e r with pelagic fishes o f the fam ilies
Carangidae and Scom bridae, and a needlefish (Thylosurus) has been seen in the m om ent o f capturing new hatchlings
in front o f the M ichoacan’s nesting beach; at this tim e, also sharks maraud the beaches. Predation continues all along
the life-cycle, specially by carnivore bony fishes and sharks. In M ichoacan it w a s com m on to observe, during the
seventies, carcasses o f fem ales on the beaches that had been attacked by dogs while they were laying; the attack
usually w as perform ed at first by the bitch that w as followed by a pack o f hounds.
T his kind o f predation is less
comm on today because o f protection m easures im plemented in turtle camps.
24
The food o f adults o f Chelonia aga s s izii includes a num ber o f species o f algae; the diet varies between the feeding
grounds, for exam ple: M acrocystis in Peru, Z ostera and G igartina in Chile, Caulerpa in G alapagos, Sargassum ,
G raciiiaria, R hodim enia and G elidium in the G u lf o f California. Besides these food items, other species are consum ed in
variable quantities and occasionally the stom ach is full o f only one o f them, e.g.: G rateloupia, Laurentia, Griffitsia,
Liagora, Ulva, etc. In addition to m angrove shoots and algae, many species o f animals, including m olluscs (M ytilus,
Nassarius, Janthina), sponges, jellyfishes, annelids, and several kinds o f fishes and th e ir eggs are eaten by the turtles,
possibly during th e ir travel to and between feeding and breeding grounds. In a sam ple o f 19 tu rtle s from Bahia de Ios
Angeles, G u lf o f C alifornia, an average o f 1 230 cm 3 o f food per individual w as obtained, com posed o f 90% o f algae,
1% o f anim al food, and 9% o f unidentified m aterial; som e o f the plant sp ecies found were: G raciiiaria (19.5% ),
R hodim enia (13%), Gelidium (12.2%), G rateloupia (1.6%). Gigartina and Griffitsia (1.1%) (Rhodophyceae); Sargassum
(21%) and Padina (I .3%) (Phaeophyceae); Ulva (3.4% ) and C ladophora (1.3% ) (Chlorophyceae); anim al food included
m inor quantities o f sm all m olluscs, crustaceans, bryozoans, sponges, je llyfishes and echinoderm s. Another study made
w ith 9 adults on the central western coast o f Mexico, showed sim ilar results, but the most abundant alga w as Ulva, and
there w as also a larger variety o f anim al food. One turtle from that sam ple with a stom ach content o f 200 cm 3 had
consum ed exclusively the pelagic tunicate Pyrosom a (Urochordata). The feeding behaviour o f hatchlings and juveniles
is unknown.
Size : In the rookeries o f Mexico, the adult mean size for nesting fem ales is over 72 cm (CCL - over the carapace curve),
while the minimum and maximum values are 65 and 117 cm (CCL) respectively. On the G alapagos Islands, the CCL is 74
to 100 cm, w ith a mean o f 80 cm; the m ales are hence sm alle r than the fem ales. On the feeding grounds, the
individual size show s greater variations. In the G ulf o f California, the CCL in fem ales ranges from 59 to 107 cm, with a
m ean o f 74.6 cm (n = 171) and in males, from 60 to 99 cm, with a mean o f 80.9 cm (n = 49). Hence, unlike in the
rookeries, the mean size o f m ales on the feeding grounds appears to be greater than that o f females. The body mass
per individual (including juveniles, subadults and adults) in the G u lf o f California ranges from 3.5 to 126 kg w ith a
mean o f 39 kg (n = 335). In general, m ales are lighter than fem ales, but on the feeding grounds, the weight averages
are inverted, so that, at the same size, m ales are heavier than fem ales (55.8 and 41.6 kg respectively); possibly this is
due to the fact that the fem ales, w hile in the G u lf o f California, never have ripe gonads; it may also be a result o f a
d iffe re n tia l s e x -re la te d d is trib u tio n .
Interest to Fisheries : This species is the object o f im portant subsistence fisheries throughout its distribution, from
Mexico to Peru. The eastern tropical Pacific Ocean corresponds to FAO Fishing Areas 77 and 87, for which only general
statistics for marine tu rtle s are reported, w ithout a breakdown to species (total catch in 1987, 864 m etric tons for Area
77, and 305 m etric tons for Area 87). However, more than 90% o f the total turtle catch in these areas corresponds to
the olive ridley, Lepidochelys olivacea. No official catch statistics for this species are available for any country o f the
area. International com m erce is forbidden throughout its range o f distribution by the signatory countries o f the CITES
regulations.
Together w ith its A tlantic congener Chelonia mydas, the Eastern Pacific green turtle w as the m ost valuable am ong
m arine reptiles. For a long tim e it provided an abundant and easily available source o f food for the coastal inhabitants
o f Baja California. Historically, this species has supplied food for coastal Indian tribes, the Seris in the G ulf o f California,
the Pom aros in M ichoacan and the Huaves in Oaxaca, Mexico. In Baja California, Sonora and Oaxaca, the tu rtle s were
captured for their meat, but in M ichoacan only the eggs were harvested. In the 19th century, passing ships, particularly
whalers, were supplied w ith fresh m eat from th is abundant resource. Early in this century, about 1 000 turtles per
m onth w ere shipped from Baja C alifornia (M agdalena Bay, S cam m on’s Lagoon, Tortugas Bay, and Bahia de Ios
A ngeles) to San Diego and San Francisco, California, USA; turtle export declined during the 1940’s and 1950’s but
continued up to the 1960’s. In the m iddle o f the seventies, a kind o f “dorm ant or o ve rw inte rin g ” green turtle was
discovered resting over the seaweed m eadows in shallow w aters o f the central part o f the G u lf o f California. Shorthly
afterw ards, th is population w as decim ated by scuba divers. A n o th e r dw elling area for the sp ecies lies in the
neighbourhood o f the Tehuantepec Isthm us and in the coastal lagoons o f this zone; here ju veniles and subadults are
c o m m o n ly fo u n d in th e tu rtle fis h e ry p ra c tis e d by th e H uave In d ia ns.
In M ichoacan, M exico, poaching o f eggs w as very com m on up to the seventies. In the 1960’s, hatchlings from the
Revillagigedo Islands were sold to pet shops in California, USA. Hatchlings are often collected by people as souvenirs
w herever they see them , and they are sold to tourists on several beaches o f the G alapagos Islands and on the mainland
in M exico.
This species appears to be com m on but transient in Central Am erica, and its capture usually is a bycatch o f the olive
ridley fishery as it also occurs on the feeding grounds o ff Colom bia and southern Panama; but on the m ainland o f
Ecuador and futher south it form s sm all fisheries, specially near the Paracas Peninsula, in Peru. T hroughout its range o f
distribution, the Eastern Pacific green turtle is accidentally captured during shrim p trawling or entangled in shark nets.
Nowadays, com m ercial exp lo ita tion is prohibited, but ten ye a rs ago the sp ecies w a s captured p rincipally with
harpoons, spears, entangling nets, by “ju m ping ” and also when they came to nest (actually this is the m ore com m on
25
practice o f poaching adults). For the fishery, m otorized boats, averaging 20 feet long, were used. In M exico, Ch.
agassizii w as captured as a “bycatch” o f the L. olivacea fishery. But in M ichoacan, during several years in the seventies,
quotas o f up to 200 male turtles per month were allowed between O ctober and May or June, and used exclusively for
Indian com m unities. T oday unregistered capture and poaching are the more com m on practices o f exploitation
throughout its geographical range. The fishing grounds correspond with the nesting and feeding grounds m entioned
above. Fishing is practised throughout the year, with peaks during the breeding season, which extends from the end o f
s u m m e r to th e end o f a u tum n .
Local Nam es : COLOMBIA, CHILE, EL SALVADOR,
ECUADOR: Tortuga prieta; G UATEM ALA: Parlama,
Caguama prieta, Parlama, Sacacillo, Tortuga negra
T o rtu g a c o m e s tib le ; USA: B la ck tu rtle , E ast P a c ific
PANAM A and PERU: Tortuga Verde; COSTA RICA: Tortuga negra;
Tortuga negra, Tortuga Verde; HONDURAS: G uiltora; M EXICO:
and Tortuga prieta; NICARAG UA: Torita; PERU: Tortuga blanca,
g re e n tu rtle .
Literature : G arm an (1880); van Denburg (1922); Stejneger (1943); Yanez (1951); Peters (1954); Battstrom (1955);
Caldwell (1962, 1962a. 1963, 1969); D onoso-B arros (1966); Nelson (1966); M arquez (1970); Pritchard (1971, 1971a);
M arquez & Doi (1973); Casas-Andreu & G om ez-Aguirre (1980); Nat. Fish. & W ildlife Lab. (1980); Fritts (1981); Green &
O rtiz-C respo (1981); Hays-Brown (1981); Hurtado, C orrales & Fuentes (1981); M arquez et al. (1981); M ortim er (1981);
Groom bridge (1982); Frazier & Salas (1982); Cliffton & Cornejo (1983); Hurtado (1984); Alvarado, Figueroa & Gallardo
(1 9 8 5 ); A lv a ra d o & F igu e ro a (1 9 8 6 ); H e n d rickso n (p e rs .co rn .).
Chelonia mydas (Linnaeus, 1758)
Figs 26, 27
CHEL Chel 1
Testudo mydas Linnaeus, 1758, S ystem a N a tu ra e , Ed. 10, T. 1: 197 (A sce n sio n Island).
S y n o n y m s : Testudo m acropus W albaum , 1782; Testudo viridis Schneider, 1783; Testudo ja p o n ic a Thunberg, 1787;
Testudo M arina Vulgaris Lacepède, 1788; Testudo viridi-squam osa Lacepède, 1788; Testudo chloronotus Bechstein,
1800; Chelonia m ydas: Brongniart, 1800; Testudo cepediana Daudin, 1802; Testudo rugosa Daudin, 1802; Chelonia
m idas (sic): Shaw, 1802; C helone m y d a s: Brongniart, 1805; Chelonia m yd as: Schweigger, 1812; Chelonia virgata
Schweigger, 1812; Caretta Cepedii Merrem, 1820; Caretta esculenta Merrem, 1820; Caretta nasicornis Merrem, 1820;
C aretta T hunbergii M errem, 1820; C aretta M y d a s : Fitzinger, 1826; Chelonia m acu losa Cuvier, 1829; Chelonia
lachrym ata Cuvier, 1829; Chelonia M idas (sic): W agler, 1830; Chelonia m ydas (var.) ja p o n ic a : Gray, 1831; Chelonia
esculenta W eigm ann & Ruthe, 1832; Chelonia bicarinata Lesson, 1834: Chelonia virid is: Tem m inck & Schlegel, 1834;
Chelonia M arm orata Duméril & Bibron, 1835; Chelonia (Chelonia) M yd as: Fitzinger, 1836; Chelonia (M ydas) virid is:
Cocteau, 1838; Chelonia (M ydas) virg ata: Cocteau, 1838; Chelonia (M ydasea) m ydas: Gervais, 1843; Chelonia viridis:
Gray, 1844; M egem ys m ydas: Gistel, 1848; Chelonia m yd as: Agassiz, 1857; Chelonia form osa Girard, 1858; Euchelys
m acropus Girard, 1858; Chelonia tenuis Girard. 1858; Chelone m acrop us: Strauch, 1862; Chelone v irg ata: Strauch,
1862; Chelone m aculosa Strauch, 1862; Chelone marmorata'. Strauch, 1862; Chelone a lbiventer Nardo, 1864; Chelone
virid is: Strauch, 1865; Thalassiochelys albiventer. Gunther, 1865; M ydas virid is: Gray, 1870; Chelone m idas (sic):
Cope, 1871; C helone m y d a s: Boulenger, 1889; Chelonia m ydas m yd as: M ertens & M uller, 1928; Chelonia m ydas
ja p o n ic a '. M e rte n s & M u lle r, 1928.
Subspecies : These are not clearly defined. Apparently, Chelonia mydas has at least two subspecies, separated mainly
by th e ir geographical d istribution ranges and by som e m orphological and behavioural features, that need to be
further elucidated. The Pacific subspecies com plex is more difficult to define in the overlapping distribution areas o ff
South Africa and O ceania, and possibly there is intergradation between the Central Pacific population o f Chelonia
mydas and the Eastern Pacific species, Chelonia agassizii. The position adopted by the author is that Chelonia mydas
com prises two subspecies: Ch. m. mydas (Linnaeus, 1758) for the tropical and subtropical A tlantic Ocean and Ch. m.
japonica (Thunberg, 1787) for the tropical and subtropical Indian and the W estern and Central Pacific oceans. The
e a s te rn P a c ific b o u n d a ry o f th e s u b s p e c ie s ja p o n ic a is u n c e rta in .
26
FAO Names : En - Green sea turtle; Fr -Tortue verte; Sp - Tortuga blanca.
-,
V
/ -W i W
Fig. 26
D iagn ostic Features : Body depressed in adults,
carapace oval in dorsal view, its width about 88% o f its
length. Head relatively sm all and blunt, about 20% o f
the carapace length; one pair o f elongated prefrontal
scales betw een the orbits; tom ium o f low er ja w with
a sharply serrated, cutting rim that corresponds with
s trong rid ge s on the in n e r surface o f the upper
to m iu m , w h ich lo se s its tip cusp w ith age. The
carapacial scutes are thin, sm ooth and flexible when
rem oved. Those o f the dorsal side include 4 pairs o f
la te ra l
scu te s,
the
fo re m o st
not to u ch in g
the
p recentral scute; 5 central scutes, low -keeled in
juveniles, but lacking a m edian keel in subadults and
adults; and usually 12 pairs o f m arginal scutes. On the
underside, the scutes are also sm ooth and rather thin
and com prise 4 pairs o f infram arginal, 12 pairs o f
central plastral, usually one intergular and som etim es
one interanal scute. Each flipper has a single, visible
claw . C o lou r: On the u p p er side, the g e n era l
appearance v a rie s from pale to very dark and from
plain colour to brilliant com binations o f yellow , brown
and g reenish tones, form ing radiated stripes, or
abundantly splattered with dark blotches. The Pacific
po p ulatio n s are more m elan istic than the A tla n tic
ones. In juveniles, the scales o f the head and upper
sides o f the flip p e rs are fringed by a narrow, clear,
yellow ish m argin that is lost w ith age. Underneath,
the A tla n tic fo rm s are plain w hite, dirty w h ite or
ye llo w ish w hite; the Pacific form s are a dark greybluish-green, The newborn hatchlings are dark brown
or nearly black on the upper side, the carapace and
the rear e dges o f the flip p e rs w ith a w hite m argin.
U n d e rn e a th th e y are w h ite .
G eog rap hical D istribu tio n
W idely distribu te d in
tro p ic a l and su b tro p ica l w aters,
near co n tin en ta l
coasts and around islands, rare in tem perate w aters
(Fig. 28). T ogether w ith the haw ksbill (E retm och elys),
'
p re fro n ta l
s c a le s
p re c e n tra l
sc u te
low er ja w
1 c la w
c e n tra l
s c u te s
4 la te ra l
s c u te s
m a rg in a l
s c u te s
4 in fra m a rg in a l
s c u te s
p re fro n ta l s c a le s
fro n ta l
's c a le
dorsal view of head
plastron
Fig. 27
27
the green turtle is the most tropical o f the m arine turtles. Its norm al latitudinal range rem ains w ithin the northern and
southern lim its o f the 20°C isotherm s, and follow s the seasonal latitudinal changes o f these lim its. In sum m er, the
lim its are about 40°N and 35°S on the w estern sides o f the oceans, and som ew hat more contracted (to 30°N and 25°S)
on the eastern sides. During winter, they descend to 30°N and 25°S or less in the w estern sides, and to 20°N and 15°S
or less in the eastern sides. O ccasionally, some tu rtle s overw inter outside the above-m entioned latitudinal limits, as in
Chesapeake Bay on the east coast o f the USA. Also outside the norm al range there are m any records o f solitary
individuals, all o f them in non-reproductive stages. These stragglers reach higher latitudes in the north than in the
so u th.
Habitat and B iology : Ch. m ydas is a typical solitary nektonic anim al that occasionally form s feeding aggregations in
shallow w a te r areas with abundant seagrasses or algae. This species m igrates from rookeries to feeding grounds,
w hich are som etim es several thousand kilom eters away. Nearly all m igrations are perform ed along the coasts, but
some populations, e.g. those at Ascension Island, carry out transoceanic m igrations o f more than 2 200 km from this
island, w here they nest, to the coast o f Brazil w here the feeding grounds are located (Carr, 1962, 1975). The m ajor
nesting grounds are alw ays found in places with seaw ater tem peratures m ainly over 25°C. The most im portant nesting
beaches for the A tla n tic population are as follows: T ortuguero, Costa Rica and A ves Island, Venezuela; Bigisanti,
Eilanti and Baboensanti, Suriname; several beaches from Para to Sergipe, in Brazil; A scension Island and Cape Verde
Islands. In the M editerranean Sea, sm all colonies nest in several beaches o ff the southern coast o f Turkey: M ersin, Side,
Belek. and also on Cyprus Island, w here single nestings occur on the eastern coast. In the W estern Indian Ocean,
nesting occurs at Europa Island, the Com oro Islands (Moheli), Seychelles, Trom elin and M ascarenes Islands; Dem ocratic
Republic o f Yem en (Mukalla, Shihr); northeast o f Oman and M asira Island. In the W estern Pacific Ocean, nests have
been recorded from the southeast coast o f M alaysia and offshore islands; Sarawak, Satang and Talang Islands;
P hilippines (“Turtle Islands” ,the Sulu Sea, Pulau Boaan, Baguan, Taganak, Bakkungan, Palawan); Australia (Lacepède
Islands); G ulf o f C arpentaria, Rayne Island, Pandora Cay, Capricorn Group, including Heron Islands and Bunker Group
with Hoskyn Island. In the Central Pacific, nesting occurs on hundreds o f islands, but there is no com prehensive study
th a t co u ld sh o w th e ir s ta tu s and the s p e c ific b o u n d a rie s o f th e p o p u la tio n s .
80»
60«
20 °
■
20 °
60«
60«
40«
20«
20«
40°
60«
80»
100«
Fig. 28
Because o f the wide distributional range o f the species, the nesting season varies in tim e am ong distant and near
localities. The available inform ation on nesting seasons is very disperse, and two or more authors often quote different
periods for the same localities. Such inform ation m akes it more difficult to prepare com prehensive nesting calendars
by latitudes; hence, the available data are here com piled by geographical areas, e.g.: Caribbean Sea, from April to
O ctober, w ith the peak between June and S eptem ber (Belize, Caym an Islands, Cuba, T ortuguero - Costa Rica).
N orthwestern A tlantic Ocean, from May to October, with the peak between June and A ugust (eastern Florida). G u lf o f
M exico, from May to Septem ber, with a peak between June and A ugust (Tam aulipar, Cam peche, Y ucatan and
28
Quintana Roo). Southwestern A tlantic Ocean, throughout the year, with peaks from March to Septem ber (April - May in
Surinam, July - A ugust in French Guiana and Septem ber in Colom bia). Southeastern A tlantic Ocean, from Novem ber to
February (G ulf o f Guinea) and February - April (Ascension Island). W estern Indian Ocean, throughout the year, with
peaks from February to April (Aldabra Islands), from May to A ugust (Seychelles, Com oro A rchipelago) and from
Novem ber to February (Reunion and Eparses Islands). N orthwestern Indian Ocean, from May to O ctober beginning in
Saudi Arabia, and onw ards from A ugust in Oman and M asira Island. Central Indian Ocean, from July to March, starting
in southeast India and ending in the M aldive and Laccadive Islands. Eastern Indian Ocean, with a very long season, and
several peaks, from M ay to A ugust (Andam an - N icobar Islands, Thailand and W estern M alaysia), from June to
N ovem ber (Burm a). W estern Pacific O cean, th ro u g h o u t the year, w ith peaks from Novem ber to A pril (W estern
Indonesia); from March to Septem ber (Southern Japan, in June to July; China, Philippines and Papua New Guinea, in
July - August) and from Septem ber to April (Sabah, Palau, Bism ark Archipelago, Turks Islands). Central Pacific Ocean,
throughout the year, with peaks from Septem ber to February (New Caledonia, New Flebrides, Tonga, Samoa, Tokelau
Islands), from June to A ugust (M arshall Islands), from Novem ber to February (northern and northeastern Australia),
from June to A ugust (Hawaii - French Frigate Shoals) and from Septem ber to Decem ber (Society, Tuam otu and French
P o ly n e s ia Is la n d s).
Fem ales usually show nesting site fixity, and they are able to return to lay eggs near the same spot w here they left the
last clutch or even on the same beach from which they em erged as hatchlings. The interval between successive seasonal
nesting m ig ra tio n s depends on population, feeding ground quality and rem oteness. Usually there is a tw o -ye a r
breeding interval, but the tu rtle s may breed in cycles o f one, 3 or 4 years, or switch from one to another cycle, as a result
o f ageing or external influences (food quality and quantity). The successive nestings w ithin the same season are
separated by intervals o f about two weeks. The m ajority o f green turtles lay between 2 and 5 clutches, others lay only
once or more than 5 tim es, the average o f the colony, during the season, being usually slightly over 2.5 tim es per
fem ale. The mean clutch size ranges from 84.6 eggs (in the Solom on Islands) to 144.4 eggs (in southeast Africa). This
quantity also varies with age and size o f the turtle, tim e o f the season, distance o f m igration, etc.; the m inim um and
m axim um records are 38 and 195 eggs per clutch, in South Yem en and Ascension Island respectively. M inim um and
m aximum egg sizes recorded are 38 and 58.7 mm, with averages o f 42.3 and 54.6 mm (South Yem en and Ascension
Island respectively); the m inim um and m axim um weight records for egg m asses are 38.1 and 60.4 g (Southeast Africa
and A ustralia respectively), w ith averages o f 47.7 and 52.9 g (S outheast Africa and Com oro Island respectively).
Hatchlings also show variations in size and weight am ong populations; the records for carapace length are between 44
and 59 mm, with mean lengths o f 46.9 and 54 mm (South Yem en and Northeast Australia); the m inimum and maximum
body w eight records are 18.4 and 35 g (Southeast Africa and Hawaii) and the averages are 21.6 to 31 g (Comoros, French
P o ly n e s ia and H a w a ii).
There are m any speculations about the age at first m aturity. It has been estim ated as low as 6 years by some authors,
and between 8 and 13 or more years, by others. New studies using the average instead o f the sm allest sizes o f nesting
turtles, have produced estim ates ranging between 25 and 30 or more years (Florida, Flawaii and Australia). O f course,
the size and age at which the sexual m aturity is reached, show variations am ong individuals o f the same population,
and the differences are more rem arkable when com paring isolated populations. In captivity, green turtles reach 35 kg
in about 3 ye a rs (C aym an T urtle Farm, on Caym an Islands) and sta rt to reproduce in less than 10 years.
Reproduction involves courtship, copulation and nesting. A single fem ale, usually near shore, is courted by several
males; copulation begins early in the breeding season and stops when nesting begins; usually the fem ales avoid m ating
after they have laid the first clutch. It is hypothesized that fertilization o f the eggs laid in any nesting season takes place
several years before, and that the last “encounter” between m ales and fem ales probably serves to fertilize eggs for the
next season. New studies with turtles in captivity show that fertilization occurs early in the season and that excess sperm
is probably stored and used in the fertilization o f later clutches, and there may even be enough sperm for some clutches
o f the next season. A pparently there are no variations am ong hatch rates o f successive clutches w ithin a season, but
c e rta in ly som e fe m a le s have h ig h e r o r lo w e r ra te s o f fe rtility , and a fe w are in fe rtile .
Egg incubation on the sand beach norm ally extends from 48 to 70 days; the duration o f the incubation is related to
tem perature and hum idity which change in the course o f the season; hence it w ill be longer in cool w eather conditions.
Flatching and em ergence occur m ostly at night and stop when the sand becom es hot. The hatchlings em erge from the
nest sim ultaneously, race quickly to the s u rf and swim frenziedly tow ard the open sea. The colour o f the hatchlings,
black above and w hite below, is probably an adaptation to nektonic life at the w a te r surface and m akes the turtle less
c o n s p ic u o u s to fish and bird p re d a to rs.
There is high predation throughout the life-cycle o f green turtles, the eggs are consum ed by m am m als such as raccoons,
skunks, opossum s, m ongooses, coatis, dom estic pigs, dogs and also jaguars, and by oth er anim als like the m onitor
liz a rd s (Varanus), ghost crabs, ants, fly m aggots, etc. Some hatchlings are invaded by ants, m aggots and m ites
im m ediatly after, they pip the egg-shells, or by crabs, m am m als and birds, w hen they reach the nest surface; in the
w ater, the main predators are sea birds and carnivorous fishes,e.g., hatchlings were recovered from the stom achs o f a
29
dolphin fish (Coryphaena hippurus), and from groupers (Epinephelus (Prom icrops) lanceolatus) which are capable o f
devouring entire juvenile green turtles in the South Pacific. This predation continues until the turtle reaches a size big
enough to avoid being sw allowed. Sharks are the most form idable enem y throughout the life-cycle o f green turtles. In
the sea, invertebrates such as leaches (O zobranchius branchiatus and O. m arggoi), invade the epithelial areas o f the
body, especially near to the cloacal opening, eyes, axils, etc. causing necrosis, and it is reported that heavy infestations
can p ro d u c e a kind o f p a p illo m a to s is .
T his species, and the black turtle ( C helonia agassizii), in adulthood, are the only herbivorous sea turtles, but in
captivity, both can be m aintained on a carnivorous diet. Feeding behaviour in the young stages, from hatchlings until
juvenile size, is nearly unknown, but it is assum ed that they are carnivorous - which ensures them fast growth rates and when they get enough weight and size to avoid most predators, they progressively shift to a herbivorous diet. The
m echanism s and tim e required to becom e strictly herbivorous are unknown, but for exam ple, in all o f the
18 green
tu rtle s o f 7.8 to 54.5 kg studied in M osquito Lagoon, Florida, seagrasses (Syringodium , D ip lan tera and H alophila)
made up 86.5% +/- 10.6 o f the w et biom ass o f the stom ach contents; also, the stom ach contents o f 94 green turtles
between 31 and 120 cm o f carapace length from the com m ercial catch o ff the coast o f Ceara, Brazil (1965-67), included
from 88.3% to 95.5% o f bentic algae, and the rem ainder w as made up o f sm all quantities o f phanerogam s, sponges,
b ry o z o a n s , c ru s ta c e a n s , sea
u rch in s,
m o llu s c s and sea s q u irts .
Green tu rtle s feed during day-tim e in the seagrass beds that grow in shallow waters. These feeding grounds are
apparently not much used by other vertebrates, except for sirenians, but usually these m am m als and the green turtles
have m inimal overlapping distribution. Some fishes, m olluscs and other invertebrates also live on these seagrass beds,
but th e ir grazing is not significant com pared to that o f the green turtle. Am ong the m ajor forage item s o f adult green
turtles are the seagrasses Zoostera, Thallasia, Cym odocea, Syringodium , D iplantera, H alodule and Halophila, and the
algae Gelidium , G raciiiaria, G racilliaropsis, Hypnea, Caulerpa, Vidalia, Bryotham nion, Cryptonem ia, A gardiella, etc.
Together w ith this vegetarian food, sm all q uantities o f anim als living in these m eadow s are ingested indirectly but
th e y u s u a lly re p re s e n t le ss th a n 2% o f th e to ta l d ry w e ig h t o f th e s to m a ch co n te n ts.
Size : The size o f turtles is principally related to the carapace length, which is considered a reliable m easure o f overall
size. M easurem ents over the carapace curve (CCL) in adults are 3 to 4 cm larger than straight carapace length (SCL).
The available data som etim es do not indicate in w hich way the m easurem ents were done, and in such cases the
inform ation m ust be used as a reference o f relative value, bearing in mind that such records could be biassed by up to
4%. Because o f th e ir presence on the nesting beaches, size reports on fem ales are more com m on than those on males.
The mean size o f nesting fem ales show s wide va riatio n s from place to place. The largest green tu rtle s are those
recorded from the Comoro Islands (111.6 cm CCL) and the sm aller ones from Guyana (81.2 cm SCL); the heaviest turtles
are those from Australia (186 kg) and the lightest ones from the Solom ons (89.8 kg). The records o f size and weight are
respectively 139.5 cm (CCL), from Ascension Island, and 235 kg from Surinam. The minimum size and weight at maturity
are 78 cm (SCL ?), from the Solom ons and 68 kg, from Flawaii. Size data for m ales are very scarce; m easurem ents at
m aturity size range from a minimum o f 71 cm (CCL ?) to a m aximum o f 104 cm (CCL ?), both records from South Yemen,
w ith a mean size o f 90.4 cm W estern Sam oa m ales are a little bigger, 92.2 cm (SCL). Unconfirm ed records o f green
turtles captured in the W est Indies, probably during the early sixties, cite unsexed anim als o f 850 pounds (395 kg) with
carapaces over 5 feet (150 cm) long. In recent tim es, the sm aller adult m ales are those from Guyana, Solom ons and
Australia and the larger size records those from Com oros, Surinam, Ascension Island and Southeast Africa. In general,
m a le s are s m a lle r th a n fe m a le s.
In te re s t to F is h e rie s : The main com m ercial fishing gear used to catch green turtles are: entangling nets, drift-nets,
harpoons, grapnels, hooks and also “turning nesting fem ales onto th e ir backs” . Green tu rtle s are often taken as
bycatch in shrim p trawls, set-nets, gill-nets and beach seines, and som etim es ju veniles are captured w ith cast-nets.
O ther com m on m ethods are spear-gunning by scuba divers, and follow ing turtles closely in shallow w aters until they
get tired and are hauled up to the boat. Finally, an interesting m ethod o f turtle hunting is the use o f the “ living fish
hook” , the sucking fish or rem ora, that w as comm on in the Caribbean Sea, in Chinese w aters, Torres Straits and some
o th e r s o u th A s ia n lo c a litie s .
The m ajor “ Fishing A re a s” for green tu rtle s correspond to the sites o f im portant rookeries
already m entioned in the form er chapter, and capture may be increased during the breeding
principal product obtained from the green turtle, and the yield per anim al ranges from 20 to
weight. O ther products are calipee and calipash. Oil is obtained from the green or yellow ish fat.
o b ta in e d e ith e r from th e b u tch e re d tu rtle o r d ire c tly from th e n e stin g b e a che s.
and feeding grounds
season. M eat is the
25% o f its total live
Green turtle eggs are
The green turtle is considered the best species for com m ercial farm ing or ranching. International com m erce o f wild
green sea turtles is forbidden, but capture for use as a food for local consum ption persists in m any central Pacific
Islands, in Southeast Asia and Indonesia, Indian Ocean islands and m ainland coasts, east coasts o f Africa and Arabian
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30
peninsula, South A m erica (northeastern countries, C aribbean islands), M exico and Central A m erica (Atlantic-side
countries). All those places have had variable levels o f green sea turtle exploitation and some o f them were historically
im portant fresh-m eat exporters. The FAO Y earbook o f Fishery Statistics reports only data for Fishing Area 31 (W estern
Central A tlantic, 359 m etric to n s in 1987 o f which 291 correspond to Cuba), and Fishing Area 71 (W estern Central
Pacific, 46 m etric tons, Fiji only). The total reported catch o f Chelonia m ydas in recent years was: in 1982: 411 m etric
tons, in 1983: 432 m etric tons, in 1984: 282 m etric tons, in 1985: 719 m etric tons, and in 1986: 428 m etric tons.
The United States im ports o f turtle meat and calipee were registered up to the 1970’s, but since 1978-1979, they were
m ostly replaced by Caym an Turtle Farm products. European countries such as Switzerland, W est G erm any and the
United Kingdom , also were im porters up to the ban, proclaim ed in the late 1970’s, w hen they all signed the CITES
resolutions prohibiting the com m erce o f w ild sea turtle products. Flowever, some o f the countries that ratified the
CITES, decided that trade with Caym an Turtle Farm products could continue (W est Germ any, United Kingdom, France,
Italy, etc) but placed a reservation on green, ridley and haw ksbill turtles. Finally, all these reservations became
ineffective w hen the proposal to transfer sea turtles produced by farm ing or ranching from Appendix I to Appendix II
w as rejected at the last Conference o f the P arties, held in Buenos Aires, Argentina on 3 May 1985.
L o ca l N am es : ANDAM AN - NICOBAR Islands: Duch-kacchua, Yadi-da; BELIZE: W hite turtle; BRAZIL: Arauana, Aruana,
Suruana, Tartaruga, Uruana; CANADA: Green turtle; CAR IBBEAN: Kadaloe; C AR OLINE ISLANDS: (Palau) Melop,
(Ponape) Calap, (M arshall) W on, (Truk) W inim on, (Yap) W ei mwon; CO LO M BIA: Tortuga blanca or Verde; CUBA:
Tortuga Verde; ETFIIOPIA: (Eritrea) Nyamba; FIJI: Ika dame, Mako loa, Vonu damu, Vonu loa; FRANCE: Tortue franche,
Tortue m angeable, Tortue verte; FRENCFI G UIAN A - Tortue verte; G ERM ANY: S uppenschildkröte; GFIANA (Gold
Coast): A puhulu, G a-hala, N zim a-anjua; FIAWAII: Flonu; G UATEM ALA: Tortuga Verde; INDIA: T(am il) Peramai;
INDOCFIINA: Lemech, Vich; INDONESIA: Penyu daging, Penyu nijaul, Penyu sala; ITALY: T artaruga franca or Verde;
JAP AN : A o um i-gam e; M ALAY SIA: Penyu agar, Penyu pulau; M EXIC O : Tortuga blanca, Jacona (juvenile);
M O ZAM BIQ UE: Itaruca, Nrubi; (Swahili): Nyamba, Ewe-klo, Kassa; (Cabo Delgado) Assa; PHILIPPINES: Pawikan;
PORTUGAL: Tartaruga; SABA: Penyu, Timbau; SENEGAL: Tortue verte or franche; SEYCHELLES: Torti; SOUTH AFRICA:
Asa, Fano, Icaha, Ifudu; (Afrikaans) G roenseeskilpad ; SRI LANKA: Gal kasbava, Mali kasbava, Mas kasbava, Pai amai,
Perr amai; SURINAM : Krap’e; THAILAND: Tao-ta-nu; TO N GA (fem ales): T u’apolata, T u’a ’uli, Tongo tongo, Tufonu,
(males): Ika-ta’one; UK: Green turtle; URUGUAY: Tortuga Verde; USA: Green turtle; VENEZUELA: Tortuga de sopa or
T o rtu g a s fra n c a .
