Iff..
THE POPULATION STRUCTURE & DISTRIBUTION OF SAND DOLLAR ACROSS INTERTIDAL ZONE AT PAN DAN BEACH, LUNDU AND TROMBOL, TELAGAAIR SARAWAK Intan Rohayu Binti Sukimin
(30437)
QL
384
E2
161
2014
Bachelor of Science with Honours
(Aquatic Resource Science and Management)
2014
The Population Structure & Distribution of Sand Dollar across Intertidal Zone at Pandan
Beach, Lundu and Trombol, Telaga Air Sarawak.
Intan Rohayu binti Sukimin (30437)
A report submitted in partial fulfilment of the Final Year Project 2 (STF 3015)
Supervisor: Dr. Siti Akmar Khadijah bt Ab. Rahim
Aquatic Resource Science and Management Programme
Department of Aquatic Science
Faculty of Resource Science and Technology
Universiti Malaysia Sarawak
20 June 2014
Table of Contents
Contents
Page
Table of Contents
i
List of Abbreviation
ii
List of Table and Figure
iii
1. Introduction
1
2. Literature Review
3
2.1
Introduction to sand dollar
3
2.2
Classification of sand dollar
3
2.3
Aggregation and patchiness of sand dollar
4
2.4
Sediment preference of sand dollar
5
2.5
Feeding, burrowing and locomotion behaviour of sand
dollar
6
2.6
Feeding mechanism
6
2.7
Food preference
7
3. Materials and Methods
8
3.1
Description of study sites
8
3.2
Sampling and data collection
9
3.3 Morphometric measurement and identification of sand
dollar
11
3.4
Sediment grain size analysis
11
3.5
Data analysis
11
3.6
Statistical analysis
11
4. Current Status
12
4.1
Species Identification of Sand Dollar
13
4.2
Number of sand Dollar
14
4.3
Population Structure
17
4.4
Species Composition
21
5. References
22
Acknowledgments
Firstly, I want to express my gratitude to Allah for his blessings throughout the duration of my
research and completion of this project. Special thanks to Dr. Siti Akmar Khadijah bt Ab. Rahim
as my Supervisor and Mentor who had given me constant guide, advice, wisdom and expertise.
Your patience and hard work are really appreciated. Not to forget my examiner Dr Samsur
Mohamad, thank you for your comments to improve my project.
Secondly, I would like to thank my parents, Mr Sukimin bin Selamat and Mdm Masitah binti
Abdul Samad for all the supports and beliefs .Thank to my friends especially to Noramira binti
Mohd Amin, Nurshuhada binti Mohd Aris and Ahmad Syahir Alias for helping me during
sampling and lab works.
Special thanks to the lab assistant Mr Richard Toh for spending time in helping me throughout the
project, thanks also to postgraduate students Norhakimi Muhamad and Raymie Nurhasan for all
the guidelines and advices through my analysis and projects. To other lecturers and staffs of
Aquatic Department thanks for your time helping me completing this project. Thank you so much
you guys, I could not have done it without you.
I
2014
DECLARATION
I hereby declare that the work in this project is my own except for quotations and summaries
which have been duly acknowledged. No portion of the work referred to in this dissertation has
been submitted in support of an application for another degree qualification of this or any other
university or institution of higher learning.
………………………………..
Intan Rohayu binti Sukimin
Aquatic Resource Science and Management
Department of Aquatic Science
Faculty of Resources Science and Technology
Universiti Malaysia Sarawak
II
Table of Contents
Content
Acknowledgement
Declaration
Table of contents
List of figures
List of tables
List of abbreviations
Abstract
1.0 Introduction
2.0 Literature Reviews
2.1Introduction to sand dollar
2.2 Classification of sand dollar
2.3 Aggregation and patchiness of sand dollar
2.4 Sediment particle size preferred by sand dollar
2.5 Feeding, burrowing and locomotion behaviour of sand
dollar
2.6 Feeding mechanism
2.7 Food preference
3.0 Materials and Methods
3.1 Description of study site
3.2 Sampling and sand dollar collection
3.3 Morphometric measurement and identification of sand
dollar
3.4 Sediment grain size analysis
3.5 Data and statistical analysis
4.0 Results
4.1 Morphology characteristics of sand dollar
4.1.1 Description of Arachnoides placenta
4.1.2 Description of Echinodiscus tenuissimus
4.2 Population size structure
4.2.1 Population size frequency
4.2.2 Population size frequency distribution
4.3 Population density distribution
4.3.1 Mean density against distance
4.3.2 Comparing density between Lundu and Trombol
4.4 Comparing pore water parameters between Lundu and
Trombol
4.5 Sand fraction at Trombol and Lundu
4.6 Correlation
4.6.1 Correlation on pore water parameters with density
5.0 Discussion
5.1 Species composition
5.2 Population size frequency distribution
5.3 Population density of sand dollar
5.4 Pore water parameters
III
Page number
I
II
III
V
VII
VIII
1
2
4
4
4
6
7
7
8
9
10
10
11
13
14
14
15
15
16
17
18
18
21
24
24
27
29
32
35
36
40
40
40
41
42
6.0 Conclusion
43
7.0 References
8.0 Appendices
44
46
IV
List of Figures
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Figure 22
The morphological structure of sand dollar
Locations of study sites.
Illustration of three line transects across intertidal
zone from high tide to low tide.
Irregular sea urchin: Diagramatic plan of a
Clypeasteroid (sand dollar)
Numbers of Arachnoides placenta and
Echinodiscus tenuiismus present at Lundu and
Trombol.
Morphology of Arachnoides placenta
Morphology of Echinodiscus tenuissimus
Population size frequencies of adult sand dollars at
Lundu
Population size frequencies of Juvenile sand dollars
at Lundu
Population size frequencies of adult sand dollars at
Trombol
Population size frequencies of juvenile sand dollars
at Trombol
The mean test diameter (mm) versus distance
downshore (m) at Lundu of juvenile sand dollars.