Literature : Boulenger (1889); Stejneger (1907); Babcock (1919); Bourret & lePolain (1941); Carr (1952, 1962, 1975); Cari
(1955); Carranza (1956); Rom er (1956); Loveridge & W illiam s (1957); W em urth & M erterns (1961); C aldwell (1962,
1962a. 1963, 1969); Carr & Hirt (1962); Achaval (1965); Kauffm an (1966); Ferreira (1968); Pritchard (1969, 1977, 1981);
Hirt & C arr (1970); M arquez (1970, 1977); Hirt (1971); M oiseev (1971) Bustard (1972); Carr & Carr (1972); M enezes
(1972); Hughes (1974); Schwartz (1974); Polunin (1975, 1981); Schultz (1975); Kowarski (1978); Kurata et al. (1978);
Lim pus (1978); Urlich & Parkes (1978); Smith & Smith (1979); Balazs (1980, 1981); Casas-Andreu & G om ez-Aguirre
(1980); Rhodin, Spring & Pritchard (1980); de Silva (1969, 1981); Chu-Chien (1981); Frazier (1981, 1981a. 1985); Geliday,
Koray & Balik (1981); Kar & Bhaskar (1981); Kuan-Tow & Moll (1981); Mendonca (1981, 1983); Spring (1981); Polunin &
Sum ertha (1981); Ross & Barwani (1981); Sella (1981); Sternberg (1981); Uchida & Nishiwaki (1981); Frazier & Salas
(1984); Pritchard & Trebbau (1984); Bonnet, leG all & Lebrun (1985); Fletem eyer (1985); Frazer & Erhart (1985); Ross
(1985); Depuy (1986); Lebeau (1986); M argaritoulis et al. (1986); Hendrickson (pers corn.).
Eretmochelys Fitzinger, 1843
CHEL Eret
G enus : Eretm ochelys Fitzinger, 1843, Syst. Rep., (p.30), 106 p.
T ype S p e cie s : Testudo imbricata Linnaeus, 1766, Syst. Nat., e d .12,Vol.I: 350 p,
S y n o n y m s : C aretta Ritgen. 1828; H e rp y s m o s te s G irtel, 1868; O n y c h o c h ely s Gray, 1873.
R e m a rks : The author considers this as a m onotypic genus. Several authors have described two species, one for the
Atlantic, E. im bricata, and one for the Indo-Pacific region, E. squam ata, and a third species, E. bissa, w as described
e arlier for the Red Sea. All o f these d escriptions are based on highly variable m orphological features as well as on
geographical distribution. O ther authors consider these taxa as having subspecific status. In fact, coloration and also,
the shape o f the carapace changes greatly with growth, from cardiform or oval in hatchlings and juveniles, to elliptic
in
adults. Hence, detailed statistical and genetic studies are required to ascertain the specific or subspecific validity o f
these m orphological characters.
31
Eretmochelys imbricata (Linnaeus, 1766)
Testudo im bricata Linnaeus, 1766,
CHEL Eret 1
Figs 29, 30
S ys.N at., Ed. 12, V o l.1:350 p. (Berm uda; restricted by Sm ith and Taylor, 1950).
Synonym s : Chelone im b ricata: Brongniart 1805; Strauch, 1862; C helonia im b ricata: Schweiger, 1812; Caretta
im b ricata: M errem, 1820; Chelonia p seu do -m idas Lesson, 1834; Chelonia p seu d o -caretta Lesson, 1834; Caretta bissa
Rüppel, 1835; Eretm ochelys im bricata: Fitzinger, 1843; Eretm ochelys squam ata Agassiz. 1857; Caretta squam osa
Girard, 1858; Herpysm ostes imbricata: Gistel, 1868; Onychochelys k ra u s s i G ray, 1873.
S u b s p e c ie s : See re m a rk s u n d e r g e n u s E re tm o c h e ly s .
FAO Names : En - H aw ksbill sea tu rtle ; Fr- Tortue caret; Sp - Tortuga de C arey.
Fig. 29
p re c e n tra l
s c u te
Diagnostic Features : Carapace in adults cardiform or
elliptical, w ith im bricated dorsal scutes, its w idth 70 to
79% o f its to ta l length (m ean 74.1% SCL). Head
m edium -sized, narrow, with a pointed beak, its length
21 to 33% o f the stra ig h t carapace length (mean
27.6% SCL); 2 pairs o f prefrontal and 3 or 4 postorbital
scales; tom ium not serrated on the cutting edge, but
hooked at the tip. The narrow and elongated snout
and the thick scutes o f the carapace are adaptations to
cope w ith w a ve s and to obtain food from between
c o ra ls and ro c k y s u b s tra te s .
The scutes are m ost strongly im bricated at m aturity,
but in o ld e r a n im a ls the o ve rla p p in g ch a ra cte r is
freq u e n tly lost. The scutelation o f the carapace is
sim ila r to that o f Chelonia, with 5 costal, 4 pairs o f
lateral (the first not touching the precentral scute), 11
pairs o f m arginal plus one pair o f postcentral or pigal
scutes. The plastron is covered by 5 pairs o f scutes, plus
one or tw o in te rg u la r and so m e tim e s one sm all
interanal. There are 4 poreless infram arginal scutes
covering each bridge. Each rear and fore flipper bears
2 claw s on its anterior border. A s in other species o f
sea turtles, m ales have stronger and more curved claws
and longer tails than fem ales. Hatchlings and juveniles
have a w id e r carapace than adults, the mean carapace
w idth usually exceeding 76% o f its length. They also
have three keels o f spines along the carapace which
disappear w ith growth. Young adults som etim es have
2 c la w s
4 la te ra l
s c u te s
c e n tra l
scutes*
m a rg in a l
s c u te s
p re fro n ta l
s c a le s
4 in fra ­
m a rg in a l
s c u te s
w ith o u t
p ore s
dorsal view of head
plastron
Fig. 30
32
a rem nant o f the dorsal central keel, w ithout spines. In juveniles and subadults, the scutes o f the carapace are indented
on the rear third o f the carapace m argin. Colour: this species is the m ost colourful am ong sea turtles. The pattern
show s a large range o f variation, from very bright colours to the heavy m elanistic form s in the Eastern Pacific. The
scales o f the head have cream y or yellow margins, more apparent at the sides or cheeks than on the roof. The colour o f
the thick, horny scutes o f the carapace is im portant in relation to the quality o f the “carey” which is determ ined by its
degree o f transparency, the intensity o f the am ber ground colour and the quantity and arrangem ent, in spots or
stripes, o f the com plem entary colours: brown, red, black and yellow. The colour spots and stripes are usually arranged
in a fan-like pattern. Underneath, the scutes are rather thin and am ber-coloured, in ju ve n ile s there are brown spots in
the rear part o f each scute. The dorsal sides o f head and flippers are darker and less variable; in the eastern Pacific
population, the coloration is som etim es nearly black. H atchlings are more hom ogeneous in colour, m ostly brown,
with paler blotches on the scutes o f the rear part o f the carapace, and also sm all pale spots on the “tip ” o f each scute
along the 2 keels o f the plastron
G eographical Distribution : Eretm ochelys is the m ost tropical o f all sea turtles. It is distributed throughout the central
A tlantic and Indo-Pacific regions (Fig. 31). The population density is low er than that o f L ep ido chelys olivacea', also
nesting is perform ed in a more w idespread pattern, with very few m ajor nesting places. The hawksbill is more comm on
w here ree f form ations are present; it is also observed in shallow w a te rs with seagrass or algal m eadows, including
coastal lagoons and bays. Nesting is confined between the 25°N and 35°S, mostly w ithin the tropical region, with very
few isolated records outside these latitudes. There are some records o f non-nesting tu rtle s outside the abovem entioned range, e.g. in the northern hem isphere: w estern A tlantic, up to Cape Cod, USA; eastern A tlantic, the
English Channel; western Pacific, China, up to the Yellow Sea, Shangtung region, and southern Japan -Archipelago o f
Ryukyu; eastern Pacific to Cedros Island, Baja California, Mexico. In the southern hem isphere: western Atlantic, up to
southern Brazil, but no data from Uruguay; eastern A tlantic, often observed in northern Nam ibia, but sporadically
down to the w est coast o f South Africa; W estern Indian Ocean, Red Sea as the northernm ost record (nesting ground)
and South Africa (Natal) as the southernm ost record; south-central Pacific, up to New Zealand; eastern Pacific, up to
southern Peru, no records a va ilable from C hile; isla n d s o f the Central Pacific, m ainly rep o rts o f nesting grounds.
T his is one o f the sea tu rtle s whose ju venile stages have m ost often been sighted, especially from intentional or
incidental catches in com m ercial fishing gears used in coastal shallow waters, and from captures by scuba-divers. There
are reports o f m ultiple recapture o f the same young individual
at the same place.This would suggest that at least part
o f the pop ulatio n has reside n tia l o r n o n -m ig ra to ry behaviour.
80"
Í0"
20"
20 "
60"
20»
Fig- 31
33
H abitat and B iology : Hawksbill tu rtle s live in clear, littoral w a te rs o f m ainland and island shelves; they perform
m igratory m ovem ents that cause variations o f population density in certain areas and seasons. Frequently, individuals
o f several ye a r classes are found to g eth e r on the same feeding grounds. A nother feature o f this species is that up to
now, it has not been observed travelling in “flo tilla s” . Studies on m igrations have revealed short as w ell as long­
distance m ovem ents, at least for parts o f the population; during the breeding period, the m ost com m on are short
displacem ents between the nesting beach and the nearest offshore (feeding) bank, as in Tortuguero, Costa Rica, or
slightly longer travels, i.e. from the same nesting beach to Miskito Cays in Nicaragua, from the nesting place on Isla
M ujeres, M exico, to Bani in the Dom inican R epublic (presum ably the feeding ground), from Y ucatan, M exico to
southern Cuba, from Nicaragua to Jam aica, and from northern A ustralia to Papua/N ew Guinea. M igrations am ong
the islands in Philippines, Indonesia, Java, or along M alaysia and Sarawak are probably perform ed by solitary turtles or
by sm all groups, but no data are available. It is suspected that m igrations also occur am ong the groups o f islands o f
Oceania.
The haw ksbill turtle repeatedly has been considered a solitary nester; although it does not form real “arribazones” ,
there are few nesting beaches w here fem ales arrive in larger groups. A s in other sea turtles, the hawksbill show s
nesting site fixity, which is more frequently observed am ong o lder individuals. However, subsequent nesting on
beaches oth er than the original one also seem s to be possible. Nesting occurs during the warm and rainy season,
principally in sum m er, but it generally starts at the end o f spring. T his turtle has a nesting cycle o f 2 or 3 years, with a
mean around 2.6 years.
M ost haw ksbills nest at night, but there are reports o f day-tim e nesting, as well as basking behaviour, principally on
uninhabited or low -inhabited beaches, such as those on W estern Indian Ocean islands.
In the A tlantic, there are several m ajor nesting grounds, often located in the proxim ity o f coral reefs, e.g. on the
Yucatan Peninsula: Isla Aguada and Rio Lagartos, with at least 500 nests per year in each site. Other nesting areas are
in southern Cuba, with several hundred nests; some islands o f the Caribbean, such as: Jam aica, Dom inican Republic,
Turks and C aicos, and G renada, each one w ith about 100 fe m a le s nesting per year. The nesting gro u n d s in
northeastern Brazil are visited by about the same num ber o f fem ales each year. Some islands o f the Indian Ocean, e.g.,
Seychelles, w ith over 600 nests or 300 turtles each year, British Indian Ocean Territory, with over 200 turtles, Comoro
islands, with less than 100 turtles; Aldabra, with about 25 turtles, Am irantes, with about 150 turtles, Providence, with
about 40 turtles, La Reunion, with about 50 turtles, Sri Lanka, with a few dozen turtles, southeast India (Tamil Nadu)
with a few dozen turtles, and also the M aldives/Laccadives. In certain places, the presence o f hawksbills is reported as
“common” ,e.g., Iran, Somalia, Kenya, Tanzania, Madagascar and northern Mozambique. In the Eastern Indian Ocean,
nesting occurs on the A ndam an and N icobar Islands and eastern M alaysia. Nesting apparently is more dispersed
elsew here, e.g. in the Indonesian Archipelago, with sm all concentrations quoted for southern Sum atra, Java,Bali,
Sum bawa, and Celebes; in the P hilippines (southern part o f the Sulu Sea, on the “ Philippine Turtle Islands” , etc.);
along Irian Jaya, Papua New Guinea, Solomon islands, Fiji Islands, northern Australia and on the Leeward islands in the
north o f the Great Barrier Reef. Nesting has also been reported from the Pacific islands o f M icronesia and Polynesia,
but rarely from Hawaii. In the eastern Pacific, from Mexico to Panama, nesting is spread thinly, or rarely with sm all
concentrations in the latter country and on the M exican Pacific Islands.
The nesting season occurs m ostly toward the end o f spring and throughout sum m er, usually before the peak o f the
green turtle season, som etim es another peak for the hawksbill appears after that o f green turtle, e.g. in Tortuguero,
Costa Rica. Some exam ples o f tim ing o f the nesting season are the following: W estern Atlantic: coast o f Mexico, from
April to August, with a peak in M ay-June; Belize and Cuba same season as in M exico, with a peak in June-August;
Puerto Rico, from March to November; Jam aica, from May to Septem ber; G uatem ala, from May to November, with a
peak in June-August; Honduras, from June to Septem ber; Nicaragua, from May to October; in Costa Rica, from May to
November, w ith a peak in M ay-June; US Virgin Islands, from June to December, w ith a peak in August-S eptem ber;
Turks and C aicos from April to August; Dom inica Islands, from April to October; Guyana, Surinam and French Guiana,
from May to August, with a peak in June-July; Colom bia, from April to A ugust (very few tu rtle s today); Brazil, from
Decem ber to March. Eastern Atlantic - Cabo Verde, from May to August. W estern Indo-Pacific: Oman, from February
to April; South Africa, from April to July; Com oro Islands, from O ctober to June, with a peak in January-M arch;
S eychelles, from Septem ber to January; Laccadives Islands, in O ctober; India (Tam il Nadu), from Septem ber to
February; A ndam an Islands, from O ctober to December; Burma, from June to Septem ber; Philippines, from May to
August; China, from March to April; Japan, from June to
O ctober; Palau, from July to August; New Hebrides, from
Septem ber to January; New Caledonia, from N ovem ber to March; Solom on Islands, from March to August; Irian Jaya,
from May to Septem ber; Papua New Guinea, from March to Septem ber; A u stra lia -T o rre s Strait, from Decem ber to
February. C entral Pacific Islands: Tokelau, from Septem ber-O ctober; M icronesia, from May to Septem ber; W estern
Samoa, from Septem ber to February, with the peak in January to February; Fiji, from N ovem ber to February. Eastern
Pacific: M exico, from May to October; El Salvador, from July to Decem ber; Honduras, from A ugust to November;
Panama, from May to December; Ecuador M ainland, from Decem ber to May.
Some reports quote renesting intervals o f around two w eeks, others o f nearly three w eeks. It is possible that both
intervals are correct and that such periodicity depends o f unknown internal and external factors. Also, in succeeding
nesting periods, fem ales may shift from one type o f interval to another or show irregularities during the same nesting
34
season. The interval most frequently quoted is the one extending for 2 weeks. For this species five or more subsequent
nestings, with anaverage num ber o f 2.3 clutches per season have been recorded.
Judging from the total num ber o f eggs per clutch, the hawksbill has the highest mean individual fecundity am ong sea.
turtles. W hen taking into account the num ber o f tim es each fem ale nests per season, together with the nesting cycle o f
2-3 years, the fecundity o f the hawksbill is com parable to that o f the Kem p’s ridley, which in average nests only 1.5
tim es per season but has a shorter nesting cycle o f nearly every year. Pressure from predation probably has influenced
the evolution o f th is feature; it is possible that m ortality during incubation is higher in the haw ksbill nests due to
hazardous co n ditions o f the nesting places, usually am ong bushes and farther from the s u rf zone, and hence, the
increase in m ortality m ust be com pensated by higher fecundity. Also the leatherback lays few er eggs, but the nesting
place is very near to the su rf zone. A com parative study is needed to clarify such param eters, but there is no doubt that
higher fecundity is a biological com pensation for high m ortality. In haw ksbills, the num ber o f eggs per clutch is highly
variable, and the data are also som etim es biassed by the presence o f sm all and yolkless eggs, but never in substantial
quantities as in the leatherback turtle.
Som e exam ples o f variation in clutch size are the follow ing: M e x ic o , Isla A guada, C am peche, fro m 71 to 202 eggs, with a m ean o f 135 (n = 163
clutches); in R io L a g a rto s , Yucatan, from 93 to 223 eggs, with a mean o f 150 (n = 114 clutches); USA, Virgin Islands, from 51 to 211 eggs, with a mean
o f 141 6 (n = 39 clutches); Puerto RICO, with a m ean o f 157 eggs; C osta R ica, Tortuguero, from 86 to 206 eggs, w ith a m ean o f 158 (n = no data);
Guyana, from 139 to 176 eggs, w ith a mean o f 157 (n = 7 clutches); S u rin a m , from 112 to 179 eggs, w ith a mean o f 146 (n = 13 clutches); O m an, from
81 to 113 eggs, with a mean o f 97 (n = 9 clutches), fo r the sam e area, also a mean o f 108 is quoted; S o u th Y em en, from 96 to 127 eggs, with a mean of
107.8 (n = 5 clutches); S e yc h e lle s Isla n d s, from 125 to 197 eggs, with a mean o f 161 (n = 64 clutches); A n d a m a n , N icobar Islands, with a mean o f 130
eggs; A u s tra lia , Torres Strait, from 89 to 192 eggs, with a m ean o f 131.8 (n =47 clutches); F iji, fro m 68-168 eggs a m ean o f 116.9 (n = 8 clutches);
W e ste rn Sam oa, from 59 to 213 eggs, with a mean o f 145.7 (n = 23 clutches); T ru k Is la nd s, from 110 to 152 eggs (n = no data); S o lo m o n Is la nd s, from
75 to 250 eggs, w ith a m ean o f 137 5 (n = 164 clutches).
Egg diam eters are often reported in the literature (range: 30 to 45 mm), but data on egg m ass or w eight o f the clutch
are relatively scarce (range: 20 to 31.6 g).
Som e exam ples are the follow ing: M e x ic o , Y ucatan Peninsula: egg size from 34 to 42 mm, w ith a m ean o f 36.2 (n = 3 clutches, 216 eggs); egg m ass
from 28.6 to 32.5 g, with a mean o f 30.8 (n = 122); C osta R ica, Tortuguero: egg dia m e te r from 35.1 to 39.6 mm, with a m ean o f 37.7 (n = 13 clutches,
363 eggs); USA, Virgin islands: egg diam eter from 39 to 40 mm (n = no data); G u ya n a: egg diam eter from 36 to 40 mm (n = no data); F re n c h G u ian a :
egg dia m e te r from 35 to 42 mm; egg m ass from 20 to 30 g (n = no data); R ed Sea, Sudan: egg d iam eter from 37 to 42 mm, with a m ean o f 40 (n = 2
clutches, 20 eggs); S o u th Y e m en : egg diam eter from 38 to 45 mm, with a m ean o f 40 (n = 1 clutch); Sri Lan ka : egg diam eter from 35 to 38 mm, with a
mean o f 36 (n = 1 clutch, 19 eggs), egg m ass from 26.2 to 27.6 g, with a mean o f 26.7 (n = 1 clutch, 5 eggs); In d ia , Tam il Nadu: egg diam eter from 30 to
35 mm (n = 103 eggs); A u s tra lia , C am pbell Islands: egg diam eter from 32.3 to 40.7 mm, w ith a mean o f 36.4 (n = 47 clutches,470 eggs), G reat B arrier
Reef. NW: egg diam eter from 33 to 38.9 mm, with a mean o f 36.4 (n = 7 clutches, 70 eggs), egg m ass from 22.5 to 30.5 g, with a mean o f 26.4 (n = 6,
60); P h ilip p in e s : egg d iam eter from 31 to 35 m m (n = 1 clutch), egg m ass from 20 to 22 g (n = 1); In d o n e s ia : egg diam eter from 33 to 39 mm, w ith a
mean o f 36, egg m ass from 20 to 31.6 g. w ith a m ean o f 24.2 g (n = 20 eggs); W e s te rn S a m oa : egg diam eter from 34 to 36 mm, w ith a m ean o f 34.7
(n = 23 clutches, 194 eggs), egg m ass from 23 to 25.9 g, with a m ean o f 24.4 (n = 3 clutches); M ic ro n e s ia : egg diam eter from 33 to 36 mm, m ean egg
mass 23 g (n = no data).
The duration o f the incubation in days varies am ong separated nesting beaches and also along the season. It may last
from 47 to 75 days, depending on the place and tim e.
In M e x ic o (Cam peche), 1988, it extends from 44 to 54 days, with a mean o f 49 days (n = 15) fo r undisturbed nests, and from 49 to 65 days, with a mean
o f 56.1 d ays (n = 145) fo r box-hatchm g; in Costa Rica, fo r transplanted nests, from 52 to 74 days, with a mean o f 58 6 (n = 13); in B a rb a d o s , from 60 to
65 d ays (n = no data), in G re n a da , fo r transplanted nests, from 65 to 82 days, w ith a m ean o f 75 (n = 34); in th e U SA, V irgin Islands, a mean o f 62.4
d ays (n = 7) in 1980 and 66.5 d ays (n = 21) in 1981, in W e s te rn S am oa, fo r transplanted nests, from 59 to 70 days, w ith a m ean o f 62 days (n = 23); in
F iji, fo r transplanted nests, from 61 to 66 days, with a mean o f 63 days (n = 4); in the S o lo m o n Is la n d s , fo r undisturbed nests, from 43 to 90 days, with a
mean o f 64.4 days (n = 174), in S ri Lanka, fo r transplanted nests, a m ean o f 62.5 days (n = 2); in S e y c h e lle s fo r undisturbed nests, from 56 to 79 days,
w ith a mean o f 62 days (n = 31); in north-eastern A u s tra lia , C am pbell islands, fo r transplanted nests, from 52 to 57 days, w ith a m ean o f 55 days
(n = 5).
Data on size and body m ass o f hatchlings range from 38 to 46 mm, and from 8 to 17.9 g; respectively.
Such data are available fo r the follow ing places: M e xico , Yucatan P eninsula, carapace length from 38.1 to 43 mm, with a mean o f 41 .1 (n = 36), body
m ass from 12.1 to 17.9 g, with a mean o f 12.6 (n = 23); C osta R ica , La U vita Islands, mean carapace length 40 mm, body m ass 15.6 g (n = 137) and
Tortuguero, carapace length from 39.1 to 45.9 mm, w ith a mean o f 42.4 (n=41); C o lo m b ia , carapace length from 39.2 to 44.1 mm, w ith a m ean of
42.3, body m ass 17.1 to 19.2 g, with a mean of 18.1 (n = 25); S u rin a m , carapace length 41.3 to 43.7 mm (n = 10); F re n ch G uiana, carapace length 38 to
46 mm, body m ass, 15 g (n = no data); G re n a da , carapace length from 42 to 45 mm, with a m ean o f 44, body m ass from 16.3 to 18.5 g, w ith a mean o f
17.5 (n = 319); USA, Virgin Islands, mean carapace length 43.7 mm (n = 47); S o u th Y em en, carapace length 42 mm (n = 1); Sri Lanka, carapace length
from 39 to 40 mm, body m ass 14.6 g (n=3 and 2); In d ia , Tam il N adu, mean carapace length 35 mm , mean body m ass 12 g (n=63); W e s te rn S am oa,
carapace length from 38 to 41 mm, with a mean o f 39.6 (n = 235). body m ass 12.1 to 13.2 g (n = 3 clutches); A u s tra lia , C am pbell Islands, carapace
length from 38.2 to 43.8 mm. with a mean o f 41.1 mm, body m ass from 12.7 to 16.8 g, with a mean o f 14.3 (n = 7 clutches, 70 hatchlings); P h ilip p in e s ,
body m ass from 8 to 11 g, with a mean o f 9.4 (n = 14); Sabah, body m ass from 10.7 to 12.4 g, with a mean o f 11.4 ; F iji, body m ass from 12 g (n = 128);
S o lo m o n Isla nd s, body mass 13.2 g (n = 120); M icro n e sia , body mass 13.0 g (n = no data).
H atchlings em erge m ainly during the first hours o f the night, w hen sand tem perature is below 28°C, above this
tem perature th e ir a ctivity is inhibited. A s in the o ther species, the sm all tu rtle s run rapidly to the s u rf zone; after
reaching the sea they d isappear for an unknown period and are again observed when approaching coastal shallow
w aters at sizes usually over 20 cm o f carapace length (SCL). Age at sexual m aturity is uncertain; old reports quote ages
from 3 to 4.5 years, but these fig u re s were obtained from tu rtle s reared in captivity, and it is assum ed that for wild
stocks they m ust be m uch higher. Furtherm ore, the figures for age at first m aturity should be diffe re n t if they are
correlated to the mean carapace lengths observed on nesting beaches and if all size data are obtained from m easure-
35
m erits o f straight carapace lengths. Under such circum stances, the first m aturity o f fem ales should be reached at sizes
between 68 and 80 cm (SCL) and at body w eights from 40 to 56 kg depending on the locality. It is suggested that m ales
reach m aturity at sim ilar sizes but no data are available to confirm this assumption.
There are few reports on courtship and m ating; both have been observed in shallow waters. During m ating, the male
holds the fem ale by using its claw s and tail, and th is operation may last several hours. It has been observed that
fem ales are more receptive after nesting and that they com m only receive attention from several m ales w ithout having
preference for any special partner. Hence, polygamy is the normal pattern.
The optim al incubation tem peratures recorded on Cam pbell Island, Australia range from 27.3°-31.8°C (at 50 cm depth,
at the bottom o f the nest) and from 28.9°-32.4°C (at 30 cm depth, at the side o f the egg mass). Figures from Eastern
Samoa showed an increase o f 3.6° (range 2.7-5°C) above the sand tem perature at equal depth. On Isla Aguada, Mexico,
am bient tem perature and sand egg m ass tem perature were closely correlated, the changes in tem perature o f the egg
m ass norm ally dephasing by several hours; however, abrupt tem perature decreases were observed during rainfall. The
incubation tem perature in translocated nests ranged from 27.2° to 33.5°C (n = 54 clutches) thro u g h o u t the 1985
season, and from 28.5° to 30.5°C (n = 32 clutches) for the second third o f the incubation period in 1986.
Studies on sex determ ination related to incubation tem perature are currently in progress on the Isla Aguada nesting
beach (M exico); no data are available for other nesting beaches. The critical, pivotal or threshold tem perature and
tim e at which the sex o f the hatchling is determ ined apparently is one or two degrees low er than for other sea turtles
(29° or 30°C), because the hawksbill is prone to nest in shadow y places; to balance the sex-ratio, m echanism s other
than tem perature must be brought into play.
A s the other sea turtles, this species is subjected to predation throughout its life-cycle. The eggs and em bryos are
consum ed by several species o f ghost crabs (O cypode sp.), nearly throughout the nesting range, on the m ainland as
well as on insular beaches; predation also affects the hatchlings in and outside the nest. M am m als like genets and
m ongooses are reported as predators o f eggs in the Indian Pacific Islands, South Africa and also in the US Virgin Islands,
Barbados and G uadaloupe, w here the introduced m ongoose (H erpestes sp.) is one o f the main causes o f predation;
skunks and raccoons are comm on on beaches o f Mexico and are quoted as predators o f nests and hatchlings. Iguanas
are reported on beaches o f Cuba, and although direct predation has not been observed, it is possible that these reptiles
eat the rest o f the nest following the predation by other anim als such as raccoons. In some areas, rats are reported as
potential predators (the Polynesian rat - R attu s exulans). Jackals, pigs and feral dogs also dig out nests, the latter two
in connection w ith the presence o f human dw ellings in the neighbourhood o f the nesting beaches. M onitor lizards
(Varanus sp.) are im portant nest predators on m ainland Africa, India, Cam bodia, northern Australia, the Philippines,
and Andam an/N icobar Islands. Birds such as frigates, herons, vultures, kites, crows, etc., eat hatchlings when they
em erge in day-tim e. The barn owl (Tyto alba) is quoted as a crep u scu la r predator o f h a tchlin gs in the Com oro
Archipelago. In the w ater, hatchlings are captured by sea birds (frigates, gulls, etc.), and carnivore fishes, e.g., tunas,
dolphin-fish and jacks, or sharks as w as docum ented for Saraw ak and Samoa. Because o f its occurrence around coral
reefs, w here big carnivore fishes remain in am bush, this turtle is continuously exposed to heavy predation, and not only
hatchlings, but also juve n ile s and adults are attacked by those big carnivores, principally sharks (e.g. the tig e r shark G aleocerdo cuvier). A part from predation, no o ther kinds o f natural m ortality have been docum ented, and there are
no reports on derm ic papillom ae. Com m only these tu rtle s are covered by e p ib io tic organism s, e.g., green algae
som etim es form a rug over the carapace in old individuals; also leeches, barnacles, sm all pelagic crabs, other crustacea
and nudibranchs are often observed.
T his is a carnivorous turtle, com m only poking in crevices between rocks and corals, so the diet often is highly variable.
Up to around 10 cm o f SCL the hawksbill apparently is a nectonic anim al, and w hen it approaches coastal areas, it
changes over to benthic feeding, and becom es a regular inhabitant o f hard substrata w here its diet consists principally
o f corals, tunicates, algae, and sponges. Some data on stom ach contents from several studies are the following: a)
Juveniles: for Salvage Island (Canary Archipelago), coelenterates (Anem onia, hydroids, siphonophora, especially
Velella, hydrom edusae), algae (Stypodium , Sargassum , Dyctiota, cyanophytes), gastropods (L ittorina, Am yclina,
Janthina), cephalopods ( Taonius, Histioteuthis, Oegopsida), sponges (2 species), spider crabs (Inachus), sea urchins,
stones, and plastic m aterials; for Taiw an Island, algae, shells, and bark, b) Subadults: for M agdalena Bay, M exico,
crustaceans and red lobsterets (Pleuroncodes); for Australia (subadults and adults), ascidians, encrusting anim als and
algae; for French Guiana, sponges, tunicates, coelenterates, m olluscs, algae, and angiosperm es; for Ascension Islands,
Costa Rica (Tortuguero), Hawaii (3 samples), Seychelles, Aldabra, Oman, Cousin Islands, mainly sponges (Dem ospongiagroup); for H onduras: m angrove leaves and fruits, bark and w ood; for New Zealand, barnacles, cephalopods,
siphonophores (Velella), and tunicates (Salpa)', for the Philippines, seagrass and sponges, (Echeum a, Codium)', for Sri
Lanka, algae, corals, gastropods, and ascidians; for the Seychelles, sargassum weeds, sponges and algae; for South
Yem en, green algae. Com prehensive studies o f the diet were made by Carr and Stancyk (1975). and th e ir conclusion for
the Tortuguero h a w ksb ill’s population w as that it consists m ainly o f sponges o f the group D em ospongia, and that
com petition with other species w ithin this niche is rare; in fact, E retm ochelys is the only known spongivore marine
reptile (M eylan, 1988); and s tric tly sp o n givore ve rte b ra te s include o n ly a sm all n u m b e r o f te le o ste a n fishes.
36
Size : The mean straight carapace length (SCL) in adult fem ales o f this species ranges from 53 to 114 cm, but has been
re p o rte d to be h ig h ly v a ria b le .
The nesting population with the sm allest carapace size is found in Sudan, with a range from 53.3 to 73.7 cm and a m ean o f 66.0 cm (n = 42); larger
sizes have been reported fo r Yucatan, Mexico, with a range from 76 to 114 cm, and a mean o f 94.4 cm (n = 57). Som e other m easurem ents o f nesting
fem a le s differing from those referred to above are quoted in the literature. It is assum ed that there m ust be an ecological explanation fo r the size
differences at average m aturity, and also, fo r age differences at first m aturity, but m ore com prehensive studies are needed to clarify th is variability.
O ther size data on nesting fe m a le s are reported fo r the follow ing localities: M exico, C am peche, fro m 86 to 99 cm (CCL), with a m ean o f 92.9 cm
(n = 9), Yucatan, from 76 to 114 cm (CCL), with a mean o f 94.4 cm (n = 57), Ouintana Roo, from 74 to 101 cm (CCL), with a mean o f 86.5 cm (n = 30);
N icaragua, from 62.5 to 87 cm, w ith a m ean o f 76.5 cm (n = 32); Costa Rica, Tortuguero, from 72.4 to 94.0 cm w ith a mean o f 82.0 cm (n = 180);
Colombia, from 80 to 95 cm (CCL), with mean o f 90.7 cm (n =4); Guyana, from 80.0 to 88.9 cm, with a mean of 83.8 cm (n = 23); Puerto Rico, from 67.5
to 85.6 cm. with a mean of 77.6 cm (n = 4); South Yemen, from 63.5 to 72.4 cm, with a mean of 69.4 cm (n = 15); Oman, from 60 to 83 cm, with a mean
o f 73.3 cm (n = 48); Sudan, from 53.3 to 73.7 cm, with a mean of 66.0 cm (n = 42); W estern Samoa, from 60 to 73.5 cm, with a mean of 68.6 cm (n = 7);
Solom on Islands, from 68 to 93 cm, with a mean o f 80.5 cm (n = 85); Seychelles, from 83 to 91.5 cm (CCL), with a mean of 89.5 cm (n = 9); Australia,
To rre s S tra it, fro m 70.7 to 8 3.3 cm , w ith a m ean o f 76 3 cm (n = 22).
Data for carapace length o f males, range from 16 to 85 cm (juveniles, adults).
Such data are available fo r the follow ing localities: Nicaragua: from , 71.4 to 85.1 cm , with a mean o f 77.8 cm (n = 17). Also the Inform ation on size of
juveniles and im m atures is not very common: Mexico, Yucatan, from 16 to 62 cm (CCL),with a mean o f 34.8 cm (n = 330); Nicaragua, from 21.5 to 49.5
cm, with a mean o f 35.5 cm (n = 10); Com oro Islands, from 34 to 67 cm (SCL), with a mean o f 44 cm (n = 13); South Africa, from 18.4 to 58.5 cm (CCL),
with a mean o f 38.3 cm (n = 11); Japan, Okinawa, from 36.7 to 42.3 cm (SCL), with a mean o f 40.2 cm (n = 4); New Zealand, 39.7 cm and 6.5 kg (n = 1).
The body m ass o f tu rtle s on nesting beaches, feeding grounds or in m arkets is difficult to obtain.
Some of the available figures are the follow ing: Mexico, fem ales, from 39 to 62 kg, with a mean o f 54 kg (n= 5); Nicaragua, fem ales from 27.2 to 86.2
kg, w ith a mean o f 54.2 kg (n = 32), males from 50 to 65.7 kg, with a mean of 53.4 kg (n = 17), and im m atures from 1.36 to 13.6 kg, w ith a m ean of
6.25 kg (n = 10); Costa R ica, fem ales from 46 to 69 kg, w ith a mean o f 59 kg (n = 16); Puerto Rico, fem ales, from 60.5 and 76.3 kg (n = 2); Solomon
Islands, fem ales from 36 to 77.3 kg, w ith a mean o f 61.9 kg (n = 83); Yem en, fem ales from 35.3 to 50.0, w ith a mean o f 43.2 kg (n = 15); A ustralia,
fem ales from 38.5 to 68 kg, w ith a mean o f 51.5 kg (n = 38)
Interest to Fisheries : The hawksbill is a unique species, because in addition to all the products com m only obtained from
o ther sea turtles, it also yields the brightly-coloured, thick scutes covering the carapace, which are o f high value in the
international m arket. These flexible scutes, the so-called “Carey” or “torto ise -sh ell” are m ainly used in jew ellery. The
term “tortoise-shell” applies to the raw m aterial o f scutes, while “Carey” refers
to the w orked to rto ise -sh ell.
In the
old
world, this species has been exploited since the pharaonic period, and in China its exploitation dates back to stillmore
ancient tim es. From China it w a s introduced to Japan in the Nara Period (A.D. 745-784) in the form o f ornam ental
articles reserved exclusively for the aristocracy to sym bolize a high status o f nobility. Handicrafts made o f tortoise-shell
appear to have florished in many ancient cultures, in places like Ceylon, India, Rome, Oceania, etc.
In m any other cultures, the hawksbill and
o ther sea turtles, were exploited only for th e ir m eat and eggs. Up to the
sixties and seventies o f this century, the
com m erce
o f the tortoise-shell, raw and w orked, showed an extraordinary
increase, and many countries were engaged in the export-m arket to Hong Kong, Japan, Singapore, China and Korea, in
Asia, and to Italy, W est G erm any, France, the UK and Spain, in Europe.
Also the m arket for stuffed tu rtle s had
increased to incredible num bers up to recent years. In the presence o f such a global m arket it is actually surprising that
there are still haw ksbill tu rtle s left in the
tropical seas o f the world. Noprecise fig u re s are available for the huge
quantities o f raw and worked tortoise-shell and o f stuffed hawksbill turtles com m ercialized in the past two decades
(60’s and 70’s), but it is known that about 90% o f the products were im ported by Japan; part o f this is docum ented by
the Japanese Custom Statistics. The internal m arket in each country is difficult to evaluate because o f the dispersed
nature o f the handicraft industry.
T ortoise-shell and Carey are processed in sm all-scale indigenous industries o f Southeast Asia, the C aribbean, the
Seychelles, M icronesia (O ceania), and elsewhere; they produce low -quality souvenir trinkets, carved directly on the
backshell scutes. But the bekko Japanese craftsm en elaborately shape the scutes, hooves and plastron pieces and blend
the natural colours, using a technique com bining w ater, steam, heat and pressure. Only the French and Italian artisans
are known to em ploy sim ilar tech niqu e s to produce high-quality products. H istorically, the bekko je w e lle ry w as
dedicated to the hair ornam ent o f Japanese brides. Today, a huge variety o f designs o f jew ellery, eyeglass fram es, inlay
boxes, combs, pins, etc., are produced and used nearly exclusively for domestic consumption in Japan.
Because o f the peculiarity o f the hawksbill m arket, any size o f tu rtle s are captured, the sm aller ones for stuffing and
the big ones for the scutes, and in many places also for the m eat and the eggs. Today, the com m erce with eggs is
prohibited in m any o f the countries. W ith the CITES restrictions, the exports o f carey scutes, particularly since 1979,
have decreased substantially, and only few co u n trie s retain a reservation
effective for the haw ksbill, and hence
continue im porting its products. In the m ajority o f the form er exporter countries, the com m erce today is reduced to the
internal dem and m ainly for m eat and tortoise-shell. Com plete and up-to-date statistics for each country are not
available, but the im portation o f hawksbill scutes by Japan in 1987 and 1988 w as published in the new sletter o f Traffic
(USA) in January 1989, and according to that the m ost im portant exporter w as Cuba with 13 905 kg for both years,
followed by Haiti, with 7 641 kg, the M aldives, with 7 436 kg, the Solom on Islands, with 7 369 kg, Jam aica, with 6 827
kg, the Com oro Islands, with 4 566 kg, Fiji, with 2 837 kg, Singapore, with 1 009 kg. All the other countries trading in
37
hawksbill scutes were exporting less than one m etric ton per year, e.g. St. Vincent, Ethiopia, Dom inican Republic,
Grenada, Antigua - Barbuda and Brunei. In 1987, other very im portant form er exporters becam e parties o f CITES:
Indonesia, Philippines, Singapore the Dom inican Republic. The total im ports by Japan, o f Carey scutes, for these two
years were: 29 808 kg in 1987 and 25 043 kg in 1988 (up to Novem ber only).
A very im portant m arket for stuffed hawksbills w as
by Japan was increasing from 9 329 kg in 1970 to a
decreased, down to 8 855 in 1986, and a total ban
1986 were: Indonesia, Singapore (until 1984). China
developed during the seventies. The im portation o f stuffed turtles
m aximum o f 85 843 kg in 1983; after that year, the im ports steadily
is expected during 1989. The principal exporters between 1970 and
(Taiwan island), Philippines (until 1980) and Hong Kong.
The size o f stuffed tu rtle s is highly variable, usually ju veniles are used for this purpose, but often also big adults appear
on the m arket. Since the ratio for converting dry w eights (stuffed turtles) to live w eights is not yet available, the total
num ber o f turtles used for this m arket is still unknown. For statistical purposes, the stuffed hawksbill is called in Japan
“worked bekko” to distinguish it from the “w orked to rto ise -sh ell” , which includes all the stuffed species except the
hawksbill.
In the FAO Yearbook o f Fishery Statistics, catches o f Eretmochelys im bricata are reported only for the W estern Central
A tla n tic (Fishing Area 31), totalling 318 m etric tons in 1987 m ostly by Cuba (277 m etric tons) and the Dom inican
Republic, 41 m etric tons. These data refer to entire anim als. If we com pare the statistics o f hawksbill im ports reported
by Japan, with the data reported by FAO, the latter appear to be very incom plete. It is possible that hawksbill catches
are included under the item “ M arine tu rtle s n.e.i.” (unidentified species) but it is not possible, at present, to calculate
the proportion o f h a w ksb ills in the catches.
As with other species o f sea turtles, the hawksbill is usually captured by turning over the fem ales when they crawl onto
the beach to nest. This method is widely used by riparian people nearly everywhere the
hawksbill nests.
The harpoon is
another com m on m ethod to capture turtles, but now adays, entangling nets o f different m esh-sizes, made o f natural
fibres or m onofilam ent-nylon, are becom ing a more effective and less tim e-consum ing fishing gear. Not withstanding
th e ir great diversity, these nets have some com m on features, especially the large m esh-size and the light bottom -lines
that allow the captured tu rtle s to reach the w a te r surface and breathe. Length and depth are variable and usually
several nets are joined to enlarge the area covered; also floating decoys are used in the head line to attract males.
Seines with finer mesh are set to surround the turtles in forageing areas. Scuba-diving is o f special im portance in the
capture o f this species, but the use o f spear-guns is more popular and productive around reefs; harpoons, hooks and
ropes are used also by divers. Rem oras were used by Caribbean people even before the discovery o f Am erica, and this
fish, known as “ pega-pega” on the Spanish-speaking islands o f the Caribbean, was or still is, used in other places such
as Sri Lanka, Kenya, Yem en, Somalia, M adagascar and northern Australia.
Eggs are collected directly on the nesting beaches, while the m eat com es from overturned fem ales or turtles captured
at sea. The skin is o f low er quality than that o f the olive ridley.
A m ong co ra l-re e f organism s consum ed by man, a sm all num ber is considered to be toxic, and one o f these is the
hawksbill turtle. In some places, these turtles are avoided as food because o f the high risk o f intoxication. Apparently,
a high percentage o f fa ta litie s resulting from the consum ption o f hawksbill m eat has occurred in the Indo-Pacific
region, Oceania; two fatal cases were quoted for the Caribbean in 1967, but the species o f turtle that caused them was
not identified. In some o f the reported cases, the other species implicated is C helonia m yd as.
Poisoning by haw ksbills has been quoted by several a uthors and in som e cases, a great num ber o f deaths were
reported, m ainly in India, Sri Lanka, China (Taiwan Island), Philippines, Indonesia, P apua/N ew Guinea, northern
A ustralia (Torres Strait), Central Pacific (Arorue, G ilbert Islands), and Caribbean (W indward Islands). Intoxications were
also produced by the green turtle Chelonia mydas, and some other cases were caused by unidentified species. In a short
paper produced in Australia by Lim pus (1987), general inform ation is offered on the toxine, the m edical aspects o f the
intoxication, treatm ent and prevention, and it is recom m ended not to eat hawksbill turtle m eat in areas w here toxicity
has been reported.
Local nam es : A LD A B R A ISLANDS: Caret; A U S TR A LIA: (Q ueensland) G ounam , Unawa, (Torres Strait) Unuwa;
BANGLADESH: Sam udrik kasim; BRAZIL: Tartaruga de pente, Tartaruga imbricada, Tartaruga verdadeira; CARIBBEAN
REGION: Krayoea. Kulalashli; CAYMAN ISLANDS: Hawksbill turtle, (Hybrids), M cQuankie, M cQ ueggie; COLOMBIA:
Carey, Tortuga fina; CO M O RO ISLANDS:Nayamba (male), Nyamba;
CO STA RICA, CUBA, ECUADO R (Peinilla), EL
SALVADOR, ESPAÑA, GUATEM ALA, MEXICO, PANAMA, PERU, PUERTO RICO, VENEZUELA: Carey; CHINA: Kou pi, Tai
mei; EGYPT: Sagl, Sugr; ETIOPIA (Eritrea) Red Sea: Bissa (males), Baga (fem ales); FRANCE: Caret, Tortue d ’écaille,
Tortue im briquée; FIJI: Taku; FRENCH GUIANA: Kala-luwa; GOLD COAST: (Ga) Ayikploto, Halapatadzi, (N zim a )
Apuhuru; G ERM ANY: Echte K arettschildkrote; HAW AII: Ea; INDIA (Tam il Nadu):
A lungam ai, (Andam an Islands)
38
Kangha kac-chua; Tau-da; IN D O C H IN A (BURM A, TH AILAN D , M ALAYSIA, VIET NAM, etc): D o i-m o i, Sat kras;
INDONESIA: Penyu sisik, Sisila pagal; IRIAN-JAYA: W au mis; ITALY: Tartaruga, Imbricata; JAPAN: Tai-m ai; LEEW ARD
ISLAND: Caret; M ALAYSIA: Penyu karah, Penyu sisek; M EXICO (hybrids): M orrocoy; M ICRONESIA: Mu winichen, (Truk
Dist.) W ounlele, (Palau) Ngasech, (Panape) Sapake, (M arshall Islands) Jebake, (Yap Dist.) Darau; M O ZAM BIQUE:
Ingappa; NAMIBIA: Fanohara, Inhama, Taha; PHILIPPINES: Pawikan, Sisikan; POLYNESIA, PAPUA NEW GUINEA: Era,
Fung, Gela, Hara, Lappi, M ahana, Maia, M usana, Purai, Ololo, Opapei, Unawa, Veu, etc.; PORTUGAL: Tartaruga de
pente; SABAH: T ottongan, Sisipangal; SENEG AL: Tortue a écaillés, Tortue tuille; SO UTH AFR IC A: (A fric a a n s )
Valkbekseeskilpad; SRI LANKA: Potu kasvaba, A lunk amai; SUDAN: Abu gudr, Shukeri; SURINAM : Kar’et; THAILAND:
Tao-kra, (Siam Gulf) Con doi-m oi; TON G A: Fonu koloa; UK, USA: Hawkbill, Hawksbill, H aw k’s bill, Tortoise-shell;
VENEZUELA: Parape; YEMEN: Sugr.
Literature : True (1893); Seale (1911); Lewis (1940); Kuriyan (1950); Smith & Taylor (1950); Yañes-A. (1951); Domantay
(1952-3); Hendrickson (1958); Zweifel (1960); Schafer (1962); Donoso-Barros (1964); Carr, Hirt & Ogren (1966); McCann
(1966); Flores (1969); Pritchard (1969, 1977, 1981); Frazier (1971, 1975, 1976, 1979, 1980, 1981, 1984); Bustard (1972);
Ferreira de M. (1972); Kaufm ann (1972); Hughes (1974); McCoy (1974, 1981); Rebel (1974); Carr & S tancyk (1975);
Polunin (1975); Schulz (1975); M cKeown (1977); G arnett & Frazier (1979); Smith & Smith (1980); W itzell (1980, 1983);
W itz e ll & Banner (1980); Chu-Chien (1981); Hughes (1981); Mack, Duplaix & W ells (1981); Nietschm ann (1981); Polunin
& Sum ertha-N. (1981); Ross & Barwani (1981); Sternberg (1981, 1982); Groom bridge (1982); Khan (1982); Potter (1982);
Vonnie (1982); W ood, W ood & C ritchley (1982); Bastian-Fernando (1983); Brooke & G arnett (1983); Frazier & Salas
(1983, 1984); G arduño (1983); Limpus e t al. (1983); M eylan (1983, 1985, 1988, 1989, pers.com .); M rosovski (1983);
Parm enter (1983); M ot-tim er (1984); Pritchard & Trebbau (1984); Bjorndall e t al. (1985); Fretey (1986, 1987); Kamezaki
& Yokuch (1986); C astañeda-A. (1987); Kam ezaki (1986, 1987); Limpus (1 9 8 7 a ,b ); M illiken & Tokunaga (1987);
Schroeder (1987); S chroeder & W arner (1988); Anonym (1989); Duran-N. (1989); M eza-Ch. (1989).
CHEL Lep
Lepidochelys Fitzinger, 1843
Genus : Lepidochelys Fitzinger, 1843, Syst. Rept., Fast. 1, p. 30.
Type Species : Chelonia olivacea Eschscholtz, 1829, Zool. A tla s, 1: 3; by original designation
Synonym s : Caouana Gray, 1844; Colpochelys Garman, 1880.
D iagnostic Features : The ridleys are the sm allest o f the sea turtles. A dults usually have a body m ass o f 30 to 50 kg and
m easure between 55 and 75 cm in straight line carapace length (SCL). In dorsal view, the carapace has a nearly circular
shape, with five or m ore pairs o f lateral scutes, the first one in contact w ith the precentral scute. In the bridge o f the
plastron, each scute bears a pore that is the opening o f the R athke’s gland; carapace usually clean and sm ooth. Head
m edium -sized and subtriangular; m andibles form ing a parrot-like strong, horny beak. Front flippers m edium -sized,
usually w ith one or two (som etim es three) claw s on the a n terior border. In males, the claw s are stronger and more
curved, and the tail is longer; these features are used to grasp the female during mating. Hatchlings have a relatively
longer carapace, and bigger head and flippers than adults. Colour: There is com paratively little variability o f colour
am ong adults o f the same species. Dorsally, L. k e m p ii is plain olive or yellow ish-grey; L. o livacea is slightly darker.
Underneath, both species are cream y-yellow with the flipper m argins darker.
Rem arks : Many authors accept that L epidochelys com prises two species, well characterized by th e ir geographical
distribution, m orphology and behaviour. L. o livacea lives in all tropical and subtropical w a te rs o f the Pacific and
Central A tlantic Oceans, w hile L. kem p ii is indigenous to the G u lf o f Mexico, with seasonally extended incursions to
tem perate w a te rs o f the northw estern A tla n tic Ocean; o ccasionally expatriated in d ivid u a ls a p p ea r also in the
northwestern European waters.
M orphological d iffe re n ce s in the cranial skeleton o f the two sp ecies are easily recognized; furtherm ore, the
scutelation is more constant (5 lateral scutes in L. kem p ii and 5 to 9 - usually 6 to 8, in L. olivacea) and the carapace is
more flat and rounded in L. k e m p ii than in L. olivacea. There are also divergences in diet, and an obvious behavioural
difference is that kem p ii nests during the day and olivacea mostly at night.
Lepidochelys kempii (Garman, 1880)
Figs 32, 33
CHEL Lep 1
Thalassochelys kem pii Garman, 1880, Bull. Mus. Comp. Z ool., 6(6): 123-124 (Gulf o f Mexico).
Synonym s : Colpochelys Kempii. Garman, 1880; Thalassochelys (Colpochelys) kempii. Garman, 1884; Thalassochelys
kempii. Boulenger, 1889; Lepidochelys kempii. Baur, 1890; Lepidochelys kempi. Hay, 1908a; Colpochelys kem pi. Hay,
1908b; Caretta kempi. Siebenrock, 1909; Colpochelys kempi. Deraniyagala, 1939; Lepidochelys olivacea kempii.
Deraniyagala, 1939; L ep ido chelys kem pii. Carr, 1942
39
Subspecies : None.
FAO Names : En - Kemp’s ridley turtle; Fr - Tortue de Kemp; Sp - Tortuga lora.
Fig. 32
m
p re c e n tra l
s c u te
Diagnostic Features : T ogether with its congener,
L. olivacea, Kem p’s ridley is the sm allest o f all
m arine turtles, w ith a body m ass low er than 50
kg. Viewed from above, the carapace o f adults is
nearly round (width o f carapace about 95% o f its
length). The
head
is m od e ra te-size d , subtria n g u la r (head length a b o ut 20% o f total
carapace length). H a tch lin g s have a longer
carapace, w idth about 84% o f total length (SCL),
and a larger head, about 41% o f carapace length
(SCL). D uring grow th, the p ro p o rtio ns o f the
carapace change, and after one year it becom es a
little w ider, (87% S C L ), and the head length
dim inishes to 37% o f the SCL. Head w ith 2 pairs
o f prefrontal scales. Carapace w ith 5 central, 5
pairs o f lateral and 12 pairs o f m arginal scutes;
bridge areas with 4 scutes, each with a pore,
which is the opening o f the R athke’s gland. This
gland releases an o d o riferous substance which
possibly plays a pherom onal role in m aintaining
the integrity o f the m assed nesting assem blage of
fem ales just o ff the beaches, before and during
th e ir arrival. Usually only one visible claw on
fo re flip p e rs ,
h a tc h lin g s
sh o w
tw o;
in
rea r
flippers 1 or 2 claws. Colour: body o f adults plain
o liv e -g re y
d o rs a lly ,
w h ite
or
y e llo w is h
underneath. H a tch lin g s are e n tire ly je t black
w hen w et, but th is changes sig n ifica n tly with
age, and after ten m onths the plastron is nearly
w hite.
1 c la w
c e n tra l
sc u te s
5 la te ra l
s c u te s
m a rg in a l
s c u te s
p re fro n ta l
s ca le s
4 in fra
m a rg in a l
pores
dorsal view of head
plastron
Fig. 33
40
G eographical Distribution : Kem p’s ridley turtle is one
o f the two tu rtle sp e cie s w ith a rath e r restricted
g e o g ra p h ica l d istrib u tio n . The o th e r one is the
fla tb a c k tu rtle
(N a ta to r depressus), co nfined to
northern Australian waters. Both tu rtle s are living in
w arm w aters, w ith in the lim its o f the northern and
southern 20°C isotherm s.
The adults o f Kem p’s ridley turtle usually occur only in
the G u lf o f M exico, but ju v e n ile s and im m ature
in d ivid u a ls range betw een trop ica l and tem perate
coastal areas o f the northw estern A tlantic ocean (Fig.
34). O ccasionally, “w a if juvenile and im m ature tu rtle s
reach northern E uropean w a te rs; th e re are also
several records from further south, i.e. one from Malta
and a few from the M adeira Islands and the Moroccan
coast
R e p o rts
from
o u ts id e
of
th e
n o rm a l
geographical distribution area include an adult female
tagged in Rancho Nuevo, M exico, and encountered
“ nesting” at Santa M arta, M agdalena, Colom bia; th is
seem s to be the first record for nesting o f the species
out o f its prim ary rookery, but there are some doubts
about this record. A second record for nesting o f th is
species out o f its norm al range refers to a turtle that
laid 116 eggs the m orning o f 30 May 1989, on M adeira
beach - St. P e te rsbu rg , Florida, as reported by
b io lo g ists o f the Florida M arine Research Institute.
Nesting has also been observed on Aguada Island,
Cam peche, on the southw estern side o f the G u lf o f
M exico. All records reported for the G reater A n tille s
are p robably m isid e n tifica tio n s o f the olive ridley
turtle, Lepidochelys olivacea.
,0-
20
0-
w
"■
80"
60"
40°
20“
0“
20“
40“
Fig. 34
As in other sea turtles, the hatchlings, after entering the oce an, are rarely seen until they reach juvenile size, i.e. over 20
cm o f SCL. Juveniles usually are more com m on outside t íe G u lf o f M exico, along the east coasts o f the USA, from
Florida to New England, especially o ff Florida and Georgia other spots o f occurrence o f juvenile and im mature ridleys,
quoted in stranding reports, are the w est coast o f Florida : nd the mouth o f the M ississippi River. Kem p’s ridleys found
in New Y ork and M assachusetts (Cape Cod) were carried northward by the G ulf Stream. O ccasionally, some yearlings
and im m ature turtles reach New Foundland waters; such individuals, and also those that have drifted into European
seas may be considered expatriates with little probability
returning to the w estern G u lf o f Mexico and joining the
reproductive population.
Less than fifty years ago, L. kem p ii was the m ost abundant turtle in the G u lf o f Mexico, with populations that were able
to generate “arribazones” estim ated at around 40 000 fem ales on the single nesting beach o f Rancho Nuevo, to the
north o f Tam pico, Tam aulipas, in the western central G u lf o f Mexico (Carr, 1963 and Hildebrand 1963). The m ajority o f
fem ales still come to th is beach to lay th e ir eggs on fresh and windy days, m ostly between April and June. That big
historical aggregation could only have been m aintained by a very large adult population, at least three tim es larger
than the one shown in the film analysed by Carr and by H ildebrand op. cit. It is possible that sim ilar large nesting
a ggregations existed in places w here relevant nesting still occurs today, such as: Playa W ashington and Tepehuaje in
Tam aulipas, Playa Estero G rande and Cabo Rojo (Tam iahua Lagoon) and Tecolutla, in Veracruz; Isla Aguada, in
Cam peche; Padre Island, in Texas, but th is is undocum ented. The original range o f the adult population o f L. kem p ii
included the entire G ulf o f Mexico as a forageing area; nowadays it is still essentially the same, in spite o f the sp ecies’
great decline in abundance. Also, today ju venile and im m ature individuals are more com m only found along the
southeastern coasts o f the United States.
Habitat and B iology : In the G ulf o f Mexico, L. k e m p ii usually inhabits sandy and m uddy bottom s, rich in crustaceans,
w hich are the most com m on item s in the stom ach contents o f subadults and adults. Juveniles frequently are observed
in bays, coastal lagoons and river m ouths; adults are present seasonally in places like the Louisiana coasts and
C am peche Bank, and converge on the Rancho Nuevo nesting ground each spring. Partial m igratory routes for adult
fem ales may be reconstructed from tag-recapture records, on the basis o f the follow ing facts: the tu rtle s rem ain as a
breeding group at least from April to the end o f July; however, individuals may stay near the nesting beach no longer
than a couple o f m onths and are replaced by new individuals; after nesting one or more tim es per season, the fem ales
disappear from the area and do not come back before one or two years; m ales are not com m on around the nesting
41
beach, but can occasionally be seen escorting fem ales or m ating with them near the su rf area, from March to May, but
not throughout the nesting period. It is assum ed that the Kem p’s ridleys follow two m ajor routes: one northward to the
M ississippi area, spread betw een T exas and Alabam a; and the o ther southw ard to the Cam peche Bank. Some
individuals may m igrate beyond these areas, up to w est Florida or to the northeastern side o f the Yucatan Peninsula
around Holbox Islands, w here they remain for the rest o f the year, including w inter. W inter dorm ancy (brum ation) has
been observed in parts o f the range subjected seasonally to low tem peratures, principally C hesapeake Bay, Cape
Canaveral Channel and Florida Bay. The turtles travel near the coast.
At Rancho Nuevo, hatchlings swim directly to offshore currents, w a te r fronts and eddies, searching for concealm ent,
support and food. During this pelagic period, some o f them may be trapped in currents that carry them out o f the G ulf
o f Mexico. Juveniles and im m ature individuals are com m only encountered feeding in shallow w ater, bays and lagoons
o f the eastern coast o f the USA. It is hypothesized that “w hen they reach around 30 cm o f carapace length, they are
strong enough to m igrate back to the nesting beach” . The place, tim e and size at which the tu rtle s undertake the
return travel to the G u lf o f Mexico is uncertain. It has been stated that “ individuals reaching the fartherm ost points, like
European w aters, w ill not be able to m igrate back and consequently w ill be lost to the breeding population” . It is also
said th a t,“w hen some o f these tu rtle s attain ju ve n ile sizes, they w ere reaching the northernm ost point o f th e ir
m igration, and started to make th e ir return southw ard to the rookery in the G u lf o f M exico” . Flence, size, age and sex
m ay be d e te rm in a n ts o f the g e o g ra p h ica l d is trib u tio n o f th e p o p ulatio n .
The m inimum size at m aturity in fem ales o f L. k e m p ii could be 52.4 cm o f straight carapace length (recorded on the
nesting beach). The mean for this param eter undergoes annual variations, which have been quoted to lie between 61.4
and 65.7 cm (1966-1987). At these sizes, and after nesting, the body w eight averages from 32 to 48 kg; for 1988 the
mean body w eight w as 36.7 kg, for a range between 30 and 47 kg (n = 45); the egg clutch usually w eighs around 3.2 kg.
Because o f the Kem p’s ridley’s sm all size and carnivorous behaviour, the age at first m aturity in the wild may be reached
earlier than in other sea turtle species, around 10 to 12 years, but in captivity such age could be reduced to nearly five
years, as was shown in the Cayman Turtle Farm, Ltd., when in April o f 1984 two individuals o f the 1979 year class laid
eggs, w hile in 1989 there were eight mature fem ales laying viable eggs. As a result o f stock ageing, every ye a r the
fertility o f these individuals w as im proved and the survival rate o f the eggs during incubation increased, e.g., by 4.8% in
1984, 14.2% in 1986,30 3% in 1987 (W ood, pers. corn.).
Am ong marine turtles, L. kem p ii is the most conspicuous day-tim e nester, and usually m ass-nesting takes place on windy
days. As nearly the entire adult population nests on a single beach (about 40 km in length, on the w est coast o f the G ulf
o f M exico), the reproductive population could be evaluated very accurately by using tag-recapture data on the beach,
counting all buried nests and num ber o f ovipositions per fem ale and season (1.4 - 1.55 tim es) and the frequency o f
individual interseasonal returns. By using the annual average num ber o f nests laid in Rancho Nuevo during the last
eleven years (1978 to 1988), i.e. 862 nests, together with the above-m entioned param eters, it is possible to calculate the
annual fem ale nesting population at betw een 556 and 615 individuals. The trend o f the to ta l num ber o f nests,
calculated with a linear regression corresponds to an annual average declination o f 1.95% (in 1989). Considering that
about 58% o f the tu rtle s nest every year, the total annual fem ale population could com prise between 790 and 875
individuals, and if the fem ale-m ale ratio is 1: 1, the total adult population in 1988 should have am ounted to between
1 580 and 1 750 individuals. This figure excludes im m ature turtles and sm all breeding groups dispersed between Padre
Island. Texas and Isla Aguada, Cam peche, e.g., the turtles that every year lay around 50 nests in the area between Cabo
Rojo and Tecolutla, in Veracruz State. The data on these groups need to be evaluated quantitatively in order to obtain a
m ore a ccurate a sse ssm e n t o f the total adult pop ulatio n in the G u lf o f M exico.
Kem p’s ridley turtle is a carnivore throughout its life cycle. In the wild, the feeding behaviour o f hatchlings is poorly
known, and very little is known for juveniles. For adults, several reports are available and the principal items in the diet
are crabs (Callinectes, Ovalipes, Hepatus, Areneus, Portunus, Panopeus, Mennipe, and Calappa); shrim ps (Sicyonia and
Penaeus), gastropods, clams, sea urchins, jellyfishes, squid eggs, fishes, vegetable fragm ents, etc. In captivity, these
tu rtle s rea d ily a cce p t ch opped fish, squid, and v e g e ta b le s o r p e lle tize d food. T hey eat m ainly in day tim e.
Predation occurs throughout the ridley’s life-cycle; eggs are predated principally by coyotes, skunks and coaties, ghost
crabs and ants, but when the nest has been opened and abandoned, the rem aining eggs are eaten by vu ltu re s and
boat-tailed grackles. On land, the hatchlings are attacked by the same predators and sea birds; in shallow waters, by sea
birds and bottom fishes such as red snappers, groupers, etc; and in open w aters, by birds and carnivore pelagic fishes
like tunas, m ackerels, jacks, yellow tail, wahoo, barracudas, dolphin fish, sharks, etc. Adult turtles are not eaten by birds
and sm all fishes, but are attacked by large sharks, throughout th e ir lives. Flence, it is com m on to see on the beaches
m utilated turtles, usually w ithout one rear flip p e r or with big w ounds on the rear m argins o f the carapace.
Parasitic problem s and other diseases have not yet been studied in the wild, but it is com m on to observe different kinds
o f flat w orm s in the anterior part o f the intestine. Fibropapillom ae have been detected only once or twice a ye a r in the
course o f the last 23 years o f w ork on the nesting beaches, and only one tim e th is ye a r (1989). Epibionts are not so
com m on; sm all quantities o f barnacles are observed from tim e to time, but never a m assive invasion, as in loggerheads
or leatherback turtles. In fact, the scutes and scales o f the carapace and head o f Kem p’s ridleys are usually clean o f
e p ib io n ts o f any kind.
42
Size : All available data for adults were obtained from the nesting beach o f Rancho Nuevo and its neighbourhood.
Minimum and m aximum carapace lengths (SCL) are 52.4 and 74.8 cm respectively (between 1966 and 1987, n = 4 924).
The annual average length (SCL) o f the carapace between 1972 and 1987 showed a decrease from 67.4 to 65.7 cm; this
may indicate that the mean age in th is breeding population has been d im inishing, probably as a result o f the
enhancem ent w ork done for the last 23 years in the nesting beach and o f a higher m ortality o f adults on the feeding
grounds. Very few data are available for adult m ales; up to now only 9 have been m easured in the above-m entioned
period, and the minimum and m aximum SCL values were 58.5 and 72 cm respectively, with a mean o f 65.6 cm, hence,
very sim ila r to the data for fem ales. There are also only a few m easurem ents o f total body m ass for both sexes,
covering the period from 1966 to 1978: fem ales after oviposition w eighed between 32 and 48 kg, with a mean o f 38.9
kg (n = 281); the mean w eight for 1988 w as 36.7 kg (n = 45), and the w eight o f the egg clutch around 2.45 to 4.08 kg.
The mean w eight o f m ales (n = 8) w as 34.6 kg. In 1966, the body m ass in 17 fem ales ranged from 39 to 49.3 kg, also
a fte r having laid the clutch.
The eggs have the appearance o f ping-pong balls, between 34 and 45 mm in diam eter and from 24 to 40 g in weight.
The female lays about 102 eggs per clutch, 1.4 to 1.55 tim es each season. The Kem p’s ridley hatchlings emerge from the
nests after 45 to 58 days, depending on the w eather (tem perature and humidity). The body m ass in neonates is around
17.2 g, corresponding to an average o f 43.9 mm o f total carapace length.
Interest to Fisheries : Com mercial exploitation o f the Kem p’s ridley sea turtle, is nowadays not officially allowed at any
place o f its geographical distribution range, and consequently no catch is reported in the FAO Yearbook o f Fisheries
Statistics. The K em p’s ridley is restricted to the coastal w aters o f FAO Fishing A reas 31 (west), 21 (southwest), 27
(southeast) and 34 (east), and there is a single record from Area 37 (Malta Island). In the northern and the northeastern
G u lf o f Mexico, this turtle w as com m ercially captured join tly with green and loggerhead tu rtle s up to nearly 15 years
ago. The Kem p’s ridley w as the least desirable, because o f its “poor” flavour. The eggs on the nesting beach were
m assively exploited up to 1965. From 1966 onwards, a total ban w as laid on egg exploitation and in 1977, a decree
declared the Rancho Nuevo nesting beach as a natural reserve. Nowadays, th is turtle is fully protected all along its
range, and it is also included in the Red Databook and considered as an endangered species in Appendix I o f the CITES.
In the Natural Reserve o f Rancho Nuevo, full protection w as started in 1966. From this tim e up to 1977, an average o f
23 000 hatchlings were released each year. From 1978 up to now, as a result o f jo in t efforts o f the US Fish & W ildlife
Service, the US National M arine Fisheries Service and the Fisheries Secretariat o f M exico, the num ber o f annually
released hatchlings has been increased to an average o f 53 000 individuals. In spite o f the trem endous effort m ade to
achieve total protection o f the nesting fem ales and th e ir eggs and hatchlings, and to release increased num bers o f
hatchlings every year, a negative trend o f the population density continues to be observed. Nevertheless, and possibly
as a result o f the above-m entioned program m e, the decreasing annual trend for the num ber o f nests (m ortality)
show ed an upturn from 4.5% (in 1986) to 3.2% (in 1988) and 1.95 % (in 1989).
The fluctuation in the total num ber o f populations and the steady decline o f the adult population may be caused by
the cum ulative effect o f several factors; some o f them may be natural physical phenom ena like hurricanes, storm s,
floods or dry w eather on the nesting beaches, cold stunning in northern grounds and perhaps strong currents that
carry sm all tu rtle s out o f th e ir norm al range o f dispersion; and biological factors such as natural predation, food
scarcity, com petition, disease, etc., all o f them known to be the causes o f natural m ortality. In a natural (undisturbed)
population, such m ortality is com pensated through the natural survival m echanism s o f the species. But if it is not
possible to stop the a dditional, w ide-spread m an-induced m ortality, due to incidental catch by com m ercial and
recreational fishing vessels, blasting o f obsolete oil platform s, ingestion o f debris (plastics), oil pollution, im pacts by
speed boats, deliberate m utilation, entanglem ent by gill-nets, drift-nets and abandoned fishing gears, disturbance o f
nests and nesting a ctivitie s, construction o f barriers, etc., it w ill never be possible to achieve any significant
e n h an ce m e n t o f the K em p’s ridley p o pulation.
W ith regard to incidental captures - one o f the im portant negative m an-induced factors - M arquez et al., (1987) and
M anzella et al., (1988 ms) have estim ated the relative im pact o f various types o f fishing a ctivities upon both adult and
juvenile K em p’s ridleys. They concluded that o f the juveniles, 28% are caught in shrim p trawls, 4% in gill-nets, 6% on
hook-and-line, 1% by dip-nets, 0.8% by swim m ers, 0.2% by beach seines, 0.4% by cast-nets, 0.4% by butterfly nets, and
0.2% by crab pots; another 34% appear as beach strandings, dead or alive, presum ably as a result o f unidentified
fishing activities, and 26% died o f unknown causes. For adults, the figures were 75% in shrim p trawls, 7% in gill-nets,
4% in fish trawls, 1% on hook-and-line, 0.7% in purse seines, 0.7% in beach seines, and 0.7% died o f unknown causes.
However, the data for adults are based e xclusively upon tag returns and there is probably additional m an-induced
m orta lity o f w hich we are unaw are.
Local N am es : CANADA: K em p’s ridley turtle; FRANCE: Tortue bâtarde, Tortue de Kemp, Tortue de Ridley; ITALY:
Tartaruga bastarda; M EXICO: Tortuga cotorra, Tortuga lora; SPAIN: Tortuga bastarda; UK: Bastard turtle, K em p’s
ridley tu rtle ; USA: A tla n tic ridley tu rtle , Bastard tu rtle , K em p’s ridley turtle.
43
Literature : Deraniyagala (1938a.b); Carr (1952, 1957, 1963a); Aguayo (1953); Squires (1954); Bleakney (1955); Carr &
C aldw ell (1958); M ow bray & C aldw ell (1958); W erm uth & M ertens (1961); H ildebrand (1963, 1980, 1981, 1983,
pers.com .); Donoso-B arros (1964a); Chavez, C ontreras & H ernandez (1967, 1968 a,b); C aldwell & Erdman (1969);
Pritchard (1969a,b); Brongersm a (1972, 1981); IUCN (1973, 1976); Pritchard & M arquez (1973); Revel (1974); M arquez
(1976a,b, 1977, 1978, 1981, 1983a, 1984b,c, 1989); Hillestad et al. (1978); Smith & Smith (1979); Carr, Ogren & McVea
(1980); Hendrickson (1980); Lazell (1980); Rabalais & Rabalais (1980); Klima & M cVey (1981); M arquez e t al. (1981,
1985a,b, 1987); Seidel & McVea (1981); G room bridge (1982); Brongersm a & Carr (1983); M rosovsky (1983); W ibbels
(1983); Bacon et al. (1984); Caillouet (1984); M cVey & W ibbels (1984); Pritchard & Trebbau (1984); Am os (1985); Berry
(1985); Byles (1985); Fontaine e t a/. (1985 b); Ogren (1985); O ravetz (1985); Seidel & O ravetz (1985); M arquez &
Bauchot (1987); Schroeder (1987); Manzella et al. (1988); Schroeder & W arner (1988); W ood & W ood (in press).
Lepidochelys olivacea (E schscholtzi 829)
Fig. 35, 36
CHEL Lep 2
Chelonia olivacea Eschscholtz, 1829, Zool. A tla s. 1:3. Type localities: China Sea, M anila Bay and Sum atra.
Synonym s : Testudo m ydas m in o r Suchow, 1798; Chelonia m ulticustata Kuhl, 1820; Chelonia Caretta var. O livacea:
Gray, 1831; C aretta olivacea: Ruppeli, 1835; C helonia (Thalassochelys) olivacea: Fitzinger, 1836; Lepidochelys
olivacea: Fitzinger, 1843; Caouana Ruppellii Gray, 1844; Chelonia subcarinata Ruppeli in Gray, 1844; Caouana olivacea:
Gray, 1844; Chelonia p olyaspis Bleeker, 1857; Lepidochelys dussum ieri Girard, 1858; Lepidochelys olivacea: Girard,
1858; Thalassochelys olivacea: Strauch, 1862; Chelonia dubia Bleeker, 1864; C ephalochelys oceanica Gray, 1873;
Thalassiochelys tarapacona Philippi, 1887; Chelonia olivacea: Velasco, 1892; Thalassochelys tarapacana Philippi, 1899;
Thalassochelys controversa Philippi, 1899; Thalassochelys caretta (part), Gadow, 1899; C aretta rem ivaga Hay, 1908;
Caretta caretta var. olivacea: Deraniyagala, 1930; Caretta caretta o livacea: M. Smith 1931; Lepidochelys olivacea
olivacea: Deraniyagala, 1943; C aretta olivacea olivacea: M ertens, 1952; Lepidochelys olivacea rem ivaga: Schmidt,
1953.
S u b sp ecies : None.
FAO N am es : En - O live rid le y tu rtle ; Fr - T ot-tu e o liv â tre ; Sp - T ortu g a golfina.
Fig. 35
44
Diagnostic Features : The olive ridley turtle has a slightly
deeper body than the Kem p’s ridley. In adults, carapace
nearly round, upturned on the lateral m argins and flat on
top, its w idth 90% o f its length (SCL). Head subtriangular,
m oderate-sized, averaging 22.4% o f straight carapace
length (SCL). H atchlings have relatively bigger heads (39%
SCL) and longer carapaces (width 78% SCL), and also the
flippers are com paratively bigger than in adults. In 3-year
old juveniles, the carapace width is 93% o f SCL and the
head length, 26% o f SCL. Scales and scutes have the same
co n fig ura tio n as in the K em p’s ridley, but the lateral
s cutes are often m ore than five pairs, the first pair is
always in touch with the precentral scute. This species also
has op e ning s o f the R athke’s g lands on the plastral
b ridg e s, th ro u g h a pore on the rea r part o f each
infram arginal scute Fore flippers with one or two visible
claw s on the a n terio r border, and so m e tim e s a n other
sm all claw in the distal part; rear flippers also with two
claws. As in other turtle species, m ales have larger and
more stron g ly curved claws, as w ell as a longer tail.
Colour: adults are plain olive-grey above and cream y or
w hitish, w ith pale grey m argins underneath. Newborn
h atchlings, w hen w et, are a lm ost co m p le te ly black,
som etim es w ith greenish sides, and in general become
dark grey after drying. W ith growth, they change to grey
dorsally and w hite underneath.
G eographic D istribu tio n : This is a pantropical
species, living p rincipa lly in the northern hem i­
sphere, w ith the 20°C isotherm s as its distributional
boundaries (Fig. 37). In continental coastal waters,
w here the m ajor reproductive colonies are found,
these tu rtle s are usually seen in large flo tilla s
travelling between breeding and feeding grounds,
p rincipally in the Eastern Pacific and the Indian
Ocean. In spite o f its wide range o f distribution, this
species is nearly unknown around oceanic islands,
p re c e n tra l
s c u te
1 c la w
5 o r m ore
la te ra l s c u te s
c e n tra
m a rg in a l
s c u te s
p re fro n ta l
4 in fra
m a rg in a l
p o re s
dorsal view of head
plastron
Fig. 36
60“
Fig. 37
45
except for a recent single record from Hawaii. A s in the other species o f sea turtles, there are very few observations on
ju venile and im m ature olive ridley turtles.
It is suspected that oceanic currents are used by adults to travel between th e ir different grounds, but the hatchlings are
dispersed passively by strong currents and transported far from the breeding grounds. Juveniles rem ain hidden until
nearly m aturity; then they are observed approaching the inshore feeding and breeding grounds.
The olive ridley turtle probably w as (and still is) the most abundant o f the w o rld ’s sea
turtles. Nowadays, there are still
several spots o f high concentration w here these tu rtle s arrive seasonally to nest (principally in the Eastern Pacific
Ocean, from Mexico to Costa Rica, on the northeast coast o f India and also in the Atlantic, in Surinam e), or to feed (as
in the region betw een Panam a and Ecuador).
R ecords o f non-breeding olive ridleys, outside the com m on’range o f the 20°C isotherm s, have occurred during warm
weather; e.g. in the course o f the El Niño phenom ena in the eastern Pacific, when L. olivacea has been observed as far
north as the G u lf o f A laska. O ther such records quoted in the literature are from Chile (Arica, Iquique, and the
southernm ost, from Quintero), from the Japan Sea and its southern islands, from the northwest coast o f New Zealand,
and from south o f Q ueensland, Australia, when the w a te r is not cooler than 15°C. These records are m ost comm on
during sum m er. O ther e xtra-territorial, but w arm -w ater records are known from Cuba, Puerto Rico and the eastern
Caribbean islands, and sporadic occurrences have been reported from Bahia and Sergipe in Brazil, w here this species
u su a lly is a bsent.
H abitat and B iology : Outside th e ir nesting areas, the adults o f these tu rtle s are most frequently neritic, travelling or
resting in surface waters, but also obse rva tio n s o f tu rtle s diving and feeding in 200 m deep have been reported.
Basking behaviour on sand beaches is not com m on, but it is not unusual to observe thousands o f olive ridleys floating
ju st in front o f th e ir nesting beaches at about noon tim e. During this kind o f “basking” , the upper part o f the carapace
dries and the turtle has difficulty to dive rapidly, a situation which is used during the
capture and is advantageous for
any predator. It is also com m on to observe birds resting on floating turtles.
This turtle usually m igrates along the continental shelves, and feeds in shallow waters, converging in sum m er and
autum n for nesting on the beaches o f slight slope with fine and m edium - to coarse-grained sand. The nesting beaches
are usually located in isolated areas, some o f them also separated from the m ainland by coastal lagoons. This search for
isolated places and the constitution o f large “arribazones” may have high adaptative significance against predation
and maybe they are the reasons for the generation, w ithin short periods, o f locally restricted populations o f hundreds
o r th o u s a n d s o f fe m a le s and hence, its su cce ss as a b io lo g ica l species.
In the nesting season, the tu rtle s approach special spots on the shore at the beginning o f sum m er; soon afterward,
during the next quarter moon, thousands o f fem ales arrive along a stretch o f several kilom etres o f flat beach (always
less than 10 km). During the “arribazon” , the olive ridley show s a cyclic response to tem perature, so usually there are
no tu rtle s on the beach at noon. In the afternoon, when the sand becom es fresh, the tu rtle s come onto the beach,
increase th e ir num bers up to a m axim um tow ard m idnight, and then start leaving the beach until the next m orning.
Nesting may extend for two or three nights, and usually is repeated every last quarter-m oon until the end o f autumn.
If the “arribazon” is an anti-predation strategy, its selective advantage rem ains doubtful when it occurs on beaches of
restricted length, like Nancite and Ostional in Costa Rica, w here high m ortality o f eggs, em bryos and hatchlings occurs
w hen the fem ales excavate and bury new clutches o f eggs in the sam e spot as the nests o f e a rlier arrivals. Such
m ortality is also com m on on longer beaches because the arrivals occur in m onthly periods and the incubation period o f
the eggs exceeds 50 days.
Because the success o f the hatching o f the eggs laid in subsequent arrivals is low (less than 10%) on small beaches, it is
postulated that the colony is supported by inter-arrival solitary nestings that lay clutches with higher survival rates. On
longer beaches, as in Mexico or India, the survival rate o f eggs is usually over 30%, which m eans that several m illion
hatchlings enter the sea annually. Hence, in the same species, quite d ifferent results are obtained with the same
strategy.
The location o f the m ost im portant breeding grounds is as follows: Eastern Pacific Ocean: western central coast of
M exico, with over 200 000 nests per year (La Escobilla, Morro Ayuta, Chacahua, Piedra de Tlacoyunque and M ism aloyaLa Gloria nesting beaches); w est coast o f Costa Rica (Nancite and O stional), with over 200 000 nests, Nicaragua, with
more than 20 000 nests; Guatem ala, with 3 000 nests, Honduras, with 3 000 nests; and Panama, w ith slightly more than
1 000 nests. W estern Atlantic Ocean: Surinam (Eilanti), with around 2 000 nests; and French Guiana, with less than 500
nests. Eastern Atlantic Ocean: m inor nesting in Angola (Am bris), Skeleton Coast, and northern part o f Namibia, with
around 500 nests. Indo-Pacific region: M ozam bique, several spots, with a total o f no more than 500 nests; India
(M adras and Orissa States - G ahim artha) with the biggest nesting aggregation still present today, annually over 300 000
nests. Eastern Indian Ocean: negligible nesting throughout, but with no more than 1 000 nests per year, especially on
Andam an island and in the southeastern M alaysia peninsula (Kelantan). The species is known up to Japan and eastern
46
Papua New Guinea. O ther seasonal, but not reproductive concentrations, occur in
part o f Venezuela or the area between Colom bia and Ecuador.
feeding localities, like
the eastern
In general, the nesting season is in sum m er and autum n, with variations from place to place: in Mexico and Central
Am erica, it extends from June or July to Novem ber or December, in French Guiana and Guyana, from June to July; in
Surinam , from A pril to S eptem ber, in Cabo Verde and Senegal, from May to August, in northeastern India, from
February to June, in Sri Lanka, from S eptem ber to January, in M alaysia, from A ugust to November, in Burma, from
A u g u st to January, etc.
A s in other species, the olive ridley show s nest-site fidelity, and it is comm on to observe the same turtle nesting several
tim es on the same spot o f the beach, also during subsequent nesting seasons; hence, the reproductive activity o f a
turtle can be followed through several years. But there are also records o f turtles nesting in different beaches, near or
far away from the “original o ne” . W hen the nesting occurs on long beaches, it is com m on to observe tu rtle s shifting
th e ir nesting sites from one section o f the beach to another during the nesting season.
M assive arrivals occur m ostly around each quarter o f the moon (every 14 or 28 days) and are repeated two to seven or
eight tim es each season, but the mean num ber o f nests laid by each turtle usually is no more than 1.5 per season. The
reproductive cycle is nearly annual; over 60% o f the tu rtle s nest every year, 29% every two years and 11% every three
years. In fact, the m ajority o f the fem ale population have an annual schedule but m any individuals shift from one to
another pattern, m aybe as a result o f the quality o f the preceding feeding season and o f the distance covered during
m igrations, so tu rtle s w ith long m igration routes w ill nest every two or m ore years, and non-m igratory individuals
(residents), w ill be able to nest each year. The num ber o f eggs laid by each turtle ranges from a couple o f dozen to
more than 155; sm all clutches may be the result o f interrupted nesting or may be the last nest made by this turtle in the
season. The mean num ber in a clutch usually is around 109 eggs, but there are significative variations am ong localities,
e.g., in Mexico, 105.3 eggs (n = 1 120 nests); Flonduras, 108.3 eggs (n = 50 nests); Costa Rica (Nancite), 105 eggs (n = 20
nests); Surinam, 116 eggs (n = 1 154 nests); British Guiana, 167 eggs (n = 50 nests); Oman, 118 eggs (n = no data); India,
113 eggs (n=9).
The mean diam eter o f the egg is rather sim ilar am ong different populations, usually ranging from 32.1 to 44.7 mm and
from 30 to 38 g in weight. Hatchlings are between 34.7 and 44.6 mm o f SCL and from 12 to 22.3 g in body weight.
For exam ple, in M e xico , the mean egg size ranges from 39.1 to 40.6 mm (n = 7 clutches, 757 eggs), in H o n d u ra s , 37.5 mm (n = 50 eggs), in S u rin a m ,
42 mm (n = 116 eggs), in B ritis h G uiana, 39.5 mm (n = 50 eggs); in A n d a m a n Is la n d s , 39 mm (n = 51 eggs), and in India, Gahim artha, 37.5 mm (n =90
eggs). The mean egg m ass or w eight also shows variations, but is usually around 30.1 to 38.2 g. The carapace size (SCL) o f the hatchling also varies, but
in general the m ean value lies between 39 and 42 mm; in M e x ic o , the m ean is around 39 mm, with a range usually between 37 and 42 mm (n = 329);
in S o u th A frlc a , 43.9 mm, with a range between 42.9 and 44.6 mm (n = 5); in B ritis h G uiana, 41 mm (n =4); in India, 39.4.m m with a range from 34.7 to
42.9. The mean body m ass o f the hatchling varies between 15 to 19 g, in M e x ic o it is nearly to 14 g, w ith a range from 12 to 21.5 g fo r viable turtles
(n = 329); In S o u th A fric a , 19.5 g with a range from 16.8 to 22.3 g (n = 5); in In d ia , 16.72 g, with a ranges from 12 to 19.5 g (n = 200).
The incubation period o f the egg clutch usually extends from 45 to 65 days, and is strongly correlated with tem perature
and humidity; in dry and cold weather, it lasts longer than under optim al tem perature and hum idity conditions, around
3 0 °C and 14% respectively. O ther param eters that influence the length o f the incubation period are: sand grain size,
organic m atter content, clutch size, date o f oviposition, and possibly, the proxim ity to other nests (arrival conditions). A
s h o rte r incubation period reduces the possib ilitie s for predation and the detrim ental e ffe cts o f bad w eather. It is
difficult to indicate precisely the duration o f the incubation period for each nesting beach, but it generally runs w ithin
the above-quoted range. In Escobilla, Mexico, it changes along w ith the season, with a m inim um duration for nests laid
between A ugust and S eptem ber (around 47 to 58 days); in northern beaches like Sinaloa, it lasts between 49 and 62
days, in Surinam , 49 to 62 days (n = 22); in A ustralia, 48 to 51 days, and in India, 50 to 62 days. In captivity, the
incubation usually lasts longer, and the sex ratio obtained may be biassed to males.
The age at m aturity for the olive ridley is, as in the m ajority o f other sea turtles, uncertain; since it is one o f the sm allest
species, it must mature earlier, possibly at average sizes o f 62 cm o f SCL. V ariations should occur with latitudinal range
o f distribution, quality o f the food, size o f the population (com petition) and genetic factors. The sm allest m ature size
o b se rve d in La E scobilla, M exico, w a s a fe m a le o f 49 cm (SCL).
C ourtship in this
species is not often observed. M ating is perform ed
routes, and occurs principally at the sea surface; the coupling pair
partners usually swim separately. A s in other species, the male holds
four flippers, and
m ating may last for a few m inutes to several hours.
M ultiple m ating o f a fem ale, by several m ales, may occur but has not yet
near the nesting beaches or along the m igratory
may dive if disturbed, and soon afterw ard the
the carapace o f the fem ale with the claw s o f his
It occurs before
and during the nesting season.
been reported.
Because nesting usually is perform ed through arriva ls o f very large aggre g a tio n s o f fem ales, the incubation and
hatchout also occur m assively and w ithin w ell-defined periods. Depending on the w eather conditions at the tim e o f the
arrival, the incubation period and hatchout w ill show different characteristics. If at these tim es the w eather is dry and
cold, the sex rate o f hatchlings may be biassed to m ales or to fem ales and the success o f the incubation substantially
47
reduced. The incubation co n d itio ns change abruptly from arrival to arrival, and they are m ainly dependant on
tem perature and hum idity. It has been found that a normal sex rate o f 1:1 is obtained under incubation tem peratures
o f around 30°C, with very sm all variations between populations. In olive ridleys, m ales are predom inant at 28°C and
fem ales at 32°C. Tem peratures outside th is range not only affect the sex-ratio, but also lead to a decrease o f the
survival rate.
Hatching success is affected by direct and indirect disturbance o f the beach by man, storm s, floods, erosion, dryness,
sand com pactation, fungus and bacterial invasion and predation. The tim e o f day at which hatchlings em erge may
affect th e ir survival rate; usually they leave the nest between afternoon and early m orning; outside o f th is tim e-span
they are more easily predated, or dried by the sun and hot sand before reaching the s u rf zone. Predation occurs in
day-tim e and at night; during the day by m any kinds o f b irds and m am m als th a t are visu a lly attracted to the
contrasting colours o f the tu rtle s (black bodies against w hitish sand), and all hatchlings o f a clutch may easily be
devoured before they reach the sea. A t night, predation dim inishes, but is accom plished by nocturnal m am m als, like
jaguars, ja guaroundis, raccoons, opossum s, jackals, hyaenas, feral dogs and pigs. O ther predators o f eggs and
hatchlings are m onitor lizards ( Varanus) in Asia, and caim ans (Paleosuchus palpebrosus and Caym an crocodilus) and
even racer snakes in the Guianas. One predator alw ays present is the ghost crab, and there usually are thousands o f
these crabs roam ing perm anently on such beaches. In the sea, the hatchlings are eaten by sea birds and carnivorous
fishes. On beaches o f western Mexico, individual frigate birds (Fregata m agnificens), are capable o f sw allowing up to
six ridley hatchlings every morning, an activity that w as photographed by S. Cornelius on the beach o f Nancite, Costa
Rica.
Predation at stages other than eggs, hatchlings or adults has been the object o f much speculation. Large fishes and
sm all sharks are capable o f eating juveniles, but subadult and adult turtles are eaten in the sea only by sharks. Adults
on the nesting beaches can be killed by dogs and in some areas also by hyaenas, jackals, jaguars and tigers. However,
predation by fe lines is dim inishing rapidly nowadays.
The olive ridley is a facultative carnivore, which for long periods is capable o f eating a single kind o f food, such as red
lobsterets (P leuroncodes planipes), e.g. on the w est coast o f Baja California.In other places, it may take a variety o f
food, e.g. o ff Oaxaca, southern M exico, w here a study, carried out from July to D ecem ber (1982) showed that adult
m ales (n=24) fed m ainly on fishes (57% ). salps (38% ), crustaceans (2%) and m olluscs (2%). and the diet o f adult
fem ales (n = 115) included salps (58%), fishes (13%), m olluscs (1 1%), algae (6%), crustaceans (6%), bryozoans (0.6%).
sea s q u irts (0.1% ), s ip u n cu lid w o rm s (0.05% ), and fish e g g s (0.04% ).
The large va riety o f food item s in the olive rid le y's diet is w ell docum ented in data gathered from the a n a lysis o f
stom ach contents o f turtles in Mexico: gastropods, 9 species, (e.g., Polinices, Turritella)', neogastropods, 26 species
(e.g., Persicula, Strom bina, Conus, Terebra, Polystira), pelecypods, Veneroidea, 17 species (e.g., Pitar, Tivela, Chione,
N em ocardium , Nuculana)', scaphopods, (D entalium ); crustaceans: am phipods, isopods, stom atopods (Squilla),
decapods (fragm ents); bryozoans; chordates: ascidans (sea squirts), Thaliacea (salps); vertebrates: fishes (Sphoeroides
and undeterm ined fragm ents o f fish bones) and egg m asses o f fishes (probably eels and sardines), and unidentified
algae. In another report (6 turtles) food item s include bentonic fauna, such as: crustaceans (isopods and decapods:
Portunidae, Paguridae); m olluscs (bivalves and gastropods), and nectonic fauna i.e.: je llyfish e s and chaetognaths.
During m igration in the open sea, olive ridleys have been sighted feeding on red lobsterets (galateids) on the western
side o f Baja C alifornia, and on floating egg clusters, probably o f flying fishes, o ff Colom bia.
Size : The mean straight carapace length (SCL) o f mature olive ridleys, m ostly collected from com m ercial catches,
ranges between 51 and 75 cm, with an average o f 67.6 cm (n = 844) for both sexes. In general, adult m ales have around
3 cm more o f carapace length and nearly 2 kg less weight than fem ales; th is difference is because the fem ale has a
d eeper body than the m ale, even though the latter has a longer carapace. The mean carapace length (SCL) changes
from ye a r to year, but alw ays w ithin the observed limits.
For exam ple: in M exico (Escobilla), from 49 to 71 cm, with a mean o f 60.6 cm (n = 1 563); in Costa Rica (Nancite), from 57 to 72.5 cm with a mean of
65.2 cm (n = 53), in H onduras, from 58.5 to 75 cm; in G uyana, a mean o f 68.1 (n = 14); Surinam , from 63 to 75 cm, with a mean o f 68.5 cm (n = 500);
South East Africa, from 63.3 and 67.5 cm (n = 2); M ozam bique, from 58.1 to 69.5 cm , with a mean o f 65.4 cm (n = 5); M adagascar, from 52.8 to 66.5
cm , with a mean o f 60.6 cm (n=21); Sultanate o f Om an, from 69.9 to 72.1 cm , with a m ean o f 71.5 (n = 100); India (Gahim artha), from 57 to 71 cm,
w ith a mean o f 64.3 cm (n = 55), o ther m easurem ents in fem ales give 65 to 75 cm with a mean o f 72.9 (n = 108) and possibly the last m easurem ents
w ere m ade over the curve o f the carapace (CCL); Sri Lanka, from 68 to 79 cm (n = no data) possibly m ade over the curve o f the carapace (CCL). In
C olom bia, a sam ple obtained from incidental bycatch o f shrim p traw ling (D uque-G oodm an, pers. com .) ranged from 52 to 75 cm , with a mean o f 63.1
cm (n = 50) fo r both sexes.
C om m only the body m ass va ries from 33 to 4 3 .4 kg, w ith a mean o f 38.1 kg (n = 193).
Som e data on body m ass are available from the literature, e.g., M exico (O axaca-E scobilla), m ean w eight fo r fem ales: 39.25 kg (n = 136) and fo r
males: 36.8 kg (n = 51); in Surinam , mean w eight for both sexes: 35.7 kg (n = 14); in India (Gahim artha), mean weight for both sexes: 43.4 kg (n = 55).
and for females, (1985): from 32 to48 kg, with a mean o f 49.5 kg (n = 108).
48
Interest to Fisheries : The olive ridley is still today the m ost abundant sea turtle o f the world
illegally throughout its distribution range. Up to the end o f the seventies, the leather m arket
with the hides o f this species, and today the leather traffic continues, but on a sm aller scale.
turtle yie ld s 25% o f its total body w eight in meat, in addition to oil, and if industrialized,
protein and residual fertilizer.
and is captured legally or
w as abundantly supplied
Besides o f the hides, this
it provides a high-quality
These are the reasons for the high value o f this species and for its rapid depletion on the m ajority o f breeding and
feeding grounds. Egg exploitation w as developed in pre-historical tim es, but has been increased in the last century to
da n ge ro u s levels that are th re a te n in g several po p ulatio n s w ith extinction.
Harvesting o f eggs continues in the m ajority
quotas, e.g., in M alaysia, Surinam, Honduras;
areas. Hence, the worldw ide annual harvest
egg harvesting are in vogue, and the turtle
m entioned countries.
o f the nesting grounds: in some parts it is legalized and subjected to
in others it is illegal, e.g., in Mexico, Costa Rica, India and other nesting
m ust am ount to several m illions o f eggs. Nowadays, cam paigns against
cam ps for nesting protection also are increasing in all o f the above-
The capture o f adults today may be directed or incidental, legal or illegal. In the case o f developed fisheries, olive
ridleys are usually captured on the breeding or feeding grounds, using sm all fiberglass or w ooden boats with 40 HP
outboard gasoline m otors. The crew in general is form ed by two fisherm en, one o f whom throw s over the turtle and
carries it up to the boat, w hile the oth er directs the boat and assists in hauling the anim al on deck. T his fishery is
perform ed in the early morning, w hen the tu rtle s are lazily floating in the sunshine, solitarily or in couples; under these
conditions, they are unable to dive rapidly. At the height o f the season each crew may capture over 40 individuals in a
morning. Olive ridley turtles are also captured with m onofilam ent nylon nets o f 25-35 cm stretched mesh, usually over
500 m length and 4 m deep, with few leads, to avoid drow ning the turtles. Such nets are sim ilar to those used for
sharks, and often they are a ctually registered for shark fishing, but used to catch turtles.
No separate official catch data are recorded for this species in the FAO Yearbook o f Fishery Statistics. General catch
statistics for unidentified marine tu rtle s (doubtless including this species) are provided for Fishing Areas 77 - Eastern
Central Pacific (305 m etric tons in 1987) and 87 - South East Pacific (864 m etric tons in 1987). In Area 77, Mexico is the
main exploiting country (859 m etric to n s in 1987), w hile Ecuador and Panama take only insignificant quantities. In
Area 87, the entire reported catch corresponds to Peru, but includes leatherbacks, olive ridleys and green turtles. By
converting the mean total weight data, it w as possible to estim ate the total num ber o f individuals captured in 1985 at
more than 25 000 in Mexico and at about 1 000 in Peru. The worldwide annual catch is doubtless much higher, since no
inform ation is available from a large part o f the Pacific coast o f Central Am erica and Colom bia. National statistics from
Ecuador, Instituto Nacional de la Pesca, indicate that between 1978 and 1981, an average num ber o f 80 000 turtles
w ere captured annually; after 1981, the capture w as reduced substantially everyw here because o f the signature o f
CITES by m any countries. Until that year, the principal im porters o f skin and leather were Italy, Japan, Switzerland,
France and M exico.
The species is also caught on the northeasterncoast o f South Am erica and in the eastern Indo-P acific region. The
incidental capture o f olive ridleys by shrim p traw lers, long-liners and purse-seiners is generally not reported and may
am ount to several thousand tu rtle s each year.
Local N am es : AND AM AN ISLANDS: Gadha kacchua; ARABIAN RED SEA: Bage; BANGLADESH: Sam udrick-kasim ;
BRAZIL: Sibirro; CAR IBBEAN: Kulalashi; COLOM BIA: Golfina, Lora; COSTA RICA: Carpintera, Lora; EL SALVADO R:
Golfina, Lora; ETHIO PIA (ERITREA): Bage; FRANCE: Tortue bâtarde, Tortue de Kemp, Tortue de Ridley, Tortue olivâtre;
FRENCH GUIANA: Kula-lasi; G UATEM ALA: Parlama; GULF OF SIAM: Condit; G UYANA: Tera-kui; INDIA (Tamil):
Shitam ai; INDOCHINA: Quan dong; INDONESIA: Penyu algu-abu; ITALY: Tartaruga bastarda; JAPAN: Him e-um igane;
M ALAYSIA: Penyu lipas; M EXICO: Cahuama, Golfina; NEW GUINEA: Ahulam , Bung, Mabua, M akabni; NICARAGUA:
Paslam a; PANAMA: Tortuga m ulato; PERU: Pica de loro; PHILIPPINES: Powikan; PO LYNESIA: Aonana, M okabu,
Pimbat; PO RTUG AL: Tartaruga; SENEG AL: Tortue de roches, Tortue olive; SOUTH AFRICA: Oulo, Ouzo, Xicove
(AFRICAANS): O lifkeurige Ridley, Seeskilpad; SPAIN: Tortuga bastarda, Tortuga de Kemp; SRI-LANKA: Batu casbaw,
Mada casbaw; SUR IN AM : W arana; THAILAND: Tao-ya; TON G A: Tuangange; VENEZUELA: Bestia, Loba, Tortuga
m anila; VIE TN A M : Guan dong, Lemech; UK, USA: O live ridley, Pacific ridley.
Literature : Poulain (1941); O liver (1946); Yáñez, A. (1951); Aguayo (1953); S chaefer (1962); Pritchard (1966, 1969);
H ughes & M entis (1967a. b); C aldwell (1969); Flares (1969); M arquez (1970, 1977, 1978, 1981, 1984); Ferreira de
M enezes (1972); Hughes (1974); Varona (1974); Phasuk & Rongm uangsart (1973); Honma & Yoshie (1975); Schulz
(1969, 1975); C ornelius (1976); M arquez et al. (1976, 1981), Zwinenberg (1976); Hubbs (1977); Smith & Smith (1979);
C asas-Andreu & G om ez-Aguirre (1980); Frazier (1980, 1983); Limpus, M iller & Fleay (1981); Stenberg (1981); Khan
(1892); M arquez & van Dissel (1982); Rajagopalan & Bastian-Fernando (1983, 1985); Frazier & Salas (1982, 1983, 1984);
M ohanty-Hejm andy & Dimond (1985, 1986); R esales-Loessener (1985); Fretey (1986); M ontenegro et al. (1986); AcuñaM esen (1988); Stinson (1989); Hildebrand (pers.com .).
CHE
N a ta to r M cculloch, 1908
Nat
Genus : W a fa fo rM cC u llo ch , 1908, Rec. A u st. M us. 7 (2 ): 12 6 -1 2 8
Type Species : N atato r tessellatus M cculloch, 1908 [= Chelonia depressa Garman, 1880], Bull. Mus. Comp. Zool.
126; by m onotypy.
6: 123-
Synonym s : C helonia Linnaeus, 1758; C helone Boulenger, 1889.
Diagnostic Features : See species.
Rem arks : This is a m onotypic genus. The only species, N a tato r depressus, w as previously included in the genus
Chelonia, but several a u tho rs had q u e stioned th is ta xo n o m ic status.
Follow ing a review o f the o riginal d e scrip tio n s o f C h elo nia dep ressa and N a ta to r tesselatus,
redescribed as Natator depressus (Garman, 1880) by Limpus et al., 1988 and Zangerl et al., 1988.
Natator depressus (Garman, 1880)
the
species w as
CHE N at 1
Fig. 38
Chelonia depressa G arm an, 1880, Bull. Mus. Com p. Z ool. 6: 123-6, (E ast Indian Ocean and North A u stra lia n w aters)
Synonym s : Chelonia ja p o n ic a Thunberg, 1787; C helone m ydas: Boulenger, 1889 (in part); C helonia depressa: Baur,
1890; N a tato r tessellatu s M ccu llo ch , 1908; C h elo nia m ydas ja p o n ic a : W erm uth & M ertens, 1961.
Subspecies : None.
FAO N a m e s : En - Flatback turtle; Fr - Tortue Platte; Sp - Tortuga plana de Australia.
in te rg u la r
s c u te s
4 in fra ­
m a rg in a l
> s c u te s
w ith o u t
p o re s
dorsal view
1 p a ir o f
p re fro n ta l s ca le s
ventral view
50
Diagnostic Features : A m edium -sized species, with very special m orphological features. In the adult, the body is flat
and the carapace sm ooth, nearly elliptical, with upturned margins; in subadults, the carapace rim is usually indented
from the middle part backward. Carapace width (n = 14) from 82 to 84% o f carapace length (CCL). Head m edium -sized,
subtriangular, flat on top, sim ila r to th a t o f Lepidochelys, w ith a m oderately serrated low er tom ium . O verall
scutellation sim ilar to that o f the Chelonia group (5 central, 4 pairs o f lateral and 12 pairs o f m arginal scutes), but the
carapace feels soft, waxy and sm ooth and is usually free o f barnacles. Head scales also generally sim ilar to those o f the
Chelonia group, but consistently 3 post-orbitals at each side (4-4 in Ch. mydas), and prefrontals w ithout (or with very
lim ited) contact with the sheath o f the upper tom ium ; som etim es, an extra-preorbital (preocular) scale on each side.
Snout longer than in Ch. m ydas and nearly equal to length o f orbit. Ventrally, the scutes have the same counts as in Ch.
m ydas (6 pairs o f main scutes, one intergular scute, often a pair o f postanal scutes, and 4 poreless infram arginal scutes
in each bridge); there is only one axillary scale in each bridge. Each flipper has a single visible claw (in young individuals,
an extra distal claw is present, more apparent in the fore flippers) and the scales o f the fore and rear flippers are
interrupted by w rinkled skin overlying the phalanges. Colour: adults dorsally dull
olive-grey, with pale brownishyellow tones m arginally; neck and head with the same pale tonality. Ventrally the plastron, side o f neck and proxim al
part o f the flippers are cream y w h ite . Young individuals are more brightly coloured. The colour o f hatchlings is quite
distinct from any other sea turtle hatchlings; the carapace scutes form a dark grey reticulate pattern, each scute with a
pale olive grey centre and the entire rim o f the carapace and flippers is contoured by a cream -coloured band. Ventrally,
the hatchlings
spot.
are cream -white, except along the central
G eographical D istribution : The flatback turtle is
in d ig e n ou s to the
n o rth w e ste rn ,
northern
and
n o rth e a ste rn reg io n s o f A u stra lia (Fig. 39). It
occurs com m only in shallow w aters, especially in
coastal a re a s along the m ain coral reefs (G reat
B a rrier Reef) and in the v ic in ity o f co n tinental
isla n d s, from 21 °S in the w e st to 254 in the
sourthern part o f Q ueensland, which includes the
southern coastal w a te rs o f the T im or and Arafura
seas. Single in dividuals have been reported from
the so u the a ste rn coasts o f P apua/N ew G uinea
through incidental capture by prawn traw lers, but
no nesting o r m ature fem ales (with w h ite-shelled
eggs) have been reported from these coasts. There
are several rep o rts from outside the A u stra lia n
region, but these records represent m is id e n tification, e.g.: Deraniyagala (1939) suspects that the
fla tb a c k stra y s into Sri Lankan w aters; G arm an
(1908) quotes its incidence on Easter Island in his
“check list o f reptiles” for that locality.
part
o f each flipper, which is stained by
a bluish-grey diffuse
0°
-----------
*
A
\
20°
iV
40°
v.S'
r
V
100°
120°
140°
C
160°
0
180°
Fig.
39
H abitat and Biology : N a ta to r depressus is the sea turtle with the m ost restricted distributional range. It seem s to be
com pletely neritic and endem ic to shallow w aters o f Australia. This species apparently has a very low em igration rate
out from its m ajor distribution area and does not go beyond the continental shelf. It m oves between the nesting
grounds on the m ainland and on islands, and the feeding grounds in shallow w aters o f north-eastern Australia and in
the G ulf o f Carpentaria. Distances covered by tagged turtles are between 215 and 1 300 km.
Nesting o f the flatback turtle occurs along the northern coast o f Australia, from Port Hedland (20°S) in the w est to Mon
Repos (25°S) in the east. In W estern Australia, Delam bre Island (located on the northwestern shelf) has been reported
as an im portant nesting ground. In the Northern Territory, Greenhill Island appears to be the m ost significant rookery
for the northw estern coast, w hile low -density nesting occurs throughout the state; on the w estern side o f the G u lf o f
Carpentaria, w hich is part o f the Northern Territory, the Sir Edward Pellew Island w as reported as an im portant nesting
area; and in the northeastern part o f the Gulf, Crab Island appears to be the m ost im portant rookery for the species
throughout Q ueensland and possibly for the entire range o f distribution, with several thousand nesting fem ales per
season. On the eastern coast o f Queensland, between Cape Y ork (11 °S) and Townsville (19°S) nesting is negligible or
absent; there are several nesting points on the continent, from Tow nsville to Mon Repos (25°S) such as: Langham
(22°S), Rocky Point (24.5°S) and Mon Repos; and on the nearby islands, such as: W ild duck and Avoid Island (22°S), Peak
Island (23°S), Curtis and Facing Island (24°S); each o f these nesting places supports an annual population o f up to
several hundred turtles.
51
The peak o f the nesting season varies from one place to another; in southeastern Q ueensland, the flatback nests only
in the sum m er m onths, from Novem ber to January, while on the northern beaches nesting occurs throughout the year,
w ith a peak between March and April. On Crab Island, the main nesting period goes from A ugust to October. In these
rookeries, the nesting o f other species besides N a tato r d epressus is apparently rare, but even if it occurs, interference
with the fla tb ack seem s to be m inim ized by the natural shift in tim e o f the respective seasons and location
o f the
nesting sites. No other place outside northern Australia has been reported as nesting ground for the flatback.
A dult flatback fem ales show strong philopatric ca pabilities in successive
seasons. False crawls for nesting attempts are uncommon for this turtle.
nestings w ithin
the same
and
indifferent
At Mon Repos, the renesting interval for subsequent reproductive seasons ranges from 1 to 5 years, with a mean o f 2.65
years (n = 40). W ithin a breeding season, the renesting interval observed for flatbacks ranges from 12 to 23 days, with a
mean o f 16 days, they lay from 1 to 4 successive tim es, producing a mean o f 2.8 clutches per season. The num ber o f eggs
per clutch is less than half o f that recorded for the other species o f Cheloniidae, but the size o f the eggs is quite large,
com parable to that in Derm ochelys. The m ean num ber o f eggs per clutch is about the same in the northern part o f the
range, e.g. Crab Island: 56.2 eggs (range, 22 - 76, for n = 76 nests) and in the eastern part, e.g. Mon Repos: 50.2 eggs
(range, 7 to 73, for n = 87 nests). The mean size o f the eggs is 50.6 mm for Crab Island and 52 mm for Mon Repos (range,
46.6 to 54 mm, for n = 310 and 47.5 to 56 mm, for n = 250, respectively). The mean egg m ass in the above-m entioned
places is 72.7 and 77.8 g (50 to 83.5 g, for n = 238 and 63.5 to 86.7 g, for n = 220, respectively).
The hatchlings o f N a tato r depressus are bigger than those o f Chelonia, but sm aller than those o f Derm ochelys. For
Crab Island and Mon Repos, the m easurem ents are respectively:
59.7 mm o f SCL (range, 53.9 to 66.5 mm for n= 211).
and 61.2 mm o f SCL (range, 56.6 to 65.5 mm, for n = 190); the weights are 45.1 g (range, 40.5 to 51.5 g, for n = 40) and
43.6 g (range, 33.3 to 49.1 g, for n = 190). respectively. All these m easurem ents were obtained from random sam pling
o f several clutches gathered on both o f the studied beaches.
Age at first m aturity has not been determ ined for the flatback but, possibly because o f its protein-rich diet, this species
may reach m aturity at a younger age than the vegetarian green turtles Chelonia m ydas and Chelonia agassizii.
Predation occurs throughout the life-cycle, but reaches its highest values during incubation, which lasts from 47 to 58
days (mean o f 53.4 days for Mon Repos beach). In South Q ueensland, the eggs are eaten by introduced foxes ( Vulpes
vulpes), dingos, rats and goannas or m onitor lizards (Varanus), the latter being the m ost pernicious predators on
m ainland beaches, but this reptile is also present on several islands o f the region. Com m only, ghost crabs ( Ocypode)
invade the nests and destroy between 1 and 6% o f each clutch. W hen storm s and typhoons coincide with the peak o f
the nesting period, floods and erosion produce massive m ortalities. Eggs are also eaten by man, as on Crab Islands (see
section “ Interest to fish e rie s”). The hatchlings are vulnerable to terrestial predators, e specially w hen they emerge
from the nest and cross over the beach to the surf. The flatback, because o f its size, apparently is big enough to avoid
m ost ghost-crab attacks. During the night, hatchlings are assaulted by rufous night herons (N yctico rax), which are
capable o f killing up to 100% o f the clutch. The few hatchlings that escape from the nest during daylight are predated
by diurnal birds such as the black-necked stork (X enorhynchus), the w hite-belly sea eagle (H aliaetus), the brahm iny
and the whistling kite (Halliastur) and the osprey (Pandion). Offshore hatchling predation has not yet been quantified,
but A ustralian pelicans (Pelecanus) were observed after some daylight em ergences o f hatchlings, and when disturbed
at roost, they regurgitated as many as eight freshly ingested baby flatbacks. Once in the sea, hatchlings are easy prey o f
any carnivore anim als large enough to sw allow them, such as fishes, especially sharks, which threaten them throughout
their lives. The adults, principally fem ales when landing to nest, are easy prey, e.g. o f crocodiles (Crocodilus porosus), as
w as recorded from Crab island beach.
Feeding grounds and food are nearly unknown for the hatchling and ju venile stages o f the species. The carnivorous
adults inhabit inshore turbid w aters o f the entire Australian continental shelf, except the southern coasts. The flatback
is described as a carnivorous forager like Caretta and Lepidochelys, because o f its short flippers and broad skull. There
are several reports o f stom achs containing brown algae and squids, or filled with “trep a n g ” , sea cucum bers o f the
genera A ctin o pyga and Holothuria', other benthic anim als included in the diet are hydroids, soft corals (alcyonarians),
and m olluscs. A report on stom ach contents o f two im m ature (14 and 22 cm o f SCL) fla tb acks includes jellyfish,
gastropods, bivalves and cephalopods (sepiids).
Size : The available m easurem ents are confined to nesting fem ales from the southeast Q ueensland and Crab Island
nesting beaches. The southeastern Queensland tu rtle s (n = 14) m easured in curved carapace length (CCL), from 88 to 96
cm, (mean 92.3 cm), and the mean w idth w as 77.8 cm, with a range o f 72 to 81 cm. The nesting turtles (n = 326) from
Crab Island m easured from 80.5 to 97 cm (CCL) (mean 89.5 cm). The mean body weight for Queensland (n = 10) w as 74.4
kg; the variation for the individuals (n = 28) from Crab Island w as 59.5 to 84 kg, (mean o f 71 kg).
52
Interest to Fisheries : Very little inform ation exists on this subject. Because the catch is negligible for world statistical
purposes, this species is not recorded in the FAO Y earbook o f Fisheries Statistics. The flatback is restricted to the coastal
w aters o f the northeastern part o f Fishing Area 57, the central-southern part o f Fishing Area 71 and the northwestern
part o f Area 81. This turtle has never been favoured as food by the aborigines or Europeans. Lim pus (1978) and others
report that, because o f its “carnivorous” diet, the meat o f the flatback turtle is disagreeable in taste. Annually, only a
few turtles, principally fem ales from the Crab Island rookery, are collected and sold to residents o f Thursday
Islands.
The eggs are more appreciated by the residents o f Bamaga and Thursday Islands, who regularly visit Crab Island to
harvest them , principally for private consum ption.
The species is recognized o f value for subsistence use, but in the G ulf o f Papua, during prawn trawling, several turtles
per ye a r are captured incidentally; also in the G ulf o f Carpentaria and Shark Bay, flatbacks are quite often caught by
the same type o f fishing gear and by large-m eshed set-nets, but again no statistical figures are available on these
c a tc h e s .
There is no inform ation about the use o f specialized fishing gear to catch flatbacks; the capture is m ainly incidental,
except for those caught on Crab Island by the Bam aga residents and the indigenous com m unities o f northern and
northeastern Q ueensland. Local consum ption is low because some people consider the flatback m eat as poisonous. In
Torres S traits and North Q ueensland, there is a harpoon fishery for the green turtle and it is possible that some
flatbacks are captured as bycatch in the form er area, but no statistical data are available. Historically, the remora or
sucking fish (Echeneis naucrates) w as used as a m ethod to capture sm aller turtles (principally greens); follow ing the
attachm ent o f a tethered fish to the tu rtle ’s carapace, it can be hauled to the canoe. If the turtle is large, the fish is
used only as a detector for the purpose o f reaching the turtle by diving, by follow ing the line. Som etim es, the struggle
o f the anim al protracts itse lf for several hours before it can be hauled to the canoe.
Local Names : AUSTRALIA, NEW ZEALAND: Flatback turtle; PAPUA NEW GUINEA
Daugo Islands): Kikila, (Paredaba village): Usi vidi.
-
Central
Province
(F isherm en’s/
Literature : Boulenger (1889); Baur (1890); G arm an (1908); G udger (1919); W erm uth & M ertens (1961); W illiam s,
Grandison & Carr (1967); Bustard & Limpus (1969);
Limpus (1971, 1978, 1980, 1981, 1986, pers.com .); Bustard (1969,
1972); Pritchard (1979); Rhodin, Spring
& Pritchard (1980); Spring (1981);
Limpus, Parm enter, Baker & Fleay (1983,
1983a); M rosovsky (1983); Pritchard et al. (1983); Limpus, Fleay
& Baker (1984); Salm (1984); Limpus, G yuris & M iller
(1988); Zangerl, Hendrickson & Hendrickson (1988); Limpus et al. (in press).
Rem arks : Because o f its restricted geographical distribution, the flatback is the most vulnerable o f all sea turtles to
any change o f habitat or to o ver-exploitation (see section on “ Interest to Fisheries” for Kem p’s ridley), so it w as
necessary to develop a strict m onitoring schem e to continually trace the population level It is strongly recom m ended
to keep captures to a m inimum.
The flatback turtle nesting grounds and habitats in northern Australia need to be preserved from the degradation that
threatens the survival o f wildlife. “ Positive conservation m anagem ent by Australia and her neighbours is required to
ensure the survival o f these turtles, which by th e ir intrinsic biology, cannot adapt to long-term intensive harvests or to
rap id a lte ra tio n o f th e ir e n v iro n m e n t” (L im p u s, 1986).
National parks protecting turtle habitats have been established by the A ustralian governm ent as early as O ctober o f
1948; they include the southern coral cays in the G reat Barrier Reef, some o f them supporting turtle breeding
populations. An interesting exam ple is the National Park o f Peak Islands that had been protected for decades before
its fla tb ack rookery w a s discovered. In February 1982, the W ild Duck Island, a very im portant breeding area for
fla tb ack turtles, w as declared a National Park, and th is is the first legislation specifically designed for the conservation
o f the endemic N atato r depressus (Limpus, 1980).
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53
DERMO
2.3 FAMILY DERMOCHELYIDAE
Synonyms : Sphargidae;
Derm atochelydae,
D erm ochelidae,
D erm ochelydidae.
Derm ochelys Blainville, 1816
DERMO Dermo
Genus : Derm ochelys Blainville, 1816, Bull.Soc.Philom .Paris, p.119.
Type Species : Testudo coriacea Vandelii, 1761.
Synonym s : Sphargis Merrem, 1820; Coriudo Fleming, 1822; Siphargis Risso, 1822; Scytina W agler, 1828; Chelonia
Bory de St. Vincent, 1828; Derm ochelis LeSueur in Cuvier, 1829; D erm atochelys W agler, 1830; Chelyra Rafinesque,
1832; Testudo Ranzani, 1834; S cytena Gray, 1844; Sphragis Agassiz, 1846; Seytinia Naeve, 1940; D e rm a to c h e lis
Romer, 1950; Scytine Romer, 1956; Seytina Romer, 1956.
Diagnostic Features : See species.
Dermochelys coriacea (Vandelii, 1761)
figs 40, 41
DERMO Dermo 1
Testudo coriacea Vandelii, 1761, “ Epistola de Holoturio et Testudine coriacea ad Celeberrim um Carolum Linnaeaum,
Padua:2 (Maris Tyrrheni oram in agro Laurentiano).
Synonym s : Testudo coriacea: Linnaeus, 1766; Testudo coriaceous Pennant, 1769; Testudo arcuata Catesby, 1771;
Testudo lyra Lacépède, 1788; Testudo m arina Wilhelm, 1794; Testudo tuberculata Pennant in Schoepf, 1801 ; Chelone
coriacea: Brongniart, 1805; Chelonia coriacea: Schweigger, 1812; Chelonia lutaria Rafinesque, 1814; Derm ochelys
coriacea: Blainville, 1816; Sphargis m ercurialis Merrem, 1820; Coriudo coriacea: Flemming, 1822; Chelonia Lyra Bory
de St. Vincent, 1828; Scytina coriacea: W agler, 1828; Sphargis tuberculata: Gravenhorst, 1829; Derm ochelis a tla n tic a
LeSueur in Cuvier, 1829; Derm atochelys coriacea: W agler, 1830; Gadow, 1901; D e rm a to c h e ly s p o rc a ta W agler, 1830;
S phargis coriacea: Gray, 1831; C helyra coriacea: Rafinesque, 1832; Testudo coriacea m arina: Ranzani, 1834;
D e rm a to c h e ly s a tla n tic a : Fitzinger, 1836 (1835); Testudo (S p harg is) coriacea: Voigt, 1837; D erm och elyd is
tu b e rc u la ta : Alessandrini, 1838; C h elo nia (Derm ochelys) coriacea: van der Hoeven, 1855; Testudo midas F iartw ig,
1861; Sphargis coriacea var. Schlegelii Garman, 1884; Derm ochely coriacea: Boulenger, 1889; Sphargis
a n g u s ta
Philippi, 1889; D erm atochaelis coriacea: O live ira ,1896; Derm ochelys schlegelii: Stejneger, 1907; D erm atochelys
angusta: Quijada, 1916; Dermochelys coriacea coriacea: Gruvel, 1926; Derm ochelys coriacea schlegeli: M ertens and
M üller, 1934.
Subspecies : There are two subspecies (Atlantic: D.c. coriacea; Indo-Pacific: D.c. s c h le g e lii) proposed by several
authors, m ainly on the basis o f different geographical distribution patterns, but also d ifferences in coloration and
m orphological characters (head and body m easurem ents). It is said, for exam ple, that the num ber o f white blotches
covering the body may be sig n ifica n tly different in the 2
populations, although th is is a feature subjected to a
considerable degree o f variability; also, statistical differences have been observed in the mean carapace lengths o f
A tlantic and Indo-Pacific turtles. However, a detailed statistical and com parative analysis to validate the subspecific
status o f these populations has not yet been undertaken, and no com parative descriptions o f the two subspecies have
been p u b lis h e d .
FAO Names : En - Leatherback turtle; Fr - Tortue luth; Sp - Tortuga laúd.
54
D iagn ostic Features : T his is one o f the largest living reptiles,
surpassed in size only by some species o f crocodiles. Adults are easily
distinguished from all o ther species o f sea tu rtle s by th e ir spindleshaped huge bodies and th e ir leathery, unsealed keeled carapaces.
Furtherm ore, th e ir a n a to m ica l and
physio lo g ical
fe a ture s are
different from those o f other sea turtles, especially the presence o f
vascularized growth cartilages (chondro-osseus skeleton) and the
developm ent o f an endotherm y sim ilar to that o f marine m ammals.
The head o f the adult leatherback is small, round and scaleless, and
equals 17 to 22.3% o f the carapace length; beak feeble, but sharpedged, lacking crushing surfaces, w ell adapted to grab sluggish
pelagic food; upper ja w w ith two pointed cusps in front; low er jaw
with a single, pointed central hook that fits between the upper cusps,
w hen the m outh is closed, giving the appearance o f a W in front
view ; part o f m outh ca vity and th ro a t co ve re d w ith row s o f
posteriorly-directed spine-like horny papillae that prevent the prey
from m oving outward. Carapace reduced and form ed by a m osaic o f
sm all, polygonal osteoderm ic pieces, supported by a th ick m atrix o f
ca rtila g in o u s,
oily derm al tissue, w ith 7
dorsal and 5 ve n tra l
lo n g itu dina l
keels; dorsal keels (already present in hatchlings)
converging posteriorly in a blunt end, much above the tail. The scales
that cover the body in ju veniles are lost in subadults and adults, which
are covered
by a rubber-like, leathery skin. Shell bones (such as
neural, pleural, and peripheral bones) reduced in num ber or entirely
absent; the preneural bone is well attached to the 8th vertebra and
supports the neck elevator m uscles; plastral bones reduced to a ring.
Ribs ap p are n tly free, but em bedded in the carapace cartilage.
Flippers large and paddle-shaped; in adults, the fore flippers usually
equal or exceed h a lf the carapace length and th u s are relatively
longer than in other sea turtles; in hatchlings, they look enorm ous
and are clearly as long as the carapace; rear flippers connected by a
m em brane w ith the tail; claw s m ay be visible in hatchlings, but
d isappear insu b a du lts and adults. Colour:
adults show a certain
v a ria b ility in co lo u r pattern. Dorsal side esse n tially black, with
scattered w hite blotches that are usually arranged along the keels,
becom ing more num erous laterally and very dense beneath the body
and flippers, so that the ventral side is predom inantly w hitish. Pinkish
blotches on neck, shoulders and groin, becoming more intense when
the turtle is out o f the w ater, possibly by blood congestion in the skin
vessels. H atchlings and juve n ile s have more distinct w hite blotches
which are clearly arranged along the keels. The density o f the spots
and also th e ir size are highly va riab le am ong populations, but
apparently show a certain constancy within each population.
d o rs a l
rid g e s
dorsal view
w
- y
s h ap e d
b ea k
head
Fig. 41
M ales are distinguished from fem ales m ainly by th e ir longer tail; they also seem to have a more narrow and less deep
body. Apart from th e ir short tail, fem ales have a pink area on the crown o f th e ir head.
The eggs are covered by a soft w hite shell.
G eographical D istribution : A dult leatherbacks are adapted to colder w ater than other sea turtles, a capability that is
due to th e ir protective thick and oily derm is. As a result o f this, the leatherback is the m ost widely distributed o f all
sea turtles; there are num erous records from higher latitudes, very far from the tropical and subtropical nesting
grounds, w here the w ater tem peratures are between 10° and 20°C. The species thus easily reaches the North Sea,
Barents Sea, New Foundland and Labrador in the North Atlantic, and M ar del Plata, Argentina, and South Africa, in
the South A tlantic; it also occurs throughout the Indian Ocean, in the northern Pacific, to the G u lf o f Alaska and
south o f the Bering Sea, in the southw estern Pacific to Tasm ania and New Zealand, and in the southeastern Pacific to
Chiloé (Chile) (Fig. 42). In many o f the central and south Pacific islands this species is well known, and also nests on
some o f them . Very little is known about the distribution o f the hatchlings after they abandon the nests; ju veniles
and immatures are also difficult to observe.
55
20 °
40”
60°
80°
100 “
120 '
140 °
160°
180 °
Fig. 42
Habitat and Biology : The leatherback turtle is a highly pelagic species that approaches coastal w aters only during the
reproduction season; although sm all groups o f individuals have been reported m oving in coastal w aters in the middle
o f co n ce ntra tio n s o f je llyfish and tunicates, it seldom form s large a g g regations (flotilla s). W hen travelling, it
apparently w anders erratically in search o f food, but its m igration routes are only recently being traced on the basis o f
tag-recovery reports. Until recently, th is turtle w as considered to be strictly epipelagic, but new observations have
shown th a t it frequently d escends into deep w a te rs and that it is p h ysio lo g ically w ell adapted to deep-diving.
Feeding behaviour is known for adults and subadults, but not for hatchlings and juveniles. It is assum ed that this
species is carnivorous throughout its life cycle; the adults feed m ainly on jellyfish (Scyphom edusae), tunicates and
other epipelagic soft-bodied invertebrates, that are abundant in the epipelagic region, with highest concentrations in
upwelling areas and convergence currents.
Unlike m ost other sea tu rtle s w hich nest during spring and sum m er, the leatherback usually nests in autum n and
w inter w hen it arrives in large groups at the nesting sites and form s “arribazones” . The rookeries are characterized by
approaches o f deep water, absence o f fringing reefs, and high-sloped beaches that facilitate the landing o f these
corpulent anim als. The nest is usually constructed just across the high tide m ark and very often below it; in the latter
case, the entire clutch is lost w hen w ater invades the nest during spring tides.
The location o f the most im portant breeding grounds is as follows: Eastern Pacific Ocean: w estern coast o f Mexico,
with over 80 000 nests per ye a r (biggest nesting aggregations in M exiquillo, Tierra Colorada and Chacahua); scattered
nesting occurs from Mexico to Panama, with only several thousand nests per year, m ost o f them in Costa Rica (Playa
Naranjo) and Panama; w est coast o f Colom bia, Ecuador and Peru, but with no more than 500 nests per year. W estern
Atlantic Ocean: Caribbean: Trinidad and Tobago, 1 000 nests per year; W indward Islands, Leeward Islands and Virgin
Islands (Mona, Culebra, Vieques); east coast o f Puerto Rico; Dom inican Republic, 500 nests per year; Costa Rica,
between Tortuguero and Puerto Limon, with 5 000 nests per year; Panam a and Colom bia (G ulf o f Urabd); between
Surinam and French Guiana, 10 000 to 15 000 fem ales are reported every year; other breeding grounds along the
A tlantic coast o f South Am erica are located in Guyana, with 500 nests per year, and in Brazil (Espíritu Santo, Natal;
between Sergipe and Para). Eastern A tlan tic Ocean: only m inor and solitary nesting is recorded from M auritania,
Senegal, Liberia, Ghana, Togo, Zaire and Angola; no nesting has been reported from the M editerranean Sea in recent
tim es. Indo-Pacific region: in the W estern Indian Ocean, m inor nesting takes place in Tongaland, Natal (100 nests per
year) and M ozam bique; occasional nesting occurs in Tanzania, Zanzibar, Kenya, the Seychelles, Som alia, South
Yem en, Oman and on the Laccadive Islands; along the w estern coast o f India, nesting occurs around Goa and in
Kerala; for Sri Lanka, there w as an im portant breeding ground in the past; today, only a few dozen nestings per year
are recorded; m ajor breeding sites are known in M alaysia, Terengganu, but with an alarm ing decline in num ber o f
nesting fem ales (1950: 1 800 females; 1987: 100 fem ales); exact figures are available for Irian Jaya, with up to 5 000
nesting fem ales and about 20 000 nests per year; 50 nesting tu rtle s were counted in southeastern Java, and 200 in
W estern Sum atra, with approxim ately 1 000 nests each year; negligible breeding occurs in eastern and northeastern
56
Australia; no nesting activities are known from the Central Pacific islands, but from the South Pacific islands: Papua
New Guinea, the Solom on Islands, Vanuatu and Fiji; in China, nesting occurs in the provinces o f Kuangtung, Fukien,
Chekiang, Kiangsu, Shangtung and Liaoning.
The nesting season varies in extent, according to the latitude and geographical characteristics o f the coast: E a ste rn
P a c ific O ce a n: in M exico, nesting occurs in autum n and w inter, from O ctober to February or March o f the follow ing
year. W e s te rn A tla n tic O cean: in Colombia, French Guiana and Surinam, the season starts in March and ends in July, in
Guyana it goes from January
to March; in the Caribbean from spring to autum n (April to October), with a variation in
Panama (Isla Cañas), w here it lasts from March to June. E a ste rn A tla n tic O cean: for Senegal, nesting is
reported from
June to August; in South Africa it goes from O ctober to February. In d ia n O cean: nesting occurs from w inter to spring
as in the Seychelles (Novem ber to February) and the Andam an and Nicobar Islands (Decem ber to April), or from spring
to summ er, as in Sri Lanka (April to June) and India, Tamil Nadu (April to July); in W est M alaysia it goes from May to
September. W e s te rn P a c ific R egion: in China, the season runs from May to June, in Irian Jaya from May to September,
in Australia from Decem ber to February, and on the Solom on Islands, nesting occurs from N ovem ber to January.
Derm ochelys coriacea has a nesting cycle o f 2 or 3 years. Fem ales usually lay 4 or 5tim es per season (6 or 7 tim es on
Culebra Island, Puerto Rico),depositing on each occasion from 61 to 126 eggs. Usually, about h a lf o f the clutch
consists o f sm aller and yolkless eggs.
The size o f the egg clutch varies from place to place, from a m inimum o f 46 to a m aximum o f 160 eggs per clutch.
Som e exam ples are the follow ing: M exico - M ichoacan, mean valu e s o f eggs per clutch are: 59.1 (1982-83, n = 86), 58.4 (1983-84, n=355), 61.5
(1984-85, n = 1 203), 60.6 (1985-86, n =987), 62.4 (1986-87, n =42), 52.9 (1987-88, n =35); in the period 1988-89, a mean of 66.1 normal sized eggs
and a mean o f 43.4 yolkless eggs per clutch (n = 758) w ere recorded; Puerto Rico - from 60 to 93 normal eggs, with a mean o f 78.5 (n = 9), and 6 to
61 yo lkless eggs, w ith a mean o f 30.8 (n = 9); Costa Rica - A tlantic coast, from 46 to 128 norm al eggs, w ith a mean o f 81.6 (n = 47), and 9 to 77
yolkless eggs, with a mean o f 29.8 (n = 46); P acific coast, from 53 to 79 norm al eggs per clutch, w ith a m ean o f 65.5 (n= 6), and 15 to 66 yolkless
eggs, with a mean o f 31.5 (n = 6); Trinidad - the clutch size ranges from 65 to 130 eggs (no detailed data available); Surinam - from 52 to 128 eggs,
with a mean o f 85.0 (n = 385); yolkless eggs from 1 to 60, with a mean o f 23.0 (n = 195); French Guiana - in one count, eggs per clutch ranged from
50 to 148 (mean 84.3), in another 51 to 112 (mean 88.1, n = 19); yolkless eggs ranged from 9 to 57, with a m ean o f 29.1 (n = 19); South A frica - in
Natal the mean values are 106 norm al and 30 yolkless eggs per clutch; Tongaland from 58 to 160 eggs, with a mean o f 103.9 (n = 252), and 3 to 57
yolkless eggs, w ith a mean o f 30.0; A ndam an and Nicobar Islands - m ean valu e s o f 79 norm al eggs and 23 yolkless eggs per clutch; Australia
Q ueensland from 64 to 100 eggs, w ith a mean o f 82.8 (n = 14) and 18 to 79 yolkless eggs per clutch, w ith a m ean o f 46.5 (n = 13); M alaysia Terengganu from 58 to 160 eggs, with a m ean o f 82.3 eggs (n = 627); Sri Lanka - num ber o f eggs per clutch range from 90 to 130, no other data
available; China - 90 to 150 eggs per clutch, no o th e r data available.
Together with the flatback o f Australia, this species has the largest eggs and hatchlings am ong sea turtles. Data on
egg diam eter (range: 51.0 to 54.4 mm) and egg w eight (range: 70.0 to 103.6 g) are relatively scarce. Variation in
d iam eter is more m arked in yolkless eggs.
Som e exam ples are the follow ing: M exico - M exiquillo: egg size from 45.6 to 59.2 mm, w ith a m ean o f 51.2 (n =420); egg w eight from 54.5 to 93.4
g, with a mean o f 76.7 g (n = 420); C osta Rica - A tla n tic coast: egg size from 49.2 to 54.9 mm (20 eggs o f 26 different clutches m easured); egg
w eight from 72.6 to 103.6 g (20 eggs o f 26 different clutches m easured); size o f yolkless eggs from 1 to 47 mm (n = 19 clutches); yolkless eggs made
up 3 to 23% o f the total w eight o f a clutch; clutch w eights range from 4.02 to 13.39 kg, w ith a m ean o f 7.4 kg; Pacific coast: mean size o f eggs 51.0
mm (n = 6 clutches), with yolkless eggs ranging from 15 to 45 mm ; C olom bia - egg size from 53.5 to 59 mm, with a m ean o f 56.1 mm (n =9 eggs);
egg w e ig h t from 80 to 98.9 g, w ith a mean o f 89.4 g (n =9 eggs); Puerto Rico - mean size o f eggs 54.5 mm (n = 90 eggs); Trinidad - egg size range
from 52 to 65 mm; Surinam - egg size from 50 to 57 mm, w ith a mean o f 53.0 mm; French Guiana - m ean egg d iam eter 65 mm; South A frica Tongaland: egg size from 50 to 56 mm, with a mean of 53.1 mm (n = 165); Andam an and N icobar Islands - egg size from 48.8 to 51 mm; India - egg
size from 50 to 55 mm; egg w eight from 70 to 80 g; Sri Lanka - egg size from 50 to 54 mm; egg w eight from 61 to 85 g; Australia - Q ueensland: egg
size from 51.1 to 56.2 mm, with a mean o f 53.2 mm (n = 120 eggs; 12 clutches); egg w eight from 74 to 90.8 g, with a mean o f 81.9 g (n = 70 eggs; 7
clutche s).
The incubation period varies from a m inim um
o f 50 to a m aximum o f 78 days, and is correlated with tem perature
humidity. In dry and warm weather, the incubation period is shorter, with a lower survival rate.
and
M exico-M exiquillo, 58 to 78 days (1980-81), with a mean o f 65.2 days (n = 12 clutches, transfered nests); C osta R ica - A tlantic coast, 58 to 66 days
fo r transfered nests, with a mean o f 61.5 days; in Saint Croix, the incubation period varied from 60.3 to 63.9 days fo r undisturbed nests; P u e rto R ic o
- 55 to 59 days, with a mean o f 57.6 days (n = 9 clutches, transfered nests); S u rin a m - 60 to 70 days, with a mean o f 64.1 days (n = 56 clutches); French
G uiana -1 9 8 1 : 59 to 74 days; 1982: 69 to 78 days: 1983: 67 to 76 days; 1984: 62 to 72 days; S o u th A fric a - Tongaland, 56 to 72 days; Sri Lanka - 58 to
65 days, with a mean o f 60 days; M alaysia - 53 to 60 days fo r tra n sfe re d nests; A u s tra lia - 60 to 61 days.
Size and w eight o f hatchlings vary between
nesting sites, seasons and years. The straight carapace
ranges from 51 to 68 mm, the mean weight from 37.6 to 48.6 g.
length (SCL)
Data on size (SCL) and w eight o f hatchlings are available fo r the follow ing places: M e x ic o - M exiquillo, from 51.0 to 60.0 mm , w ith a m ean o f 56.1
mm and a mean w eight o f 39.4 g (n = 8 clutches, 78 hatchlings); Guerrero, from 57.7 to 65.3 mm , w ith a m ean o f 62.1 mm (n = 13); C osta R ica A tlantic coast, from 54 to 63 mm, w ith a mean o f 59.8 mm (n =6 clutches, 120 hatchlings) and a m ean w eight o f 44.6 g (range: 40 to 50 g, n =6
clutches, 120 hatchlings); Saint C row (Sandy Point), mean size 61 5 mm and body w eight from 42.5 to 45.8 g; C o lo m b ia - from 58.6 to 62 mm, with a
mean o f 60.4 mm and a mean w eight o f 48.6 g (range 43.2 to 51.9 g, n = 7); T rin id a d - 66 and 68 mm (n = 2 hatchlings); S u rin a m - from 57 to 61.3
mm, w ith a m ean o f 59.2 mm (n =27 hatchlm gs), F re n ch G u ian a - one hatchling w ith 67 mm SCL and a w eight o f 46 g; S o u th A fric a - Tongaland,
from 54.8 to 63.4 mm , w ith a mean o f 58.7 mm (n = 131 turtles) and a m ean w eight o f 37.3 g (range: 27.5 to 41 g, n =47 turtles), A u s tra lia Q ueensland, from 51.4 to 65.2 mm, with a m ean o f 58.8 mm (n =4 clutches, 29 turtles) and a m ean w eight o f 46.9 g (range: 38.3 to 54.2 g, n =4
clutche s, 39 tu rtle s)
57
There is only one published observation on courtship and m ating. A ccording to th is report, courtship lasted for 20
m inutes. W hen finally accepted by the fem ale, the male m ounted her carapace, em braced her with his flippers, and
m a tin g began.
Incubation tim e ranges from 50 to 70 or more days, in accordance with the w eather. The optim al incubation
tem perature for eggs o f this species is around 29°C. There is evidence that sex determ ination is m ale-biased in cool
tem peratures and vice versa. The “ pivotal te m perature” , defined as the tem perature w here a 1: 1 sex ratio occurs,
ranges betw een 29.0°C and 29.95°C. Incubation experim ents on 72 hatchlings and 11 embryos, carried out by the J.
M onod Institute, Paris, indicate that an incubation below 28.75°C results in phenotypic m ales, w hile incubation
te m p e ra tu re s above 29.75°C produce fem ales.
Em ergence o f the hatchlings occurs m ostly at night; after having reached the surface o f the nest, they rem ain for
some tim e h a lf exposed, before they run rapidly to the su rf zone. Predation occurs throughout the life-cycle, but is
highest during incubation and em ergence. P redators are the same as for other sea turtles, but the hatchlings o f
D erm och elys coriacea are too large for sm aller predators. The eggs and em bryos are consum ed by ghost crabs
(O cypode sp.), throughout the nesting range, in some cases, clutches are destroyed by ants or fungal and bacterial
infections. Other predators are vultures (C oragyps sp.), dom estic and feral dogs, jackals, pigs and wild boars. M onitor
lizards ( Varanus sp.) are im portant nest predators in South Africa (Tongaland), Australia (Queensland) and
Sri
Lanka.
After em ergence and while they are running to the su rf zone, hatchlings are attacked by birds (vultures, kites, crows,
grackles and owls) and m am m als (genet cats, m ongoose, skunks, racoons, coatis, opossum s and jaguars). In the water,
hatchlingsare captured by sea birds (frigates, gulls, etc.), carnivor fishes and squids.
Juveniles and adults are attacked by sharks. Bones o f the leatherback turtle were recovered from the stom achs of
killer w hales (Orcinus orca). Plastic w astes are another cause o f m ortality, since the tu rtle s confuse these m aterials
w ith je llyfish and sw allow them , thus clogging th e ir throat, esophagus and intestines. In some areas, e.g. in French
Guiana, high m ortality o f fem ales is caused by roots and logs o f dead m angroves that choke the tu rtle s when they
ascend the beach to nest.
Parasites, as trem atodes (A strorchis renicapite) and amoebae (Entam oeba sp.), are found in the intestines. Com monly
these tu rtle s are covered by e pibiontic organism s, e.g. barnacles (C helonibia sp., C onchoderm a sp.. Lepas sp.,
Stomatolepas sp.. Platylepas sp., Balanus sp.) and parasitic isopods (e.g.
Excollarana sp.). so far, no papillom atosis has
been reported.
Derm ochelys coriacea feeds m ainly on pelagic invertebrates, such as jellyfish e s and tunicates, pelagic crustaceans
(,Libina sp.. Hyperia sp.), juvenile fishes (Trachurus sp.. Urophycis sp.) and marine plants are ingested accidentally.
The feeding behaviour o f hatchlings and ju veniles is unknown, but is believed to be sim ilar to that o f adults. They are
assum ed to be pelagic, m igrating along the borders o f warm currents and eddies, in search o f food.
S ize : This species is not only the largest living sea turtle, but also one o f the largest extant reptiles. The largest
specim en ever recorded, w as a male o f 256.5 cm carapace length (CCL) and a body weight o f 916 kg, found dead on
Harlech Beach in G w yneed, W ales, in S eptem ber 1988. Although the exact age at first m aturity is unknown, this
species is believed to reach sexual m aturity after 3 or 4 years, at a size o f 1.25 m o f straight carapace length. Data
obtained from anim als in captivity indicate that D erm ochelys coriacea grow s faster than any other marine turtle.
If not stated otherwise, the following data on size (SCL and CCL) and body weight refer to nesting females: Mexico: Mexiquillo, 1983-84: 129 to 163
cm SCL with a mean of 145.8 cm (n = 85); 1987-88: 124 to 162 cm SCL, with a mean of 144.4 cm (n = 52); 1988-89: 126.5 to 187.5 cm SCL, with a
mean of 144.6 cm (n = 395); Costa Rica: Atlantic coast, Jalova Beach, 134.6 to 172.7 cm SCL, with a mean of 152.1 cm (n = 76); Pacific coast, 128 to
151 cm SCL with a mean of 141.0 cm (n = 18); In Saint Croix, Sandy Point, the straight carapace length of nesting females ranges from 137 to 176 cm
and the body weight from 258 to 506 kg; Puerto Rico: 153 to 160 cm SCL (n = 2); Trinidad: 135 to 185 cm CCL, with a mean of 156.5 cm (n = 20);
Colombia: 140 to 170 cm (CCL), with a mean of 155.6 cm (n = 7); Guyana: three females of 137.5, 152.5 and 162.5 cm SCL; Surinam: 143.3 to 164.5
cm SCL, with a mean of 153.8 cm (n= 16); the smallest female weighted 302 kg; French Guiana: 135 to 189 cm CCL, with a mean of 158.5 cm
(n = 834); Senegal: one female measured 183 cm (SCL ?), the weight of another was calculated between 200 and 250 kg; for India: southeastern
coast, only three length measurements (SCL ?) of non- nesting females are recorded, 213 cm (body weight 272 kg), 195 cm and 190 cm; Sri Lanka:
147.5 to 165 cm CCL, with a mean of 155.9 cm (n =4); the body weight of the smallest specimen was 301 kg, that of the largest 448 kg; Australia:
Queensland, 150 5 to 174.5 cm CCL, w ith a mean of 162.4 cm (n = 9).
Data on size and weight o f males and non-nesting females are rare.
Some examples are the following: Canada: Labrador Peninsula, one male with a carapace length of 165 cm and about 500 kg of body weight, and
one female of 147 cm carapace length and 379 kg of body weight, both captured In September 1973; Nova Scotia, 106 to 177 cm carapace length
(SCL ?), with a mean of 149 cm (n =9, 1889 to 1966), USA: Massachusetts, Cape Cod Bay, 124.5 to 170 cm CCL, with a mean of 144.8 cm (n =25);
New Jersey, one stranded female that measured 145 cm (SCL); Bardados Island; Cattlewash Beach, one juvenile of 19 cm SCL; Chile: two specimens
with 137 and 148 cm CCL; the holotype o f Sphargis angusta Philippi, 1899, deposited in the Natural History M useum of Valparaiso, has a carapace
length of 186 cm; Madeira: one female with a carapace length (CCL) of 166 cm; Europe Brongersma (1972) lists 188 records of the leatherback
turtle (period: 1901-1970). but only for 11 specimens, all of them caught between June and September, Information on size and weight is available,
the carapace length ranged from 135 to 162 cm, and body weight from 494 to 1 069 kg, new data are available for Greece, where 11 subadults and
adults were caught, their carapace length ranging from 123 to 180 cm; Mauritania: one female with 150 cm and two males with 143 and 155 cm of
carapace length; a no the r m ale w eighed 600 kg; Egypt, Red Sea: tw o m ales w ith 168 and 143 cm o f carapace length (C CL); South A frica:
58
nine records between 1969 and 1973; a juve n ile o f 76 cm SCL (body w eight 27.3 kg), one m ale o f 162 cm C CL (body w eight 320 kg), and seven
fem ales with a carapace length (CCL) from 119 to 170 cm (body w e ig h t from 150 to 646 kg).
Interest to Fisheries : A dults are caught incidentally by set or drift nets used for pelagic fishing and by longlines used
for tuna, sailfish, swordfish, and sharks. G enerally speaking, there are no com m ercial fish e rie s for this species,
although in some places it is used as bait in longline shark fisheries. In many countries, the leatherback population
has been threatened by egg-harvesting, i.e. M alaysia and Sarawak, Surinam, the Guianas, Mexico (west coast) and
Costa Rica; also in several o f the Caribbean islands, w here the leatherback w as abundant tw o decades ago. In
Terrengganu, M alaysia, the num ber o f nesting fem ales decreased from 1 800 in the fiftie s to not more than 100 in
1988.
The lack o f an organized fishery for the adults o f this species is partly due to the fact that they have no valuable scutes
as the hawksbill, nor can they be used as a source o f leather as the-olive ridley; however, they yield many litres o f oil
which w as used in the past for caulking w ooden boats and for oil lamps. The FAO Yearbook o f Fishery Statistics does
not report leatherback catches, but it is possible that catches are included under the item “M arine tu rtle s n .e .i.”
(u n id e n tifie d s p e cie s).
Rem arks : It is now considered an “endangered sp e cie s” thro u g h o u t its d istributional range. It is included in
Appendix I o f the CITES and in the Red Data Book o f the IUCN. No official statistics are available on catches o f this
species. In the m ajority o f countries, this species is fully protected, but in m any o f them , legal enforcem ent o f these
protective m easures is difficult. Hence, indiscrim inate poaching o f eggs on beaches and capture o f adults in the sea or
in nesting areas is still widespread. Rearing o f this turtle in captivity w a s attem pted on several occasions, w ithout
success, possibly because o f the anim al dam aging itse lf by swim m ing m ainly in one direction and hitting its snout
against the wall o f the container. However, several individuals have been reared for up to four years, before they
died or were released.
Local Nam es : ALDABRA: Carem bol; AND AM AN ISLANDS: Sher-cacchua; BANGLADESH: Sam udrik kasim: BRASIL:
C anastra, C arepa becerra, T arta ru g a de courot, Tartaruga grande encourada; CAR IB BE AN REGION: Kawana;
CAYM AN ISLANDS: Trunk; CO LO M BIA: Bufeadora, Canal, Gaula; CHILE, ECUADOR, PERU: Tartaruga laud, Tortuga
siete filos; CHINA: Leng-Pi-Gui; COSTA RICA, EL SALVADOR: Baula, Laúd; CUBA: Tinglado; FRANCE: Tortue luth;
FRENCH GUIANA: Kawa-na; G ERM ANY: Lederschildkrote; GOLD COAST: Bosange, (Swahili): Noa; G UATEM ALA:
Baule, Licotea; GUYANA: M ata-m ata; INDIA (Tam il-N adu): Eluvarai-am ai, D honi-am ai, Thoni-am ai; INDO CHIN A
(Vietnam ): Ba-Tam ; INDO NESIA: Penyu belim bing, Labi-labi; (Irian Jaya): Kopem; ITALY: Sfargide, Tartaruga de luth,
T artaruga liuto; JAPAN: Osa game; M ALAYSIA: Penyu belim bing; M EXICO: Tortuga laúd, Tortuga de cuero, Chalupa
siete filos, Tinglada, M achincuepo, G alapago; M IC R O N ESIA (Truk District): M irang, W ongera; (Yap D istrict-Central
Carolines): W onera; NEW GUINEA: Tonesu, Foakona, Goli, Tinuk, Veu, Epapo, Mabua, Latuk, Pwiri, Kuaurai, Peleleu,
W edara, M anibu, Bolu; NICARAGUA (Pacific): Tora; PANAMA: Tortuga de canal; PHILIPPINES: Pawican; PORTUGAL:
Tartaruga; PUERTO RICO: Tinglar; RED SEA, EG YPT (Arabic): Na’ama; SENEG AL: Tortue luth, Tortue de cuir;
SE YC H E LLE S: Torti karam bol; SPAIN: Tortuga laúd; SRI LANKA: Dhara kasloave, Dhoni amai; SOUTH AFRICA: Irundu,
Inhasa, Ronto, Valozoro; (Afrikaans): Leerrugseeskilpad; (Dutch): Lederschilpad; SUR IN AM : A itkanti, Siksikanti:
THAILAND: Tao-M a-Fueung; UK, USA: Leathery, Luth, Leatherback, Leather-trunk turtle; VENEZUELA: Tortuga laud,
T re s quilla s, C halupa.
L ite ra tu re : Deraniyagala (1939); Yáñez (1951); Carr (1952); Leary (1957); Loveridge & W illiam s (1957); Hendrickson
(1961, 1962); W erm uth & M ertens (1961); Bleakney (1965); M cCann (1966); Balasingam (1967); Capocaccia (1967);
Huges & M entis (1967); Hughes, Bass & M entis (1967); Brongersm a (1968, 1969, 1972); M oiseev (1969); C adw ell
&
Erdman (1969); Pritchard (1969, 1971, 1976, 1982a,b); M árquez (1970); Bacon (1971); Ferreira de M enezes (1972);
Kaufman (1973); Rebel (1974); Schulz (1975, 1984 ms); Frazier (1975, 1984, 1987); Cornelius (1976); M cConnaughey
(1978); T hrelfall (1978); Limpus, Neville & McLachlan (1979); Sm ith & Smith (1980); Rhodin et al. (1980); M eylan
(1981); Bacon (1981); Sternberg (1981); Lim pus (1981); Spring (1981); Kuan Tow (1981, 1988); Balazs (1981, 1982);
Ram boux (1982); G room bridge (1982); Rhodin & Smith (1982); Rhodin & S choelkopf (1982); Frazier & Salas (1982,
1984); Benabib (1983); M aigret (1983); Rajagopalan (1983); Eisem berg & Frazier (1983); Fritts, Hoffman &
M cG ehee
(1983); Limpus et al. (1984); Pritchard & Trebbau (1984); Baskar (in litt., 1985); Meylan & Ruiz (1985); W hitm ore &
Dutton (1985); Fretey & Lebean (1985); Frazier, Meneghel
& Achaval (1985); Carr & Carr (1986); Dupuy (1986); Eckert
et al. (1986); FAO (1986); M argaritoulis (1986); M atos (1986); Fretey (1986, 1987); Horrocks (1987); Eckert (1987, pers
com.); Hirt & Ogren (1987); Fretey S G irondot (1987); Chan (1988); Lim pus et al. (1988); Lutz (1988); Prescott (1988);
Z angerl (1988); A lvarado & Figueroa (1988); Eckert & Eckert, (1988); Stinson (1989); Diaz et al. (1989); Dutton
(p e rs .c o m .).
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3.
LIST OF SPEC IES
BY M AJOR
FISHING
AREAS
GEOGRAPHICAL DISTRIBUTION
SPECIES
MAJOR MARINE FISHING AREAS FOR STATISTICAL PURPOSES
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87
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Caretta caretta
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C helonia agassizii
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C helonia mydas
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Eretm ochelys im bricata
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Lepidochelys k e m p ii
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Lepidochelys olivacea
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N a ta to r depressus
49
Derm ochelys coriacea
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M AJO R
M ARINE
FISH IN G
AREA S
FOR
S TA TIS TIC A L
PU R PO SES
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61
4.
A chaval, F.,
BIBLIOGRAPHY
1965. Hallazgo de C h elo nia m yd as (Linné) (Tortuga
108:27-28
Acuna, M .R. A.,
Verde) en el
U ru g u a y.
Rev. O ficial del Club
1988. Influencia del cautiverio, peso y tam año en la m igración de Ios neonatos de
o livacea E schscholtz (T estudines: C helonidae). R e v.B io l.T ro p ., 36(1 ):9 7 -1 06
A n c a p .,
Lepidochelys
Aguayo, C .G., 1953. La tortuga bastarda (Lepidochelys olivacea k e m p ii) en Cuba. M e m .S o c.C u b a n a H ist.N a t., 21 (2 ):2 1 1 9, ta b l.5
A lfaro, L.M.,
L.M. Blain & D.L. Munoz, 1987. “ Evaluación de la población de to rtu g a s m arinas en el area de Buritaca a
Don Diego (M agdalena) durante Io s m eses de Mayo a Julio de 1987” . Universidad de C o lo m b ia F acultad de Biologia M arina. Inform e de Trabajo (ms): 27 p.
A lvarado, J., & A. Figueroa, 1986. The ecological recovery o f the sea tu rtle s o f M ichoacan, Mexico. Special attention: The
black turtle (Chelonia agassizii). Final Report to WW F US and US Fish and W ildlife Service, 1986, 69 p.
A lv a ra d o ,
J .,A .
F igueroa & H. G allardo ,
1985. Ecologia y coservacion de
M exico. C uadernos de Investigación, UM SNH, M exico, 4:44 p.
las to rtu g a s m arinas de
M ichoacán, de
Argano, R. & F. B aldari, 1983. Status o f W estern M editerranean Sea Turtles. Rapp. Comm. Int. Mer. M ed it., 2 8 (5 ):2 3 3 -5
Babcock, H.L., 1919. Turtles o f the Northeastern United States. Dover Pubs., Inc., NY, 105 p.
Bacon, P .R., 1971. Sea turtles in Trinidad and Tobago. Paper 13. Proc. 2nd W orking M eeting o f M arine Turtle Specialists
Group. SS/IUCN. 8-10 M arch,1971. Morges, Switzerland. IUCN Pub. New. S er., S.P.31:79-84
Balasingam,
E.,
1967. The ecology and conservation o f the leathery turtle, D erm ochelys coriacea (Linn.), in Malaya.
Proc. 11th P acific S c .C o n g re s s ,T o k y o :3 7 -4 3
B alazs, G.H., 1 9 8 0 .Synopsis o f Biological data on the green turtle in the Hawaiian Islands. NOAA Tech. M em orandum ,
NMFS., 141 p.
----------------------------- , 1984. Im pact o f ocean de b ris on m arine turtles: entanglem ent and ingestion. In R.S. Shom ura &
H.O. Yoshida (eds): Proc. o f the W orkshop on the Fate and Im pact o f Marine Debris. 27-29 Nov. 1984,
H aw aii: 1-38
----------------------------- , 1981. Status o f sea turtles in the Central Pacific Ocean. ]n K. Björndal (ed.): Biology and conservation
o f sea tu rtle s. Proc. W orld C onf.S ea T urtle C o n s e rv ..W a s h .,D .C .,26-30 N o v.1979 , 243-52
B astian, A .F., 1983.
Nesting site and hatching o f the
M a r.Fish.Infor.S erv. T. and E. Ser, 50:33-4
Battstrom , B .H.,
1955. Notes on the herp e to lo g y
N aturalist, 54(1 ):2 1 9-29
of
haw ksbill
the
turtle
R evillagigedo
along
Island,
T iru n e lve li
M exico.
Coast
The
o f Tam il
A m erican
_________________ _ 1982.
Breeding o f the green sea turtle, Chelonia mydas on the Isia s R e v illa g ig e d o , M exico.
Review 13(3):71
Baur,
G .,
Benabib,
1890.
The genera o f the C helonidae. Am er. N a tu r., 24:486-7
N.M.,
1983. A lg u n o s a sp e cto s de la biologia de
Facultad de Ciencias, (T e sis Prof.), 83 p.
Nadu.
M idland
Herp.
Derm ochelys coriacea en el Pacifico m exicano. U N A M -
Berry, F.H. e ta /., 1983. The National Report for the country o f United S tates o f A m erica. W estern A tla n tic Turtle
Sym posium , San Jose, C .R .,17-22 July, 1983 (eds: P. Bacon, F. Berry, K. Björndal, H. Hirt, L. Ogren and M.
W eber), 3 :423-88
Bhaskar, 5., 1979. Sea tu rtle s survey in the A ndam an and Nicobar. H am adryad. 4 (3 ):26
Björndal, K. A. & A .B . M eylan, 1983. Sea tu rtle s nesting at M elbourne Beach, Florida, 1. Size, growth and reproductive
biology.
B io l.C o n se rv., 26(1983):65-77
62
Björndal, K. A., e t al., 1985. R eproductive biology o f the hawksbill Eretm ochelys im bricata at Tortuguero, Costa Rica,
w ith notes on the ecology o f the sp ecies in the C aribbean. B io l.C o n se rv., 3 4 :53-368
B leakney, S.,
1965.
R eports o f m arine tu rtle s from New England and Eastern Canada. Can. Field N a t., 792: 120-8
Bonnet.B .. J.Y. le Gall & G. Lebrun, 1980. T ortues M arines de la Réunion et des Iles Eparses. Conseil Régional de la
Réunion, Université de la Réunion 25 p.
Boulenger, G.A., 1889. Catalogue o f the chelonians, rhynchocephalians and crocodiles in the British M useum (Natural
History). Brit.M us. (Nat.Hist), London, 311 p.
B oulon (Jr.), R .,K Ecker & S. E cker, 1988. D e rm o c h e ly s c o ria c e a (le a th e rb a ck sea tu rtle ). M ig ra tio n . H e rp .R e v ie w ,
19(4):88
Bourret, R. & F. le Polain, 1941. Les to rtu e s de l’Indochine. A vec une note su r la pêche et l’élevage des tortues de m er
par F. Le Poulain. Notes Inst.O céanogr.Indochine S tn.M arit.C auda, N h a tra n g , (38):235 p.
Brongersm a, L.D., 1968. Notes upon some tu rtle s from the Canary Islands and from
Akad. W e te n sch ., (C)71(2): 128-36
_________________ 5 1969.
M iscellaneous
_________________ ; 1972.
E uropean
notes on turtles.
A tla n tic tu rtle s.
IIA-B.
M adeira.
Proc. Koninkl. Nederl.
Proc.K oninkl.N ederl.A kad.W etensch., ( C )72(1 ):76-102
Z oo l. V e rh a nd . L e id e n , 121 :3 1 8 p.
_________________ 5 1981. M arine turtles o f the Eastern A tlantic Ocean. In K. Björndal (ed.): Biology and conservation o f
sea turtles. Proc. W orld Conf. Sea Turtle Conserv., W ash., D.C., 26-30 Nov. 1 979:407-16
Brooke, M. de L. & M. C. G arnet, 1983. Survival and reproductive perform ance o f haw ksbill Eretm ochelys im bricata
on Cousin island, Seychelles. B io l.C o n se rv., 25: 161-70
Bruno,
S.,
1973. T artarughe m arine nel M editerráneo. In: III
Bari, 2-6 M aggio 1973. 11:11-2
S im p o sio
N azionale sulla C o n se rva zio n e
della
Natura,
Bustard, R., 1972. Sea turtles, th e ir natural history and conservation. T aplinger Publ. Co., New York, 220 p., 16 figs,
24 pis
B u s ta rd ,
R .H . & C. Lim pus,
25(1 ):29-34
1969.
Bustard,
R.H. & C. Lim pus, 1971.
C aldw ell,
D.
K.,
O bservations on the flatback turtle
Chelonia d epressa Garm an.
H erpetologica,
Loggerhead turtle m ovem ents. Brit. J. H e rpe to l., 4(9):228-30
1959. The A tlantic loggerhead sea turtle, Caretta caretta caretta (L.), in Am erica. III. The loggerhead
tu rtle s o f Cape Rom ain, South C arolina. Bull. Florida State Mus. Biol. S e i., 4 (1 0 ):3 1 9-48
_________________ 5 1962. G rowth m easurem ents o f young captive A tlantic sea tu rtle s in tem perate w aters. Los A ngeles
C o.M us., C o n trib .S ci., 50:1-8
----------------------------- , 1962a. Sea turtle in Baja California w aters (with special reference to those o f the G u lf o f C alifornia),
and the description o f a new subspecies o f northeastern Pacific green turtle. Los A ngeles C o.M us.,
C o n trib .S c i., 61: 1-31
----------------------------- , 1962b. Carapace lenght - body w eight relationship and size and sex ratio o f the northeastern Pacific
green sea trutle Chelonia mydas carrinegra. Los A n g e le s Co.Mus., C ontrib.S ci., 6 2 :1 -1 0
_________________ ; 1963. The sea turtle fishery o f Baja C alifornia, Mexico. Calif. Fish and G a m e , 49(3): 140-51
----------------------------- ,1 9 6 9 . Baby loggerhead turtles associated with Sargassum weed. Art. J Florida A ca d .S ci.. 31 (4 ):2 7 1 -2
----------------------------- ,1 9 6 9 a . Hatchling green turtles Chelonia m ydas at sea in the northeastern Pacific Ocean. Bull. S. Calif.
Acad. Sei., 68(2): 113-4
C a ld w e ll,
D.K. &
A . C a rr, 1957. Status o f the sea turtle fishery in Florida. Transct. 22th North Am .W ildlife
pp. 457-63
C onference,
63
Caldw ell, D.K. & D.S. Erdm an, 1969. Pacific Ridley sea turtle Lepidochelys olivacea in Puerto Rico. Bull.So. Calif. Acad.
S e i., 6 8 (2 ): 112
C aldw ell,
D.K., A.
C arr & T.R . H ellier, Jr., 1955. Natural history notes on
caretta caretta. Q u a rt.J.A ca d .F lo rid a S e i., 18(4):292-302
Capocaccia, L., 1966. Variabilité delta popolazione
Naturale di G enova, 76:22 p.
-----------------------------;
M editerranea di
1967. La D erm och elys coriacea (L.)
Ligure di Scienze e Lettere, 24: 12 p.
Cari, G .C., 1955. The green turtle in British Colum bia.
the A tla n tic
loggerhead
Caretta caretta (L.). An.
nel M editerráneo (Reptilia,
turtle
Caretta
Museo
Civico di Storia
T estudinata). Atti
d e ll’ Academ ia
Rep.Prov.M us.N at.H ist.Anthr., Victoria, B .C ., 1 9 5 4 (8 ):7 7 -8
Carr, A., 1952. H andbook o f turtles o f the United States, Canada and Baja California. Ithaca, C om stock Pub. Assoc.,
C ornell Univ. Press, 542 p.
-----------------------------,
1962.
Guidepost o f animal navigation. BSCS Pamphlet no. 1:36 p.
_________________ 5
1975. The Ascención Island Green Turtle colony. C opeia, 1975(3):547-55
-----------------------------,
1986. New perspectives on the pelagic stage o f sea turtle
SEFC, 190:36 p.
-----------------------------,
1986a.
Rips, fands and little loggerhead.
-----------------------------, 1987. New
1(2):103-21
perspectives
on
the
p elagic
developm ent.
NOAA Tech.M em .N M FS -
B io .S e i., 36(2):92-100
stage
o f sea
tu rtle
developm ent.
C onservation
B io lo g y,
Carr, A. & M.H. Carr, 1972. Site fixity in the Caribbean green turtle. Ecology, 53(3):425-9
Carr, A.
& H.
H irt, 1962. The ecology and m ig ra tio n s o f sea tu rtle s.
turtle colonies. Am er. Mus. N ovitates. 2091:42 p.
C arr,
& S.
S tancyk, 1975. O b se rva tio n s
C o n se rv.,
8:161-172
A.
on
the
e cology
and
5.
su rvival
C om parative
o u tlo o k
fe a ture s o f isolated
o f the
haw ksbill
green
tu rtle .
Biol.
Carr, A., H. H irt & L. Ogren, 1966. The ecology and m igrations o f sea turtles. 6 . The hawksbill turtle in the Caribbean
Sea. Amer. Mus. Novitates, 2248: 1-29
Carr, A ., L. O gren & C. Me Vea, 1980. A pparent hibernation by the A tlantic loggerhead turtle Caretta caretta o ff Cape
Canaveral, Florida. Biol. C onserv., 19(1980-81 ):7 -1 4
Carr, T. & N.Carr,
1986.
Derm ochelys coriacea (Leatherback sea turtle): Copulation.
Herpetological R ev., 17(1):24-5
Carranza, J., 1956. Marine fisheries o f the Yucatan Peninsula, Mexico. Proc. Gulf, and Carib. Fish. In st., 9: 145-50
Casas, A.
&
C han, E.H.,
S.
1988.
G om ez-A g u irre, 1980. C ontribución al conocim iento de Ios hábitos alim enticios de Lepidochelys
olivacea y Chelonia m ydas a g a s s izi (R eptilia, C heloniidae) en el Pacifico m exicano. Bolm. Inst.
O ceanogr., S. P a u lo , 29 (2):87-9
An update
N e w sle tte r,
on the
42:4
le a th erb a ck
tu rtle s
of
Rantau
Abang,
T erengganu,
M alaysia.
M a r .T u r tle
C hu-C hien, H., 1981. Distribution o f sea tu rtle s in China Seas. In K. Björndal (ed.): Biology and conservation o f sea
tu rtle s. Proc. W orld Conf. Sea T urtle s C onserv., W ash., D.C. 26-30 Nov. 1979
Cliffton, K. & D. Cornejo, 1983. The recovery o f Chelonia m ydas agassizii, the East Pacific green turtle o f Mexico.
Report to US Fish & W ildlife Service, 76 p.
Final
Cornelius, S .E., 1976. M arine turtle nesting activity at Playa Naranjo, Costa Rica. Brenesia, 8:1-27
D eraniyagald,
P .E .P., 1939. The tetrapod reptiles o f Ceylon. Vol.
C olom bo M us.N at.H ist.S eries, 412 p.
I Testudinates and crocodilians.
Ceylon Jour.
Csi.
64
De Silva,
G.S.,
1969.
Turtle
Conservation
in
Sabah.
Sabah
Soc.Jour.,
5(1 ):6-26
_________________ 5 1981. The status o f sea tu rtle s population in East M alaysia and the South China Sea. ]n K. Björdal
(ed.): Biology and conservation o f sea turtles. Proc. W orld Conf. Sea Turtle Conserv., W a sh ..P.C., 2630 Nov. 1979: 327-37
D iaz-M ., L., e t a l., 1989. C a racte rística s bio m é trica s de las tortugas Lepidochelys olivacea y D erm och elys coriacea,
anidadoras del Playón de M exiquillo,
Mich. VI Encuentro ¡nteruniversitario sobre tortugas marinas,
Facultad de Ciencias, UNAM, Mexico. (Abstract)
Discovery
Dom antay,
Center Inc., 1987. Sea turtle conservation Project, Broward County, Florida,
Erosion Prevention District, Fort Lauderdale, Florida. 1987 Report:26 p.
J.S.,
1952-53.
Donoso-Barros, R., 19 6 4.
----------------------------- ,
1966.
1987 Report. Broward County
The turtle fisheries o f the Turtle Islands. Bull.Fish.Soc.Philippines,V ol.3
Anotaciones sobre la s
tortugas m arinas de Venezuela.
&4: 1-27
Lagena, 3:26-31
R eptiles de Chile. Santiago, U niversity o f Chile, 458 p.
Dood, Jr., C .K., 1988. Synopsis o f the biological data on the loggerhead sea turtle Caretta caretta (Linnaeus 1758). US
F ish.W ild l.S e rv.B io l.R e p ., 88(4): 110 p.
Dupuy, A .R .,1986.
The status o f m arine tu rtle s in Senegal. M ar.Turtle N ew sle tte r,
39:4-7
Duran,
N.J.,
1989.
Anidación de la tortuga Carey Eretmochelys im bricata (Linnaeus 1766) en Isla Flolbox, Q. Roo.,
M e x ic o . VI E n c u e n tro in te ru n iv . s o b re to rtu g a s m a rin a s . F a c u lta d de C ie n c ia s , U N A M , M e x ic o ,
(Abstract)
Eckert,
K.L.,
1987. Environm ental u n p redictability
F lerpetologica, 43(3):315-23
Eckert,
K.L. & S.A. Eckert, 1988. Pre-reproductive m ovem ents o f leatherback sea tu rtle s
nesting, in the Caribbean. Copeia, 1988(2):400-6
Eckert,
K.L. & C. Luginbuhl, 1988.
and
leatherback
sea
tu rtle
Death o f a giant. M ar.Turtle N ew sletter,
D erm och elys
coria ce a
nest
loss.
(D erm ochelys coriacea)
43:2-3
Ehrhart, L.M . & B.E. W ith e rin g to n , 1986. Fluman and natural causes o f m arine turtle nest and hatchling m ortality
and th e ir relationship to hatchling production on an im portant Florida nesting beach. Florida Game
and Freshwater Fish Com. Nongame W ildlife Program. Tech-R ep., 1:141 p.
E isenberg,
J.F.
& J. Frazier,
Herpetology,
1983. A leatherback turtle
17(1 ):81 -2
(D erm ochelys coriacea) feeding
in the
wild.
Journal o f
Ferreira de M enezes, M., 1968. Sôbre alim entaçâo da arauanâ, Chelonia m ydas Linnaeus, ao longo da costa do Estado
do Ceará. A rg .Est.Biol.Mar., U n iv.F ed .C e a rá , 8(1 ):83-6
_________________ 5 1972. A s tartarugas m arinas do
Fletemeyer,
J.,
1984.
Brasil. A rq.C ien.M ar.F ortaleza, 12(1 ): 17-20
Sea turtle monitoring report. Broward County Environmental Quality Control Board. 72 p.
----------------------------- , 1985. Sea turtle monitoring project report. Subm itted to Broward County, Florida. Environm ental
Quality Control Board, Florida, 25 p.
Frazer, N.B. & L.M. Ehrhatt, 1985. Prelim inary grow th m odels for
caretta, turtles in the wild. C opeia, 1985(1 ):73-9
Frazier, J.,
1971.
green,
C helonia
m yd as and loggerhead, C aretta
O bservations on sea tu rtle s at Aldabra Atoll. Phil. Trans. R. Soc. Lond., (B)
----------------------------- , 1975.
260:373-410
Marine turtles o f the W estern Indian Ocean. Rep, from O ryx, 13(2): 164-175
----------------------------- , 1975a. The status o f know ledge on m arine tu rtle s in the W estern Indian Ocean. East A frican W ildlife
Society. M arine Turtle Survey. 10 p.
----------------------------- ,
1976. Sea
tu rtle s in Tanzania. Tanzania Notes and R ecords, 77-78: 11-20
65
Frazier, J., 1979.
Niche separation in Indian Ocean Turtles. Am erican Z oo lo g ist. 19(3):955
----------------------------- ,
1980. Exploitation o f m arine turtle
in the
Indian Ocean. Human Ecology. 8(4):329-70
----------------------------- ;
1981. Status o f sea turtles in Central W estern Indian Ocean. ]n K. Björndal (ed.): Biology and conser­
vation o f sea turtles. Proc. W orld Conf. Sea Turtle Conserv., W ash., P.C., 26-30 Nov. 1979: 385-90
----------------------------- , 1981a. Sea turtle hunts thro u g h o u t the w orld.
Education. 16 p., 1 map.
Sea
Turtle
Rescue
Fund-C enter for Environm ental
----------------------------- , 1983. A nálisis estadístico de la tortuga golfina Lepidochelys olivacea (Eschscholtz) de Oaxaca, Mexico.
C iencia P esquera, 4:49-75
----------------------------- ;
1984. Las tortugas m arinas en el Atlántico sur occidental. Asoc. Herpet. Arqetina, Ser.
----------------------------- ,
1985. M arine tu rtle s in the Com oro A rchipelago. North Holland Pub. Co., Am sterdam ,
York. 177 p. XVIII pit.
D iv., 2:21 p.
Oxford, New
----------------------------- , 1985. M isidentification o f sea turtles in the East Pacific: C aretta caretta and Lepidochelys olivacea.
Journal o f Herpetology, 19(1 ):1 -11
Frazier, J. & S. Salas,
----------------------------- ,
1982.
Tortugas m arinas en Chile.
B o l.M u s .N a c .H is t.N a t.C h ile ,
1983.The marine turtle situation in the East Pacific.
C.D.C.
39:63-73
Newsleter, 2(1 ):7-10
----------------------------- ; 1983a. Tortugas m arinas del
Pacifico oriental:
El recurso que nunca acabara?
[n :
Sim posio
Conservación y Manejo Fauna Silvestre Neotropical. IX
C ong.Lat. Am. de Zoología. 9-15 Oct. Perú,
1983: 87-98
----------------------------- ; 1984. The status o f marine turtles in the Egyptian Red Sea. B iol.C onserv., 30(1984):41-67
Frazier.J., M. M enechel & F. A chaval, 1985. A clarification on the feeding habits o f D erm och elys coriacea. Journal
o f Herpetology, 19(1): 159-60
Fretey, J., 1986. Le statut des tortues m arines en Guyane Française.
Le Littoral G uyanais
(Sepanguy Sepanrit): 179-90
----------------------------- ,
1987.
Les tortues de Guyane Française: Données récentes sur leur systém atique, leur b io g é o g ra p h ie ,
leur ethologie et leur protection. Nature G uvanaise Sepanguy, 141 p.
_________________
1987a.
Nouvelle capture d ’une tortue luth (D erm ochelys coriacea) en Polynésie
Française. Bull.Soc.
Herp. Fr., 41:28-9
Fretey, J.
& M.
G iro n d o t,
1987.
Recensement des pontes de
tortue luth, Derm ochelys coriacea (Vandelii, 1761),sur
les plages de Ya:Lim a:P o - Les Hattes a Awara (Guyane Française) pendant la saison, 1986.
Bull. Soc.
Herp. F r.,4 3 :1-8
F re te y ,
&
Lebeau, 1985.
Capture d ’une tortue luth D erm och elys coriacea
Française. Bull. Soc. Herp.Fr., 33:37-42
J.
Fretey, J. & L.
A.
Polynésie
Sanite, 1986. Fonctionnement de l’écloserie d ’oeufs de tortues luths des hattes - Ya: Lima: Po (Guyane
Française), Le Littoral Guyanais (Sepanguy Sepanrit): 191-6
Fritts, T.H., 1981.
M arine turtles o f the G alapagos Islands and adjacent areas o f the Eastern Pacific
observations made by J. R. Slevin 1905-1906. Journal o f Herpetology, 15(3):293-301
Fritis, T.H ., 1982. Plastic bags in the intestinal tracts o f leatherback m arine turtles.
Fritts, T.H., & W. Hoffm an, 1982. D iurnal nesting
H e rpe to lo g y, 16(1 ):84-6
G ard uñ o,
(V a n d e lii,1 7 6 1 ), en
A .M .,
G arm an, S., 1 8 8 0.
o f m arine tu rtle s
in Southern
1983.
Algunos aspectos de la protección de la tortuga de
1766) en las costas de Cam peche. M ex.(Tesis Prof.), 76 p.
On certain species o f Chelonioidae.
Carey,
on the basis o f
Herpetological R ev., 13 (3), 72-3
Brevard
C ounty,
Eretm ochelys
Bull. Mus. Com p Z o o l., 6(6):123-6
Florida. Journal o f
im bricata
(Linnaeus
66
G arm an, S., 1908. R eports on the scie n tific results o f the expedition to the
Easter Island.
Bull. Mus. Comp. Z o o l., 52(1 ):14 p.
Eastern T ropical Pacific. The reptiles o f
Garnet, M. & J. Frazier, 1979. Eretm ochelys breeding biology in the Seychelles. Am erican Z o o lo g ist. 19(3):517
G eldiay, R., T. Koray & S. Balik, 1981. Status o f sea tu rtle s populations (C aretta c. caretta and Chelonia m. m ydas) in
the northern M editerranean Sea, Turkey. Jn K. Björndal (ed.): Biology and conservation o f sea turtles.
Proc.World Conf.Sea Turtle Conserv., Wash., D.C.. 26-30 Nov. 1979:425-33
G il-H ern án d ez.R .A ., 1988. Biología y conservación de las tortugas m arinas en el litoral central de Quintana Roo,
México. Informe final 1987. CIQRO, 84 p.
G ram entz, D .,1988. Involvem ent o f loggerhead tu rtle w ith the plastic,
M e d ite rra n e a n . Reports Mar. Poll. B ull., 19(1 ):11-3
G rassm an, M.A.
G reen, D., 1984.
Green,
D.
m etal and hydrocarbon
& D.W . O w ens, 1982. D evelopm ent and extinction
tu rtle , Caretta caretta. C o p e ia , 1982(4):965-9
Long-distance m ovem ents o f Galapagos green turtles.
o f food
pre fe re nce s
p ollution
in
the
in the
Central
loggerhead
sea
Journal o f H erpetology, 18(2): 121-30
& F. O rtiz-C respo , 1981. S ta tu s o f the sea tu rtle p o p u la tio n s in the C entral Eastern P acific, Jn K.
Björndal (ed.): Biology and conservation o f sea turtles. Proc. W orld Conf. Sea Turtle Conserv., W ash.,
D.C., 26-30 Nov. 1979:221 -3
Groom bridge, B.,
1982. The IUCN A m phibia-R eptilia Red Data Book. Part. 1. Testudines, Crocodylia, R hynchocephalia.
IUCN. Gland, Sw itzerland, 426 p.
G udger, E.W., 1919. On the use o f the sucking fish for catching fish and turtles: Studies in Echeneis or rém ora, II.,
A m e r.N a t., 53(628):446-68
Flays-Brow n, C., & W .M . Brow n, 1981. Status o f sea tu rtle s in the southeastern Pacific: E m phasis on Peru, jn K.
Björndal (ed.): Biology and conservation o f sea turtles. Proc.W orld Conf.Sea Turtle Conserv., W ash.,
D-C., 26-30 Nov. 1 9 7 9 :235-40
H endrickson, J.R ., 1961. Conservation
214-23
-----------------------------; 1962. The
Hirth, H.F., 1971.
investigations on M alayan turtles.
leathery tu rtle .
M alayan
Nature Journal (Special Issue):
Oryx , 6(6):335-7
Synopsis o f biological data
S yn o p sis, FIR M /S85:75 p.
on the
green tu rtle
C h elo nia m yd as (Linnaeus)
1758.
FAQ
F isheries
Hirth, H.F. & A.F. Carr, 1970. The green turtle in the G u lf o f Aden and the Seychelles Islands. Verh. K. Ned. Akad. W et.
(Afd. Nat. Tweede S ect.), 58: 1-44
Hirth, H.F. & L.H. Ogren, 1987. Some aspects o f the ecology o f the leatherback turtle D erm och elys coriacea at Laguna
Jalova, Costa Rica. NOAA Tech. Rep. N M F S , 56: 14 p.
Hoffm an, B.A. & W .J. Conley, 1987. Update: Nesting A ctivity o f Florida sea turtles. Jn VII A n n u a l W o rksho p
Turtle Biology and Conservation. 25-27 Feb. 1987, W ekiwa, Park, Florida. Posters Sessions, 1 pit.
Hoffm an, W . & T.H . Fritts, 1982. Sea turtle d istribution along the
Florida.
H e rpetologica, 39(3):405-9
boundary o f the G u lf Stream
on
Sea
current o ff eastern
Honna, Y. & S. Yoshie, 1975. A record o f the Pacific ridley turtle Lepidochelys olivacea, from the coast o f Niigata facing
the Japan Sea, w ith description o f som e o f the organs. A n n .Rep.Sado M a r.B io l.S ta t.N iig a ta U n iv.,
5 :1 -g
H opkins,
S .R., e t
a l ., 1971. Biotic and a b io tic fa cto rs affecting nest m ortality in the A tla n tic loggerhead turtles. Jn
R.W. Dim m ick (ed.): Proc. Thirty Second A nnual C onf.S outheastern A ssoc.F ish & W ildlife Agencies. SE.
A ssn.:
213-23
Horrocks, J.A., 1987. Leatherback in Barbados.
M a r.T u r tle
N ew sletter, 41:7
67
Hubbs, C .L., 1977. First record o f m ating ridley tu rtle s in
system atics. Calif.Fish G am e, 63(4):262-7
California,
Hughes, G.R., 1974. The sea tu rtle s o f south-east Africa. I. Status,
A fr.In vest.R e p ., 35:144 p.
with
notes on
com m ensals,
m orphology and d istribution.
characters and
O c.R es.Inst.S outh
----------------------------- , 1975. The marine turtles o f Tongaland, VIII. The Lam m ergeyer, October. 22:9-18
----------------------------- , 1977. Sea tu rtle s - a sim ple guide to the Southern A frican sp ecies w ith notes o f interest on th e ir
general biology, m igrations and conservation status. Natal Parks Board, Pieterm aritzburg, South
Africa, 24 p.
----------------------------- ;
1981. C onservation o f sea tu rtle s in the Southern A frica region. In K. Björndal (ed.): Biology and
conservation o f sea turtles. Proc W orld Conf.Sea Turtle Conserv., W a sh .,D C . 26-30 Nov. 1979:397-404
Hughes, Gr. &M .T. M entis, 1967. F urther stu d ie s on m arine tu rtle s in T ongaland, II. The Lam m ergeyer,
3 (7 ):5 5 -7 2
Hughes.G .R ., A .J. Bass & M .T. M entis, 1967. Further studies on m arine tu rtle s in Tongaland, I. The Lam m ergeyer,
3(7): 1-54
H u rtado , M.,
1984.
Registros de anidación de la tortuga negra, Chelonia m ydas en las Isias Galápagos. Bol.Científico y
Técnico, Guayaquil. Ecuador, 6(3):77-106
H u rtado , M., G. Corrales & K. Muentes,
1981.
Participación de estudiantes universitarios en el program a de tortugas
m arinas. Instituto Nacional de pesca. G uayaquil, Ecuador.Bol.Inf.,
2(5):24-9
Kam ezaki, N.,1986. Notes on the nesting o f the sea turtles in the Yaeyam a Group,Ryukyu Archipelago. Japanese J. o f
Herpet., 11 (3): 152-5
----------------------------- ;
1987.
Recapture o f the hawksbill turtle E retm och elys im bricata (Linné), in the Yaeyam a Islands,
Ryukyu Archipelago. G alaxea, 6 : 17-20
K am ezaki, N. & H. Yokochi, 1986. A record o f casting juvenile hawksbill turtle
Inom otejim a Island. A k a m a ta , 3:9-10
Eretm ochelys im bricata upon the
Kar, C.S. & S. Bhaskar, 1981. Status o f sea turtles in the Eastern Indian Ocean. In K. Björndal (ed.): Biology and conser­
vation o f sea turtles. Proc.W orld Conf.Sea Turtle Conserv., W a sh ., DC, 26-30 Nov. 1979: 365-72
Kaufm an,
R., 1966. Das Vorkom m en von
und M useum , 96(2):449
----------------------------- ,
----------------------------- ;
M eeresschildkröten
in Kolum bien
1971. Report on status o f sea turtles in Colom bia.
1972. W achstum sraten in G efangenschaft
Alem án Invest.Cient., 6 : 105-12
und
Nutzung als
N ahrungsquelle.
N a tu r
IUCN Publ. (ns.), Suppl.Pap., 31:75-8
gehalte n e r
M eeresschildkröten.
I.
M itt.Inst. C olom bo-
----------------------------- ; 1973. Biología de las tortugas m arinas Caretta caretta y Derm ochelys coriacea, de la costa Atlántica
colombiana. Rev.Acad.Colombiana de Ciencias Exactas, Fisicas y Naturales, 16(54):67-80
----------------------------- ^1975. Studies on the loggerhead sea turtle Caretta caretta caretta (Linné), in Colombia, South America,
H erpetologica, 31 (3) :323-6
Khan, M .A.R..
1982. Chelonians o f Bangladesh and th e ir conservation. Journal Bom bay N at.H ist.S oc., 79(1): 110-6
Kondo, Y ., 1968. Aka umi game Caretta caretta olivacea (Eschscholtz) prelim inary survey o f nesting loggerhead t u r t le s
in the beach o f Hiwasa. Japan-Private Print, Japan. 96p (in Japanese)
Kow arski, J.,
1978. O bservations on green tu rtle s (C helo nia m ydas) in N ortheastern A ustralia during the 197 5/7 6
nesting season. Biol. C onserv., 13:51-62
Kuan-Tow , S.,
1988. Proposed strategy for sea turtle conservation in M alaysia. Int. Symp. on Sea T urtles in Hiawasa
1988. Marine Turtle Specialist Group/IUCN, Hiwasa Com munity Center. (Abstract)
68
K uan-Tow ,
Kurata,
S.
&
E.O. M oll, 1981. Status and conservation o f estuarine and sea turtles in the W est M alaysia waters.
In K. Björndal (ed.): Biology and conservation o f sea turtles. Proc. W orld Conf. Sea Turtle C o n se rv.,
Wash., P.C., 26-30 Nov. 1979: 339-47
Y., e t al.,
1978.
E xperim ents to increase n u m bers o f green sea tu rtle s th rough the release o f the young (VII.
Aoum igam e Sosho-ku Horyu Shinken). O gasaw ara Fish.C enter, T okyo M et. Gvn., Res. R e p ., 3 :5 8 -8 0
(Japanese,Trad.: Tamio Otsu), Southwest Fish. Center, Flonolulu Lab., NMFS, 1981,27 p.
Kuriyan, G.R., 1950. Turtle fishing in the sea around Krusadai Island. Journal Bombay Nat. Hist. S o c.,
Kushlan, J.A.,
Lazell,
1986. A tla n tic
L.D., 1979.
loggerhead
turtle
Boreal and tem perate
nesting
status
in
Southw est
Florida.
Flerpetological
49:509-12
R e v., 17(2):51 -2
m igratory regim es o f A tla n tic m arine turtles. Am erican Z o o lo g is t, 19(3):
953 (Abstract)
Lebeau, A., 1986. Un essai de grossissem ent en captivité de la tortue verte Chelonia m ydas réalisé a Tahiti (Polynésie
Française). Rev. Trab. Inst. Peches M arit., 48(3-4): 143-54
Le Poulain, F., 1941. Note on the sea o f the G ulf o f Siam, jn T o rtu e s de L’Indochine. Note by L. Bourret.
Indochine Stn. Marit. Cauda, Nhatrang, 38:215-8
Lewis, C.8.,1940.
Limpus, C.,
1971.
Inst. O c é a n o g r.
The Cayman Islands and marine turtles. Bull.Inst. Jamaica. Science Series, 2 :5 6 - 6 5
The flatback turtle, Chelonia depressa Garman, in southeast Queensland, Australia.
27(4):431-46
F le rp e to lo g ic a ,
----------------------------- , 1978. The reef: uncertain land o f plenty. In H.J. Lavery (ed.): Exploration north, a natural history o f
Q ueensland. Richm ond Hill Press, Richm ond, Victoria, A ustralia, 249 p. (pages 187-222)
----------------------------- , 1980.
New
national
parks
protecting
turtle
habitat
in
Q ueensland.
Mar.
Turtle
N e w sle tte r, 15:11-2
_________________ 5 1981. The status o f Australian sea turtle populations. In K. Björndal
(ed.): Biology and conservation
o f sea turtles.
Proc. W orld Conf. Sea Turtle Conserv., Wash., D. C., 26-30 Nov. 1979: 297-303
----------------------------- , 1984. A benthic feeding
C o p e ia , 1984(2) :552-3
----------------------------- , 1986.
record
Sea Turtles. O ceans
from
neritic w a te rs
for leathery tu rtle
(D erm ochelys c o ria c e a ).
29(2):98-9
----------------------------- , 1987. Sea Turtles, jn J. Covacevich et al. (eds): Toxic Plants and Anim als. A guide for Australia, (pages
188-93)
Limpus, C. &
P.
Reed, 1985. The loggerhead tu rtle , C a re tta caretta,
behaviour. A ust. W ildi. Res., 12:535-40
in
Q ueensland:
observations on
internesting
Limpus, C., A. Fleay & V. Baker, 1984. The flatback turtle, C helonia depressa, in Q ueensland: reproductive periodicity,
phylopatry and recruitm ent. A ust.W ild i.R es., 11:579-87
Limpus, C., E. Gyris & J. M iller, 1988. R eassessm ent o f the ta xo n o m ic sta tu s o f the sea tu rtle ge n us N a t a t o r
M ccullo ch, 1908, with a redescription o f the genus and species. Transactions o f the Roval Society o f
South A u stra lia , 112:1-9, pit.I
Limpus,
C., J, M ille r & A. Fleay, 1981. The o live rid le y
Q ueensland. Flerpetofauna, 12(2):2-3
Limpus,
C.,J. Miller, V. Baker & E. McLachlan, 1983. The h a w ksb ill tu rtle E re tm o c h e ly s im b ric a ta (L.), in n o rth ­
eastern Australia: The Campbell Island Rookery. Aust.W ildl. R es., (10): 185-97
Lim pus,
C.e t al., 1983a. The Crab Island sea turtle
Res., 1983( 10) : 173-84
1983b.
tu rtle
rookery
L e p id o c h e ly s
in the
The flatback turtle Chelonia depressa
in
north-eastern
Q ueensland;
g ro u n d d is trib u tio n . A u st. W ild i.R e s .,1983(10):557-61
o liv a c e a
reco rd e d
from
south
G u lf o f Carpentaria. Aust. W ild.
post-nesting
m igration
and
feeding
69
-----------------------------, (in press).
The sea turtle rookeries o f north western Torres Strait.
Austr.Wildl.Res.
Loveridge, A. & E. W illiam s, 1957. Revision o f the A frican to rto ise s and tu rtle s o f the suborder Cryptodira. Bull. Mus.
Comp. Zool., Harvard Univ.. 115(6):161 -557
M aigret, J., 1983. R epartition des tortues de m er sur les
côtes ouest Africaines.
-----------------------------, 1986. Statut actuel des tortues de m er en
M a rg a rito u lis ,
D.,
1983.
The
in te r-n e stin g
interval
of
Mediteranée.
Z a kyn th o s
Bull. Soc. Herp. Fr.. 1983(28):22-34
Rapp. Comm, int. Mer M éd it., 30(2):243
loggerheads.
In
N.S. M argaris et al. (eds):
Adaptation to terrestrial environm ents. Plenum Press, New York (pages 135-44)
-----------------------------, 1985.
Prelim inary o b servations on the breeding behaviour and ecology o f C aretta c a retta in
Zakynthos, Greece. In 2®me Cong. Int. sur la Zoogéographie et L’Ecologie de la Grèce etdes Regions
avoisinantes. Athènes, Sept. 1981. Biologia Gallo-Hellenica, 10:323-32
-----------------------------, 1986.
C aptures and strandings o f the leatherback sea turtle D erm ochelys coriacea, in Greece (19821984). Journal o f Herpetology,
20(3):471-74
M argarito ulis, D.,
T. A rapis, E. Kornaraki & C. M ytilineo u, 1986. Three specim ens o f the
m ydas (L.), recorded in Greece. Biologia G a llo -H ellen ica , 12:237-43
M arquez M., R.,
1970.
green sea turtle
Chelonia
Las to rtu g a s m arinas de M exico. (Tesis pro ms), 184 p., 22 figs.
-----------------------------, 1978. Sea turtles. In W. Fischer (ed.): FAO species identification sheets for fishery purposes. W estern
Central A tlantic (fishing area 31), V ol.6 , FAO, Rome, Italy
,
1978a. Natural reserves for the conservation o f marine turtles o f Mexico.
60
Fia. Mar.Res. Pub.,
33:56-
;
1981. Sea turtles. \n \N . Fischer, G. Bianchi & W .B. Scott (eds): FAO species identification sheets for
fishery purposes. Eastern Central Atlantic (fishing area 34 and part o f 47).
Vol.6 , FAO, Rome, Italy
;
1984. Sea tu rtle s.
In W. Fischer & G. Bianchi (eds): FAO species identification
purposes. W estern Indian Ocean (fis h in g a re a 51), Vol.5, FAO, Rome, Italy
sheets for fishery
M arquez
M., R.,
& M .-L . B a u c h o t, 1 9 8 7 .
Tortues. In W. Fischer, M .-L. Bauchot & M. S chneider (eds): Fiches FAO
d ’identification des especes pour les besoins de la pêche (révision 1). M editerranee et M er Noire. Zone
de p ê c h e 37. Vol.2. Vertébrés: 1422-38, FAO, Rome, Italy
M arq u e z
M., R.
& T. Doi,
1973.
Ensayo teórico sobre el análisis de la p o b la c ió n de tortuga prieta, Chelonia mydas
carrinegra Caldw ell, en aguas del Golfo de California, Mexico. Bull.Tokai Reg.Fish. R es.Lab., 73: 1-22
M arquez
M., R., & T.H . Fritts, (in press). P ro sp e cció n a e re a para tortugas m arinas en la costa m exicana del Golfo de
Mexico y Caribe, 1982-1983, subm itted to Ciencia Pesquera, INP-M exico, 18 p.
M árq u e z M., R. & H. G . Van Dissel, 1982. A m ethod fo r eva lu a ting the num ber o f m assed nesting olive ridley
sea turtles, L ep ido chelys olivacea, during an arribazón, with com m ents on arribazón behaviour.
Netherlands Journal o f Z oo lo g y,
3 2 (3 ):419-25
M arquez M., R.,
A . V illanu eva & C. Pen aflo res, 1976. S inopsis de d a tos bio ló g ico s sobre la to rtu g a
Lepidochelys olivacea (Eschscholtz. 1829). INP, Sinopsis sobre la Pesca (IN P /S 2,SAST), 2:61 p.
golfina
M arquez
M., R.e t al., 1981. A m odel for diagnosis o f the population o f olive ridleys and green tu rtle s o f W est Pacific
Tropical coasts. Jn K. Björndal (ed.): Biology and conservation o f sea turtles. Proc. W orld Conf. Sea
Turtle Conserv., W ash., D.C., 26-30 Nov. 1 979: 159-64
M artinez,
E.D.,
M atos. R., 1986.
1984. C aretta c a retta c aretta (L.) en
C orrientes A rg e n tin a . 4(21 ):20 9 -1 2
la
Bahia
Blanca,
A rgentina,
(C heloniidae)
(1).
Historia
Nat.
Sea turtle hatchery project with specific reference to the leatherback turtle (D erm ochelys coriacea).
Flumacao, Puerto Rico, 1986 Natural Reserves R efuges Division, Departm ent o f Natural Resources,
24 p. (ms)
70
M cA llis te r,
M cC ann,
H J .,
C.,
A .J. Bass & H J . van Schoor,
The Lamm ergeyer, 3(2): 10-40
1966. The m arine
5(21 ):201 -15
tu rtle s
and
1965. The
snakes
m arin e
occurring
in
tu rtle s
New
on
Zealand.
th e
co a st
of
T o n g a la n d ,
N atal.
Rec.Dorn.M us. (W e llin g to n ),
M cC onnaughey, B.H., 1978. Introduction to marine biology. The C.U. M osby Co., 3rd ed., 624 p.
M cC oy,
M .A .,
1974.
Man
and tu rtle
in the
Central
Carolines.
R eprinted
from
M icro n e sva . 10121:207-21
M cGeehe, M.A.,
1979. Factors affecting the hatching success o f loggerhead sea turtle eggs ( C aretta c a re tta caretta).
M.S. thesis, University o f Central Florida, Orlando, 252 p.
M en d on ça, M .T .,
1981. Com parative growth rates o f wild im m ature
Journal o f H e rpe to lo g y, 15:447-51
,
1983. M ovem ents and feeding ecology
Lagoon. Copeia, 1983(4): 10 1 3-2 3
C helonia m ydas and C aretta caretta in Florida.
o f im m ature
green
tu rtle s
(C helo nia m ydas)
M endonça, M .T .
& L.M. Ehrhart, 1982. A ctivity, population size and structure o f im m ature
Caretta caretta in M osquito Lagoon, Florida. C opeia, 1982(1 ): 161 -7
M enezes,
1976. A s ta rta ru ga s m arinhas do
M eza,
M.F.,
C h .B .F.,
M e y la n ,
Brasil. Arg.
Cien. M a r., 12(1):
in
Florida
Chelonia m ydas and
17-20
1989.
Presencia de tortuga Carey E retm ochelys im b ricata. Playa Platanitos, Nay. Méx. VI Encuentro
Interuniv. sobre T ortugas Marinas. Fac. Ccias. M arinas. (Abstract)
A .B ..
1983. M arines tu rtle s o f the
Leeward
Islands,
Lesser A ntilles. Atoll Res. B ull., 278:43p
-----------------------------, 1985. The role o f sponge collagen: in the diet o f the haw sksbill tu rtle E retm och elys im b ric a ta .
(eds A. Bairati and R. G arrone) Plenum Publ. Corp., G ainesville, FI., USA.: 191-6
5
,
M illik e n .T .
&
1988.
Spongivory in haw ksbill turtles: A diet o f glass. S cie n ce , 239: 393-5
1989. Hawksbill turtle (Eretmochelys imbricata). Status Report. Jn L. Ogren et al. (eds): Proceedings
Second W estern A tla n tic Turtle Sym posium . M ayaguez, P .R., 12-16
Oct. 1987. NOAA T ech .M e m .,
NM FS -S EFC -226;101 -21
H. Tokunaga., 1987. A special report prepared by TRAFFIC (Japan). W .W .F. Center for Environm ental
Education. W ashington, D.C., 171 p.
M oh anty-H ejm ad i, P. & M. Dim ond. 1986. Tem p e ra tu re d e p en d e n t
Progress in Developm ental Biology, part A: 159-62
sex
d e term in a tion
in
the
olive
ridley
turtle.
M o h a n ty -H e jm a d i, P., M. Behera & M. Dim ond, 1985. T em perature dependent sex d ifferentiation in the olive ridley
Lepidochelys o livacea and its im plications for conservation. Proc. Symp. Endanaered M arine A nim als
and M arine Parks. C o ch in , India, 1:260-3
M oiseev,
P.A ..
1971. The living resources
T ranslation Ltd., 334 p.
Montenegro, S.B.,
M o re ira
A .,&
o f the
w orld
ocean.
NM FS -N O A A,
Israel
Program
for
S cientifical
N .G . Bernal & A. M artin e z G., 1986. Estudio del co ntenido esto m a ca l de la to rtu g a m arina
Lepidochelys olivacea, en la costa de Oaxaca, Méx. An. Inst. Cienc. del Mary Limnol. U N A M , Mexico.,
13(2): 121 -32.
M . B enitez, 1986.
Informe Nacional - El Salvador,
in R, M árquez et al. (eds): I Simp. Tortugas M arinas
Pac. Amer. San Jose, C .R., 2-6 Dic., 1985. (Abstract)
M ortim er, J. A.,
1981. The feeding ecology o f the W est Caribbean
Biotropica,
13(1 ):49-58
M ro so vsky,
1971.
N.,
Black vu ltu re s attack
live turtle
hatchlings.
green turtle
(C helo nia m ydas) in
The A u k , 88(3):672-3
1983. Conserving sea turtles. The British Herpetological Soc. o f London, 176 p.
N icaragua.
71
M usick, J. e t al., 1983. M ortality and behaviour o f sea tu rtle s in the Chesapeake Bay. Sum m ary Report for 1979 through
1983. Virginia Institute o f M arine Science, Contract NA80FAC00004. Subm itted to NM FS-Northeast
R egion, 102 p.
N at.Fish. & W ildlife Lab., 1980. Selected vertebrate endangered species o f the seacoast o f the
United States - green
sea turtle. Biological Services Program , F W S /O B S -80/01. 13:9 p.
N elson, E
W,
1966. Lower California and its Natural Resources. Reprod. of: E. W. N elson’s, 1922. National
S e i., XVI. (First M em oir), 194p.
Acad.
N ietschm ann, B.,
1981. Following the underw ater trail o f a vanishing species - the hawksbill turtle. Nat.Geogr. Soc. Res.
R eports. 13:459-80
N ishim ura, S.,
1967. The loggerhead tu rtle s in
Seto. Mar. Biol. Lab., 15(1): 19-35
O gren, L.,
Draft national report for the country o f Colom bia, Jn P. Bacon et al. (eds): W estern A tla n tic
Sym posium , 17-22 July, 1983. Sn. Jose, Costa Rica, 3: 123-30
1983.
O g re n , L., & C.
Japan
and
neighboring
Parm enter,
P ascual, X.,
(Testudinata:
C heloniidae).
Publ.
Turtle
McVea (Jr), 1981. A pparent hibernation by sea turtles in North Am erican w ater. Jn K. Björndal (ed.):
Biology and conservation o f sea turtles. Proc. W orld Conf. Sea T urtles C onservation. W ash., D.C., 26-30
Nov. 1979: 127-32
O gren, L.H .,J.W . W atso n (Jr) & D.A. W ickham , 1977. Loggerhead
tra w ls . M arine Fisheries Review , 1270: 15-7
O liver, J.A .,
w a te rs
1946.
An
aggregation
o f Pacific sea turtles.
C.J., 1983. R eproductive m igration
in the
sea turtles,
C aretta caretta, encoutering
shrim p
C o p e ia , 1946(2): 103
haw ksbill tu rtle
E retm och elys im b ricata. C o p e ia , 1983(1 ):271 -3
1985. Contribución al estudio de las tortugas m arinas en las costas españolas. I. Distribución.
9: 287-94
Mise. Z o o l.,
Peters, J.A., 1954. The am phibians and reptiles o f the coast and coastal sierra o f M ichoacan, Mexico. Occ. Papers MUS.
Zool. Univ. M ich ., 554: 1-37
P h a s u k , B .,
Polunin,
&
S. Rongm uangsart, 1973. Growth studies on the olive ridley turtle, Lepidochelys o livacea olivacea
E sch sch o ltz, in c a p tiv ity and the e ffe ct o f food p re fe re n ce on g ro w th . P huket M a r.B io l.C e n t.R e s .B u ll.,
1:14p.
N.V.C .,
1975. Sea turtles. Reports on Thailand, w est M alaysia and Indonesia, with a synopsis o f data on the
conservation status o f sea tu rtle s in the Indo-W est Pacific region. Dep.of Zoology, C am bridge, 113 p.
(ms)
Polunin, N .V.C.
& N. Sum ertha-N uitja, 1981. Sea tu rtle s populations o f Indonesia and Thailand. In IC. Björndal (ed.):
Biology and conservation o f sea turtles. Proc. W orld Conf.Sea Turtle Conserv., W ash., D.C., 26-30 Nov.
1 9 7 9 : 353-62
Pope, C .H., 1935.
The reptiles o f China - turtles, crocodilians, snakes, lizards. Natural History o f Central Asia. V o l.10.
A m e rican M useum o f N atural H istory, New Y o rk, 6 04 p.
Pritchard, P.C.H.,
1966.
----------------------------- , 1969.
Sea turtles o f Shell Beach, British Guiana. Copeia. 1966(1 ): 123-5
Sea tu rtle s o f the G uianas.
Bull. Fia. State Mus., B io l.Sei.,
13(2 ):8 5 -1 40
----------------------------- , 1971.
G alapagos sea tu rtle s: p re lim in a ry findings.
----------------------------- , 1971a.
Sea tu rtle s in the G alapagos. Paper 4. IUCN P ubl.(n.s.), S uppl.P ap., 31:34-7
----------------------------- , 1977.
M arine tu rtle s o f M icronesia. C helonia Press, San Francisco, 83 p.
1979.
Journal o f F ierpetology, 5: 1-9
E ncyclopedia o f tu rtle s. T.F.H. Publ., Inc., Jersey City, 895 p.
72
Pritchard,
P .C .H.
& P. Trebbau, 1984.
The turtles o f Venezuela.
2 :403 p., 47 pit., 16 m aps
Soc. Study Am ph. and Rept., Contrib. H erpetol.,
R a j, V ., 1 9 7 6 .
Incubation and hatching success in artificially incubated eggs o f the hawksbill turtle
im b ricata (L.). J. Exp. Mar. Biol. E co l., 22:91-9
R ajago palan, M .,
1983. Leatherback tu rtle D erm och elys coria ce a w ashed ashore at
inform ation Service, Special Issue on M anagem ent and C onservation Sea
Inst., Cochin, India. Tech. and Extension Series, 50:35-6
R am boux, A .C .,
1982. Program a de protección de las tortugas m arinas en la costa sur-oriental del Pacifico. Resultados
de la tem porada de 1981. A cuicultura Experim ental. G uatem ala. G ua/81/004 Doc, de C am po, 1:42 p.
Rebel, T.P. (ed.),
1974. Sea turtles and the turtle industry o f the W est Indies, Florida and G ulf o f Mexico. (Rev. ed. 1949
by R. M. Ingle and F.G .W .S m ith) U niversity o f M iami Press, Coral Gables, Florida, 250 p.
Rhodin, A .J.
& R.C. Schoelkopf, 1982. R eproduction data on a fem ale
stranded in New Jersey. C o p e ia , 1982(1 ):1 81 -3
Rhodin, A .J. &
leatherback turtle
Romer, A.S.,
studies
on
skeleton
m orphology
1956.
1972.
_________________
o f the
in the
leatherback
New Guinea
1985. Sexual d ifferentiation as a function o f the incubation tem perature o f eggs in the sea turtle
Derm ochelys coriacea (Vandelii, 1761). Am phibia-R eptilia, 6 (1985):83-92
Osteology o f the Reptiles.
Univ. Chicago Press, Chicago, 772 p.
R o sales-Lo essen er.F., 1985. Informe sobre la situacibn actual de las to rtu g a s m arinas de
G uatem ala. Min. de Agr. y Gan., Dir. Tec. de Pesca y Acuic., 9 p.
la costa del Pacifico de
Sea tu rtle s in the S u lta n a te o f O m an. Rep. for W orld W ild life Fund, (P roject. 1320). 54 p.
1981. Historical decline o f loggerhead, ridley and leatherback sea turtles. In K. Björndal (e d .):Biology
and conservation o f sea turtles.
19 7 9 : 189-95
5 1985.
Biology o f the green
’ H e rp e to lo g y , 19(4): 4 5 9 -6 8
Ross, J.P.
D erm och elys coriacea,
S . Spring & P.C.H. Pritchard, 1980. G lossary o f tu rtle ve rn a cu la r nam es used
re g io n . Jour.P olynesian Soc., 89(1):105-17
Rimblot, F. et al.,
Ross, J.P.,
Kovalam , M adras. M arine
Turtles. Central Mar. Res.
H.M. Sm ith, 1982. The original authorship and type specim en o f D erm och elys coriacea. Journal o f
H e rp e to lo g y, 16 (3 ):3 1 6-7
Rhodin, A.J., J.A. Ogden & G.J. Conlogue, 1980. Prelim inary
tu rtle . M a r.T u rtle N e w s le tte r, 1 6 :7-9
Rhodin, A . J . ,
Eretm ochelys
Proc. W orld
tu rtle
Conf. Sea Turtle
Chelonia
m yd as
on
an
Conserv., W ash.,
A rabian feeding
D.C., 26-30
ground.
Nov.
Journal
of
& M. A .B a rw a n i, 1981. R eview o f sea tu rtle s in the A ra b ia n Area, jn K. Björndal
(ed.): Biology and
conservation o f sea turtles. Proc. W orld Conf. Sea Turtle Conserv., W ash., D.C., 26-30 Nov. 1979: 373-83
Routa, R.A.. 1968. Sea turtle nest survey o f Hutchinson Island, Florida. Quart. J. Florida Acad. S ei., 30(4):287-94
Salas, F.S. et al. 1988. Sea T urtles in Fujian and G uangdong Provinces. Acta Herpetologica S in ica , 1983(3): 16-46
Schafer,
E.F.,
1962.
S c h le ic h , H .H .,
Eating
in
1987. C on trib u tio n s
Spixiana 10(1 ):37-80
----------------------------- , 1987a.
S chroeder,
tu rtle s
ancient
to
the
China.
J.
herpetology
Am er.
of
O riental
K ouf
S o c., 82(1 ):73-4
National
Park
(N E- Libya)
and
ad ja ce nt
areas.
H erpetofauna C a boverdiana. Spixiana (sup p le m e n t) 12: 1-75
B.A., 1987. Sea tu rtle stranding and salvage netw ork A tla n tic and G u lf C oasts
NMFS - C oastal R esources D iv ., C ontr. No. C R D -87/88-12, 45 p.
of
the
United
States.
73
Schroeder, B.A. & A. A. W arner, 1988. Annual report o f the sea turtle stranding and salvage netw ork A lta n tic and
G ulf Coasts o f United States, January-D ecem ber 1987. NM FS-Coastal Resources D iv., Contr. NO. CRD8 7 /8 8 -2 8 .4 5 p.
Schulz, J.P.,
1975.
Sea tu rtle s
nesting
in
Surinam .
Nederl.
Com m.
Internatl.
Natuurbesch.
M e d e d ., 23:
143
p.
_________________ ; 1984.
Turtle conservation strategy in Indonesia. Report to D irektorat Pelestarian Alam o f the
D irektorat Jendral P erlindungan Hutan dan P elestarian Alam . D epartem en Kehutanan, Bogor.
IU C N /W W F , 105 p. (m s)
Schw artzs, F.J., 1974. The m arine leech O zobranchus m a rg o i (Hirudinea: Pisciocolidae), epizootic on Chelonia and
Caretta sea tu rtle s from North C arolina. The Journal o f P a ra sito lo g y, 6 0 (5 ):8 89 -9 0
Seale, A., 1911.
The fishery resources o f the
S c ie n c e , (D) 6(6):291 -5
Sella,
Sea tu rtle s in the eastern M editerranean and northern Red Sea. In K. Björndal (ed.): Biology and
conservation o f sea turtles. Proc. W orld Conf. Sea Turtle Conserv., W ash., D.C., 26-30 Nov. 1 979:417-23
I., 1981.
Sen aris,
C.,
1988.
S h o o p , C .R.,
&
En
peligro.
Philippine Islands.
Pro V ita A n im a liu m ,
Part IV. M iscellaneous m arine products. Journal o f
2(4): 10-2
C. Ruckdeschel, 1982. Increasing turtle strandings in the southeast United States:
factor. Biol. C o n se rv., 23:213-5
a com plicating
Silas, E.G ., M.
R ajagopalan & A. B astian-Fernando, 1983. Sea turtles o f
India. Need for a crash program m e on
conservation and effective m anagem ent o f the resource. Mar. Fish. Infor. Serv. Tech. and Extension
S e r., 50:1-23
Silas, E.G. e f a/.,
1985. On the large and mini arribadas o f the olive ridley Lepidochelys olivacea at Gahirm atha, Orissa
d u rin g the 1985 se a so n. M a r.F is h .Infor. Serv. Tech. and E xtension S e r., 64: 1-16
Sm all, V., 1982.
Sea turtle nesting at Virgin Islands National Park and Buck Island R eef National M onum ent 1980-81.
U.S. Dep. o f th e Int. N at. P ark. S e rv. R e se a rch Res. M a n a g e m e n t R ep.; S E R -6 1 , 54 pp.
S m ith ,
H .M .
S m ith ,
H .M .
& R. B. Sm ith, 1980.
Synopsis o f the herpetofauna
Johnson, North Bennington, Verm ont., 1044 p.
&
S pring, C.S.,
VI.
G uide to
M exican tu rtle s.
J.
E.H. Taylor, 1950. An annotated checklist and key to the reptiles o f Mexico exclusive o f the snakes.
B ull.U .S . Nat. M u s ., 199:1-253
1981. Status o f m arine turtle population in Papua New Guinea, in K. Björndal (ed.): Biology and
conservation o f sea turtles. Proc.W orld Conf. Sea Turtle Conserv., W ash..D.C.. 26-30 Nov. 1979:281-9
Stejneg er,
L.,
S te jn e g e r,
L.
S te rn b e rg ,
o f M exico.
1907.
Herpetology o f Japan and adjacent territory. Bull. U.S. Nat. M us., 58:577 p., 409 fig., 35 pit.
& T. B arbour, 1943. A checklist
C om p. Z o o l., 98(1 ):26 0 p.
J.,
o f North A m erican
am p h ib ia n s and
reptiles,
(5th
ed.).
1981. The worldw ide distribution o f sea turtle nesting beaches. Center for Environm ental
W ash. DC, 5 p., 6 m aps
Bull.
Mus.
Education,
, 1982. Sea turtle hunts throughout the world. C enter for Environm ental Education, Sea Turtle Rescue
Fund. W a sh .D C , 16 p.
Sutanto-Suw elo. I., N. Sum ertha-N uitja & I. Soetrisno. 1981. M arine turtles in Indonesia, in K. Björnal (ed.): Biology
and conservation o f sea turtles. Proc. W orld Conf. Sea T urtles Conserv., W ash., D-C., 26-30 Nov. 1979:
349-51
S u therlan d,
J.M .,
Uchida, I.,
1977.
Uchida.
1985.
M arine tu rtle s in G reece and th e ir co n se rva tio n .
Ocean navigation o f sea turtle.
M ar.T urtle
N e w s le tte r, 3 2:6-8
Bunken Publish Co., Osaka, Japan, 80 p. (in Japanese)
I. & M .N ish iw aki, 1981. Sea tu rtle s in the w a te rs ad ja ce nt to Japan. In K. Björndal (ed.): Biology and
conservation o f sea turtles. Proc.W orld Conf. Sea Turtle Conserv., W ash., D. C., 26-30 Nov. 1979: 317-9
74
Uchida,
S.
& H. T eruya, 1988. A) T ra n sp a cific m igration o f a tagged loggerhead, C aretta caretta. B) Tag-return
result o f loggerheads released from Okinawa Is., Japan. Okinawa Expo-Aquarium , 18 p. (ms)
Urlich, G.F. & A .S .Parkes, 1978. The green sea turtles (C helonia m ydas): further observations on breeding in captivity.
J. Zool. Lon do n , 1978(185):237-51
Van Denburgh, J., 1922. The reptiles o f w estern North Am erica. Vol. II. Snakes and turtles. O cc.Papers C alif.A cad.S ci.,
10:615-1028
Varona, S .L., 1974. Nuevo reporte de Lepidochelys olivacea (Testudinata: C heloniidae) de Cuba. Poeyana. 137:4 p.
Veniselos, L. E., 1986. G uest editorial: G reek loggerheads face dangers. M ar.Turtle N ew sletter, 39: 10-1
W erm uth, H. & R. M ertens, 1961. Schildkröten, Krokodile, Brückenechsen. VeB Gustav Fischer Verlag, Jena, 422 p.
W hitm ore, C .P. & P.FI. Dutton, 1985. Infertility, em bryonic m ortality and nest-site selection
sea tu rtle s in Surinam e. B io l.C o n se rv., 34(1985): 251-72
in leatherback and green
W ickram singe, R.S.B., 1982. Turtle hatcheries in Sri Lanka. M ar.Turtle N ew sletter, 22:3-4
W illiam s, E.E., A.C. G randison & A. Carr, 1967. C helonia depressa Garman re-investigated. Breviora, M us.Com p.Zool.,
Harvard U niv., 271: 15 p.
W itham , R., 1974. Neonate sea turtles from the stom ach o f a pelagic fish. C o p e ia ,
W itzeil,
W .N ., 1980. G rowth o f captive
S cie n ce , 30(4):909-12
haw ksbill
W itzeil,
W .N ., & A .C . Banner, 1980. The
S cie n ce , 30(3):571-579
tu rtle s
E retm och elys
haw ksbill turtle
1974(2):548
im b ricata,
Eretm och elys im b ricata,
in
w estern Sam oa.
Bull.M arine
in w estern Sam oa.
Bull.M arine
W ood, J.R., F.E. W odd, & K. Critchley, 1983. Hybridization o f C helonia m ydas and Eretm ochelys im bricata. Copeia.
(3):839-42
Yáñez,
Zan gerl,
Zug,
A .,P .,
R.,
1951.
L.P.
G .R., A .H .
Vertebrados
m arinos
chilenos.
Rev.
Biol.
H end rickson & J.R. H end rickson , 1988. A redescription o f the
N a ta to r d e p re s s u s . B ish o p M u s .B u ll.Z o o l.I., H o n o lu lu . 69 p.
W ynn
& C.
R uckdeschel,
1986. Age
determ ination
increm ental grow th m arks in the skeleton.
Z w eifel,
M ar.(V a lp a ra iso ), 3 (1 ,2):1 -18
o f loggerhead
fla tb ack
sea turtle, C aretta
sea
turtle
caretta, by
S m ithsonian C o n tr.Z o o lo g y. 427: 1-34
R.G., 1960.
R esults o f the puritan-am erican m useum o f natural
A m erican M useum o f N atural H istory B u ll., 119(2):94
Zw inenberg, A .J.,
A u stra lia n
history
1976. The olive rid le y, L ep ido chelys olivacea (Eschscholtz,
m arine turtle today. Bull.M aryland H e rp.S o c., 1 2 (3 ):75-95
expedition
1829):
to
probably the
w estern
M exico.
m ost num erous
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75
5.
INDEX OF SCIENTIFIC AND VERNACULAR NAMES
EXPLANATION OF THE SYSTEM
The index applies exclusively to family and species accounts (Sections
2.2 and 2.3)
Type faces
used:
Italics
: Valid scientific names (double entryby genera and species)
Italics
: Primary synonyms (double entry bygenera and species)
Roman
: International (FAO) species names
Roman
: Local species names
ROMAN
: Families
76
A
A b u g u d r ..........................................................................
agassizii, C h e lo n ia ......................................................
A h u la m ..............................................................................
A itk a n ti ..............................................................................
A ka um i gam e ................................................................
albiventer, Chelone........................................................
A lungam ai ..........................................................................
A lu n k a m a i........................................................................
angusta, S p h a rg is ..........................................................
Ao u m i-g a m e ....................................................................
A o n a n a ..............................................................................
A p u h u lu ..............................................................................
A p u h u r u ..............................................................................
A r a u a n a ..............................................................................
a rc u a ta ,T e s tu d o ..............................................................
A ru a n a ................................................................................
A sa ......................................................................................
A s s a ......................................................................................
A tla n tic rid le y tu rtle ........................................................
atlantica, D erm o ch elis..................................................
atra, C a re tta ......................................................................
A vo de a ru a n a ..................................................................
A y ik p lo to ..............................................................................
38
21
48
58
20
25
37
38
53
30
48
30
37
30
53
30
30
30
42
53
14
20
37
B
B a - T a m ................................................................................. 58
B a b a m u k a r a ........................................................................20
B a g a ........................................................................................37
B a g e ........................................................................................48
B a sta rd t u r t le .................................................................... 42
Batu c a s b a w ........................................................................ 48
B a u la ...................................................................................... 58
B a u le ...................................................................................... 58
B e s t’ia .....................................................................................48
bicarinata, C h e lo n ia .........................................................25
B is s a .......................................................................................37
bissa, C a re tta ......................................................................31
B la c k tu r tle ........................................................................... 25
B o b a ........................................................................................20
B o lu ........................................................................................58
B o s a n g e ............................................................................... 58
B u fe a d o ra ............................................................................. 58
B u n g ....................................................................................... 48
C
C a g u a m a .......................................................................... 14
C a g u a m a ............................................................................ 20
C a g u a m a p r ie ta .............................................................. 25
C a h u a m a ......................................................................... 2 0 ,48
C a la p ....................................................................................... 30
C a n a l.................................................................................... 58
C a n a s tra ............................................................................ 58
Caouana
..................................................................... 1 3 ,3 8
Caouana e lo n g a ta ............................................................ 14
Caouana R u p p e llii.......................................................... 43
Caouana, T es tu d o .......................................................... 14
C a rd o n .................................................................................. 20
C a r e m b o l............................................................................ 58
C a re p a b e c e rra .................................................................. 58
C a r e t ............................................................................ 3 7 ,38
C a r e tta .............................................................................. 13
C aretta ............................................................................ 30
Caretta a tr a a .................................................................. 14
C afetta b is s a .................................................................. 31
c a re tta , C a r e t t a ............................................................ 14
C a re tta c a re tta ............................................................ 14
C aretta caretta ta r a p a c a n a .................................... 14
C a re tta C e p e d ii.............................................................. 25
C a re tta C e p h a lo ............................................................ 14
C a retta e s c u le n ta .......................................................... 25
C a re tta g ig a s .................................................................. 14
C a re tta n a s ic o rn is ........................................................ 25
C a re tta n a s u ta .............................................................. 14
Caretta rem ivaga.............................................................. 43
Caretta s q u a m o s a ........................................................ 31
Caretta tarapacana, C a re tta .................................... 14
Caretta, te s tu d o ............................................................ 25
Caretta Thunbefgii ...................................................... 25
C a r e y .................................................................................. 37
C a r p in te r a ........................................................................ 48
carri negra, Chelonia m y d a s ...................................... 21
cavana, C h e lo n ia .......................................................... 14
Cepediana, T e s tu d o .................................................... 25
Cepedii, C a r e t t a ............................................................ 25
Cephalo, C a retta............................................................ 14
Cephalo, Testudo ........................................................ 14
C ephalochelys .............................................................. 13
C ephalochelys oceanica .......................................... 43
C h a lu p a ............................................................................ 58
C h a lu p a sie te f ilo s ........................................................ 58
C h e lo n a ............................................................................ 21
C h e lo n e ..........................................................................21 ,49
Chelone a lb iv e n te r ...................................................... 25
C h e lo n ia .......................................................................... 21
Chelonia .............................................................. 2 1 ,4 9 ,5 3
C h e lo n ia a g a s s i z i i .................................................... 21
Chelonia b ic a rin a ta ...................................................... 25
Chelonia c a v a n a ............................................................ 14
Chelonia d e p re s s a ........................................................ 49
Chelonia d u b ia ................................................................ 43
Chelonia (Euchelonia) m id a s .................................... 21
Chelonia esculenta ...................................................... 25
Chelonia fo r m o s a .......................................................... 25
Chelonia ja p o n ic a ....................................................... 21 ,49
Chelonia la c h r y m a ta .................................................... 25
Chelonia lata .................................................................. 21
Chelonia lutaria ............................................................ 53
Chelonia L y r a .................................................................. 53
Chelonia m a c u lo s a ........................................................ 25
Chelonia m a rm o ra ta ...................................................... 25
Chelonia m u ltic u s ta ta .................................................... 43
C h e lo n ia m y d a s ............................................................ 25
Chelonia mydas c a rrin e g ra ........................................ 21
Chelonia olivacea .......................................................... 43
Cheonia p e la s g o ru m .................................................... 14
Chelonia polyaspis ...................................................... 43
Chelonia p s e u d o -c a re tta ............................................ 31
Chelonia pseudo-m idas ............................................ 31
Chelonia s u b c a rin a ta .................................................... 43
Chelonia te n u is ................................................................ 25
Chelonia V ir g a ta ..........................................................21 ,25
Chelonia v irid is ................................................................ 21
C h e lo n ia s ............................................................................ 21
77
C H E L O N IID A E ................................................................
C h ely ra ..............................................................................
chloronotus, Testudo ..................................................
C oco ....................................................................................
Colpochelys ......................................................................
Con d o i-m o i ......................................................................
C o n d it ..................................................................................
controversa, Thalassochelys ....................................
c o ria c e a , D e r m o c h e ly s ..............................................
coriacea Schlegelii, S p h a rg is ....................................
coriacea, Testudo............................................................
coriaceous, T e s tu d o ......................................................
Corianna, T e s tu d o ..........................................................
C o riu d o ................................................................................
corticata, T h a la s s o c h e ly s ............................................
13
53
25
20
38
38
48
43
53
53
53
53
14
53
14
D
D a ra u .................................................................................... 38
depressa, C h e lo n ia ........................................................ 49
d e p re s s u s , N a t a t o r ...................................................... 49
D e rm a to c h e lis .................................................................... 53
D erm atochelys ................................................................ 53
D erm atochelys p o r c a ta ................................................ 53
D e rm o c h e lis ........................................................................ 53
D erm ochelis a tla n tic a .................................................... 53
D E R M O C H E L Y ID A E ........................................................ 53
D e rm o c h e ly s .................................................................. 53
D e rm o c h e ly s c o r ia c e a .................................................. 53
De s o p a ................................................................................ 30
D hara k a s lo a v e ..................................................................58
D honi a m a i ........................................................................ 58
D h o n i-a m a i ........................................................................ 58
D o i- m o i................................................................................ 58
dubia, C h e lo n ia ..................................................................43
D u c h -k a c c h u a .................................................................... 30
dussumieri, L e p id o c h e ly s............................................ 43
E
E a .......................................................................................... 37
East P a c ific g re e n t u r t le ................................................ 25
E a ste rn P a c ific g re e n tu r tle .......................................... 21
Echte K a r e tts c h ild k r ö te .................................................. 37
elongata, C aouana .......................................................... 14
e lo n g a ta , T h a la s s o c h e ly s ............................................ 14
E lu v a r a i-a m a i.................................................................... 58
E luvi ........................................................................................ 20
E p a p o .................................................................................... 58
E r a .......................................................................................... 38
Erem onia.............................................................................. 13
E r e tm o c h e ly s .................................................................. 30
E re tm o c h e ly s im b ric a ta .............................................. 31
Eretm ochelys s q u a m a ta ..................................................31
esculenta, Caretta .......................................................... 25
esculenta, Chelonia ......................................................
Euchelonia ........................................................................
Euchelys ............................................................................
Euchelys m a c ro p u s ........................................................
E w e - k lo ................................................................................
25
21
21
25
30
Fano ....................................................................................
F a n o h a ra ............................................................................
F i a t b a c k t u r t l e ................................................................
F ia tb a ck t u r t le ..................................................................
F o a k o n a ..............................................................................
30
38
49
52
58
Fonu ko lo a .......................................................................... 38
formosa, C h e lo n ia .......................................................... 25
F u n g ...................................................................................... 38
G
G a -h a la .............................................................................. 30
G a d ha k a cch u a ................................................................ 48
G al ka sb a va ...................................................................... 30
G a la p a g o ............................................................................ 58
G aula .................................................................................. 58
G e la ...................................................................................... 38
gigas, Caretta .................................................................... 14
G o lfin a .................................................................................. 48
G oli ...................................................................................... 58
G o u n a m .............................................................................. 37
G r e e n s e a t u r t l e ............................................................ 25
G reen tu rtle ........................................................................30
G ro e n s e e s k ilp a d .............................................................. 30
G rosse t ê t e ..........................................................................20
G uan d o n g ............................................................................48
G u ig u in a .............................................................................. 20
G u ilto ra .............................................................................. 25
H
H a la p a ta d z i ........................................................................37
H a i i chelys ............................................................................ 13
H a r a ........................................................................................ 38
H a w k’s b i l l ............................................................................38
H a w k b ill..................................................................................38
H a w ksb ill ..............................................................................38
H a w k s b i l l s e a t u r t l e .................................................... 31
H a w ksb ill tu rtle ..................................................................37
Herpysm ostes ....................................................................30
H im e -u m ig a n e ....................................................................48
Honu ......................................................................................30
I
Icaha .................................................................................... 30
Ifudu .................................................................................... 30
Ika d a m e ................................................................................30
Ik a -ta ’o n e ............................................................................ 30
llo n g o s i................................................................................ 20
Im b rica ta ............................................................................ 38
im bricata, Eretm ochelys................................................ 31
im bricata, T estu d o ..........................................................
In g a p p a ................................................................................
I n h a m a ................................................................................
Inhasa ................................................................................
Irun d u ................................................................................
Itaruca ................................................................................
31
38
38
58
58
30
J
F
F a h ro u n el b a h r ..................................................................20
ja c o n a .................................................................................. 30
japonica, Chelonia ........................................................ 49
japonica, Testudo .......................................................... 25
78
J a v a lin a .............................................................................. 20
J e b a k e .................................................................................. 38
K
Kadaloe .............................................................................. 30
K a la -lu w a .......................................................................... 37
K a ngha ka c -c h u a .......................................................... 38
K a r’et ..................................................................................
K assa ..................................................................................
K a w a -n a ............................................................................
K aw ana ..............................................................................
K e m p 's r id le y t u r t le ....................................................
K e m p ’s rid le y tu rtle ......................................................
k e m p ii, L e p id o c h e ly s ..................................................
kempii, T h a la s s o c h e ly s ................................................
38
30
58
58
39
42
38
38
Kertseeskipad .................................................................... 20
Kikila ...................................................................................... 52
K o p e m ................................................................................ 58
pi ................................................................................
37
K ra p ’e ..................................................................................
Kraussr, O nychochelys....................................................
Krayoea ..............................................................................
Kuaurai ................................................................................
Kula-lasi ..............................................................................
K u la la sh i ............................................................................
Kulalashli ............................................................................
Kou
30
31
37
58
48
48
37
L
L a b i-la b i.............................................................................. 58
lachrymata, Chelonia .................................................... 25
Lantuc ................................................................................ 20
Lappi .................................................................................. 38
lata, Chelonia .................................................................. 21
Latuk
............................................................................ 58
Laúd .................................................................................... 58
Leatherback ........................................................................ 58
L e a th e rb a c k t u r t le ............................................................ 53
L e a th e rtru n k tu rtle ........................................................ 58
Leathery .............................................................................. 58
Lederschildkröte
............................................................ 58
Lederschilpad .................................................................... 58
Leerrugseeskilpad.............................................................. 58
Lem ech ..................................................................... 20,30,48
Leng-Pi-G ui ........................................................................ 58
L e p id o c h e ly s .................................................................... 38
Lepidochelys dussum ieri................................................ 43
L ep ido chelys k e m p ii .................................................... 38
L ep ido chelys o liv a c e a .................................................. 43
L ic o te a .................................................................................. 58
L in d i...................................................................................... 20
L o b a ...................................................................................... 48
L o g g e rh e a d ...................................................................... 20
L o g g e rh e a d tu rtle .......................................................... 14
Lora ...................................................................................... 48
lutaria, C h e lo n ia .............................................................. 53
L u th ........................................................................................ 58
Lyra, C h e lo n ia .................................................................. 53
lyra, Testudo........................................................................ 53
M
M abua ............................................................................ 48,58
M a c h in c u e p o ................................................................ 58
macropus, Euchelys .................................................... 25
macropus, Testudo ...................................................... 25
maculosa, Chelonia ...................................................... 25
Mada casbaw .................................................................... 48
Mahana .............................................................................. 38
Maia .................................................................................... 38
M a iw a .................................................................................. 20
M a iw a -g a m o .................................................................... 20
M a k a b n i.............................................................................. 48
M ako l o a ............................................................................ 30
M ali ka sb a va .................................................................... 30
M a n ib u ................................................................................ 58
M arab ................................................................................ 20
marina, T e s tu d o .............................................................. 53
M arina Vulgaris, T e s tu d o ............................................ 25
M arm orata, Chelonia .................................................. 25
M as ka sb a va .................................................................... 30
M a ta -m a ta ........................................................................ 58
M e g e m y s ..............................................................................21
M elop .................................................................................. 30
mercurialis, S p h a r g is .................................................... 53
midas, Chelonia (E u c h e lo n ia )...................................... 21
midas, Testudo ................................................................ 53
minor, Testudo mydas ..................................................43
M ira n g ..................................................................................58
M o g o b u l................................................................................20
M oka b u .............................................................................. 48
M o rro co y .......................................................................... 38
Mu w in ic h e n ...................................................................... 38
m ulticustata, C h e lo n ia .................................................. 43
M u s a n a .................................................................................. 38
M y d a s .................................................................................... 21
mydas carrinegra, Chelonia ...................................... 21
m y d a s , C h e lo n ia .......................................................... 25
m ydas minor, T e s tu d o .................................................... 43
mydas, Testudo .............................................................. 25
N
N d u v i.................................................................................... 20
N a ’ama ................................................................................ 58
N a im a i ................................................................................ 20
Nam koyo .......................................................................... 20
n a s ic o rn is , C a re tta ........................................................ 25
n a s ic o rn is , T e s tu d o ........................................................ 14
n a su ta , C a re tta ................................................................ 14
N a ta to r ....................................................................................49
N a ta to r d e p re s s u s ............................................................49
N a ta to r te s e lla tu s
..........................................................49
N a y a m b a .............................................................................. 37
N g a se ch .............................................................................. 38
N o a ..........................................................................................58
N r u b ...................................................................................... 30
N ukali .................................................................................. 20
N yam ba ............................................................................ 30,37
N zim a -a n ju a ...................................................................... 30
79
O
R
oceanica, C ephalochely ............................................
O lifk e u rig e R id le y ........................................................
olivacea, Chelonia ........................................................
o liv a c e a . L e p id o c h e ly s ..............................................
O live rid le y ......................................................................
O liv e r id le y t u r t l e ........................................................
O lo lo ....................................................................................
Olu g e d d i k a s d a v a ........................................................
O n y c h o c h ely s ..................................................................
O nychochelys kraussi ................................................
O p a pe i ................................................................................
Osa g a m e ..........................................................................
O ulo ....................................................................................
O u z o ....................................................................................
43
48
43
43
48
43
38
20
30
31
38
58
48
48
P
Pacific rid le y ...................................................................... 48
Palam ai .............................................................................. 30
P a ra p e .................................................................................. 38
P a rla m a ............................................................................. 25,48
P a sla m a ................................................................................ 48
P a w ic a n ................................................................................ 58
Paw ikan .....................................................................20,30,38
p e la s g o ru m , Chelonia .............................................. 14
Peleleu ................................................................................ 58
P e n y u .................................................................................... 30
Penyu a g a r ...................................................................... 30
Penyu a lg u -a b u .............................................................. 48
Penyu b e lim b in g ............................................................ 58
P enyu d a g in g .................................................................. 30
P e n y u k a ra h ........................................................................ 38
P e n y u lip a s .......................................................................... 48
Penyu m angong
.......................................................... 20
Penyu nijaul ...................................................................... 30
Penyu pulau ...................................................................... 30
Penyusale
...................................................................... 30
P e n y u s is e k .......................................................................... 38
Penyu s is ik .......................................................................... 38
Penyu waukaku .............................................................. 20
P e ra m a i................................................................................ 30
Perica .................................................................................. 20
P e rra m a i ............................................................................ 30
Perunthalai amai ............................................................ 20
Pica de lo r o ........................................................................ 48
P im b a t ................................................................................ 48
polyaspis, C h elo n ia........................................................ 43
P o n o w a n ............................................................................ 20
porcata, Derm atochelys.................................................. 53
P otu ka sva b a .................................................................... 38
P ow ikan .............................................................................. 48
pseudo-caretta, Chelonia ............................................ 31
pseudo-midas, Chelonia .............................................. 31
Purai .................................................................................... 38
P w iri .................................................................................... 57
Q
Q uan d ong
........................................................................ 48
rem ivaga, C a re tta ..........................................................
R e m a n i ............................................................................
R o n t o ................................................................................
rugosa, Testudo ............................................................
Ruppellii, C aouana ......................................................
43
20
58
25
43
S
S a c a c illo ............................................................................ 25
S a g l...................................................................................... 37
S a m u d ric k -k a s im ............................................................ 48
S a m u d rik kasim ........................................................... 37,58
S a p a k e ................................................................................ 38
S at k r a s .............................................................................. 38
Schlegelii, Sphargis coriacea ................................ 53
Scytena .............................................................................. 53
Scytina .............................................................................. 53
S c y tin e ................................................................................ 53
S e e s k ilp a d ........................................................................ 48
Seytina .............................................................................. 53
Seytinia ............................................................................ 53
S fa rg id e ............................................................................ 58
S h e r-c a c c h u a .................................................................. 58
S h ita m a i ............................................................................ 48
S h u ke rt .............................................................................. 38
S ib irro ................................................................................ 48
S ik s ik a n ti .......................................................................... 58
S ip h a rg is ............................................................................ 53
S isika n ................................................................................ 38
S isila p a g al ...................................................................... 38
S is ip a n g a l ........................................................................ 38
Sphargis ............................................................................ 53
Sphargis angusta .......................................................... 53
Sphargis coriacea Schlegelii .................................. 53
Sphargis m e rc u ria lis ...................................................... 53
Sphragis ............................................................................ 53
squam ata, Eretm ochelys .......................................... 31
sq u am o sa,C aretta ........................................................ 31
subcarinata, C h e lo n ia ................................................ 43
S u g r ................................................................................ 37,38
S u p p e n s c h ild k rö te .......................................................... 30
S u r u a n a .............................................................................. 30
T
T aha .................................................................................... 38
T ai m ei .............................................................................. 37
T a i- m a i................................................................................ 38
T aku .................................................................................... 37
T a o -kra .............................................................................. 38
T a o -M a -F u e u n g .............................................................. 58
T a o -ta -n u .......................................................................... 30
T ao -ya ............................................................................ 20,48
tara p acan a,C aretta caretta ...................................... 14
tarapacana T h a la s s o c h e ly s ...................................... 43
tarapacana T h a la s sio c h e ly s...................................... 43
T a ra s al a s f a r .................................................................. 20
T a rta ru g a .......................................................20,30,38,48,58
T a rta ru g a b a s t a r d a ......................................................42,48
T a rta ru g a c a r e t .............................................................. 20
80
T a rta ru g a
T a rta ru g a
T a rta ru g a
T a rta ru g a
T a rta ru g a
T a rta ru g a
T a rta ru g a
c a re tta .......................................................... 20
c o m u n e ........................................................ 20
de c o u ro t .................................................... 58
de luth .......................................................... 58
de p e n te ................................................... 37,38
fra n c a ............................................................ 30
g ra n d e e n c o u r a d a .................................... 58
T a rta ru g a im b ric a d a ...................................................... 37
T a rta ru g a liu to ................................................................ 58
T a rta ru g a m e s tic o n a .................................................... 20
T a rta ru g a v e rd a d e ira .................................................. 37
T a rta ru g a v e rd e ............................................................ 30
T a u -d a ................................................................................ 38
tenuis, C h e lo n ia .............................................................. 25
T e ra -k u i .............................................................................. 48
tessellatus, N a tato r .................................................... 49
Testudo .............................................................................. 53
Testudo arcuata ............................................................ 53
Testudo C aouana .......................................................... 14
Testudo caretta .............................................................. 14
Testudo cepediana ........................................................ 25
Testudo Cephalo ............................................................ 14
Testudo chloronotus .................................................... 25
Testudo c o r ia c e a ..............................................................53
Testudo c oriaceo us........................................................ 53
Testudo Corianna .......................................................... 14
Testudo im bricata ........................................................ 31
Testudo japo nica .............................................................. 25
Testudo l y r a ...................................................................... 53
Testudo m a c ro p u s .......................................................... 25
Testudo m arina .............................................................. 53
Testudo M arina Vulgaris ............................................ 25
Testudo m id a s ..................................................................
Testudo mydas ..............................................................
Testudo m ydas m inor ..................................................
Testudo n a s ic o rn is ........................................................
Testudo rugosa ..............................................................
Testudo tuberculata ......................................................
Testudo viridi-squam osa ............................................
Testudo viridis ................................................................
Thalassiochelys ta ra p a c o n a ......................................
Thalassochelys ..............................................................
Thalassochelys controversa ....................................
Thalassochelys corticata ..........................................
Thalassochelys e lo n g a ta ............................................
Thalassochelys k e m p ii................................................
Thalassochelys ta ra p a c a n a ........................................
T h o n i-a m a i ........................................................................
Thunbergii, C aretta ......................................................
T im b a u ................................................................................
T in g la d a ............................................................................
T in g la d o ..............................................................................
T in g la r ..................................................................................
T in u k ..................................................................................
T o n e s u ................................................................................
T on g o t o n g o ......................................................................
T o r a ......................................................................................
53
25
43
14
25
53
25
25
43
13
43
14
14
38
43
58
25
30
58
58
58
58
58
30
58
T o rita ..................................................................................
T o r t i......................................................................................
T o rti b a t a r ..........................................................................
T o rti ka ra m b o l ................................................................
T o r to is e -s h e ll....................................................................
T o rtu e à é c a i llé s ............................................................
25
30
20
58
38
38
T o rtu e
T o rtu e
T o r tu e
T o r tu e
T o rtu e
b â ta r d e ............................................................. 42,48
ca o u a n n e .......................................................... 20
c a o u a n n e .......................................................... 14
c a r e t .................................................................... 31
d ’e c a ille .............................................................. 37
T o rtu e de c u ir ................................................................ 58
T o r tu e de K e m p ............................................................ 38
T o rtu e de K e m ..............................................................42,48
T o rtu e de R id le y ......................................................... 42,48
T o rtu e de r o c h e s ............................................................ 48
T o rtu e f r a n c h e ................................................................ 30
T o rtu e im b riq u é e .......................................................... 37
T o rtu e ja u n e .................................................................... 20
T o r tu e l u t h ...................................................................... 53
T o rtu e l u t h ........................................................................ 58
T o rtu e m a n g e a b le .......................................................... 30
T o r tu e o l i v â t r e .............................................................. 43
T o rtu e o liv â tre .............................................................. 48
T o rtu e o liv e ........................................................................ 48
T o r tu e p l a t t e .................................................................. 49
T o rtu e t u ille ...................................................................... 38
T o r tu e v e rd e .................................................................. 25
T o rtu e v e r t e ...................................................................... 30
T o r tu e v e rte d u P a c ifiq u e e s t .............................. 21
T o rtu g a b a s ta r d a ..........................................................42,48
T o r tu g a b la n c a ............................................................ 26
T o rtu g a b la n ca ............................................................25,30
T o rtu g a c o m e s tib le ...................................................... 25
T o rtu g a c o to rra .............................................................. 42
T o rtu g a de c a n a l............................................................ 58
T o r tu g a de c a re y ........................................................ 31
T o rtu g a de c u e r o .......................................................... 58
T o rtu g a de K e m p .......................................................... 48
T o rtu g a f in a ...................................................................... 37
T o rtu g a f r a n c a ................................................................ 30
T o rtu g a g ogo .................................................................. 20
T o r tu g a g o lfin a ............................................................ 43
T o r tu g a la ú d ................................................................ 53
T o rtu g a laúd .................................................................... 58
T o r tu g a l o r a .................................................................... 38
T o rtu g a lora .................................................................... 42
T o rtu g a m an ila .............................................................. 48
T o rtu g a m ulato ............................................................ 48
T o rtu g a n e g r a .................................................................. 25
T o r tu g a p la n a de A u s t r a l i a .................................... 49
T o r tu g a p r i e t a ................................................................ 21
T o rtu g a p rie ta ................................................................ 25
T o rtu g a sie te f i l o s ........................................................ 58
T o rtu g a v e rd e .......................................................... 25,30
T o tto n g a n .......................................................................... 38
T re s q u illa s .................................................................... 58
T r u n k .................................................................................. 58
T s u - t s i................................................................................ 20
T u ’a ’u l i ................................................................................ 30
T u ’a p o la ta ........................................................................ 30
T u a n g a n g e ...................................................................... 48
tuberculata, Testudo .................................................. 53
T u fo n u ................................................................................ 30
u
U naw a ........................................................................ 37,38
U n e ch te K a r e tts c h ild k r ö te ........................................ 20
81
U n u w a ........................................................................................ 37
U ruana ...................................................................................... 30
Usi v i d i ...................................................................................... 52
V
V a lk b e k s e e s k ilp a d .............................................................. 38
V a lo z o ro .................................................................................. 58
Veu ...................................................................................... 38,58
V ich ............................................................................................ 30
virgata C h e lo n ia ............................................................ 21,25
viridi-squamosa, Testudo ................................................
viridis, C h e lo n ia ....................................................................
viridis, T e s tu d o ........................................................................
V o n u d a m u ..............................................................................
Vo n u lo a ..................................................................................
V ovo de t a r t a r u g a ................................................................
Vulgaris, Testudo M arina ................................................
25
21
25
30
30
20
25
w
W a ra n a .................................................................................... 48
W au m is .................................................................................. 38
W e d a ra .................................................................................... 58
W e t m won ............................................................................ 30
W h ite tu rtle
.......................................................................... 30
W in im o n .................................................................................. 30
W o n ............................................................................................ 30
W o n e ra .................................................................................... 58
W o n g e ra .................................................................................. 58
W ounlele ................................................................................ 38
X
X ic o v e ......................................................................................
48
Y
Y a d i-d a
30