The mean test diameter (mm) versus distance
downshore (m) at Lundu of adult sand dollars.
The mean test diameter (mm) versus distance
downshore (m) at Trombol of juvenile sand dollars.
The mean test diameter (mm) versus distance
downshore (m) at Trombol of adult sand dollars.
Mean density (individuals/m²) of test diameter <10
mm across intertidal zone at Trombol on October
2013.
Mean density (individuals/m²) of test diameter >10
mm across intertidal zone at Trombol on October
2013.
Mean density (individuals/m²) of test diameter <10
mm across intertidal zone at Lundu on January
2014
Mean density (individuals/m²) of test diameter >10
mm across intertidal zone at Lundu on January
2014.
Mean density of adult sand dollars at Lundu and
Trombol at three different zones
Mean density of juvenile sand dollars at Lundu and
Trombol at three different zones
Mean salinity at Lundu and Trombol in the three
different zones
V
8
10
12
13
15
16
17
19
19
20
20
22
22
23
23
25
25
26
26
28
28
29
Figure 23
Figure 24
Figure 25
Figure 26
Mean temperature at Lundu and Trombol in the
three different
Mean pH at Lundu and Trombol in the three
different
Zones
Sediment fraction percentage across intertidal
zones at Lundu.
Sediment fraction percentage across intertidal
zones at Trombol.
VI
30
31
33
34
List of Tables
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
Table 9
Table 10
Table 11
Key to major taxa of Arachnoides placenta and
Echinodiscus tenuissimus.
Linear regression analysis of the effect of distance
from the high tide on juvenile and adult sand dollars
at Lundu and Trombol.
Relationship between parameters with density of
adult and juvenile sand dollars using Pearson
Correlation analysis.
Correlation between pore water quality and density of
adult sand dollar at Lundu
Correlation between pore water quality and density of
juvenile sand dollar at Lundu
Correlation between pore water quality and density of
adult sand dollar at Trombol.
Correlation between pore water quality and density of
juvenile sand dollar at Trombol.
Density of adult sand dollar at Lundu and Trombol.
Density of juvenile sand dollar at Lundu and
Trombol.
Reading of pore water parameter at Lundu
Reading of pore water parameter at Trombol
VII
13
22
35
36
37
38
39
46
46
46
46
List of Abbreviations
ANOVA
-
Analysis of Variance
cm
-
Centimetre
GPS
-
Global Positioning System
m
-
Metre
μm
-
Micrometre
mm
-
Millimetre
n
-
Number of individuals
SPSS
-
Statistical Package for Social Science
VIII
THE POPULATION STRUCTURE AND DISTRIBUTION OF SAND DOLLAR AT
PANDAN BEACH, LUNDU AND TROMBOL, TELAGA AIR, SARAWAK.
Intan Rohayu binti Sukimin
Aquatic Resource Science and Management Programme
Faculty of Resource Science and Technology
Universiti Malaysia Sarawak
ABSTRACT
A study on the distribution and population structure of sand dollars across intertidal zone was
conducted at Pandan Beach, Lundu (January, 2014) and Trombol, Telaga Air (October, 2013),
Sarawak. This study aims to determine the distribution and population structure of sand dollars
across intertidal zone; and to compare the presence of these organisms in two different areas, with
the pore water parameters and sediment type. Sand dollar specimens were collected along line
transects within quadrats. Simultaneously, sediment and selected parameter of pore water (pH,
salinity, temperature) were recorded. Two species were found at both study areas namely
Arachnoides placenta and Echinodiscus tenuissimus. Results indicate that there were significant
difference (One Way ANOVA and Linear regression, p < 0.05) of density and test diameter of
adult and juvenile sand dollars across intertidal zone at Trombol only. Furthermore at Lundu,
significant negative correlation was showed between sediment (silt and clay) and density of
juvenile sand dollars. At Trombol, positive significant correlation was showed between salinity and
density of juvenile sand dollars. Thus, further study can be carried out to determine why certain
parameters influence more on the juvenile rather than the adult sand dollars.
Key words: Sand dollar, density, adult, juvenile, diameter
ABSTRAK
Kajian tentang taburan dan struktur populasi ‘deduit laut’ sepanjang zon pasang surut telah
dijalankan di Pantai Pandan, Lundu (Januari, 2014) dan Trombol, Telaga Air (Oktober, 2013),
Sarawak. Kajian ini bertujuan untuk mengkaji taburan dan struktur populasi ‘deduit laut’
sepanjang zon pasang surut; dan seterusnya membandingkan kehadiran organism ini di dua
kawasan berbeza, dengan parameter air liang dan jenis sedimen. Spesimen ‘deduit laut’ telah
dikutip menggunakan transek garisan yang terdapat dalam kuadrat. Seterusnya, sedimendan
parameter air liang yang dipilih (pH, kemasinan, suhu) dicatat. Dua spesis telah dijumpai di dua
kawasan kajian iaitu Arachnoides placenta dan Echinodiscus tenuissimus. Hasil kajian mendapati
terdapat perbezaan yang signifikan (ANOVA sehala dan regresi linear, p <0.05) pada kepadatan
dan diameter test’deduit laut’ juvenil dan dewasa sepanjang zon pasang surut di Trombol sahaja.
Seterusnya di Lundu, signifikan korelasi negatif telah ditunjukkan antara butiran sedimen (kelodak
dan tanah liat) dengan kepadatan ‘deduit laut’. Walaubagaimanapun di Trombol, signifikan positif
korelasi telah ditunjukkan antara kemasinan dengan kepadatan ‘deduit laut’ juvenile. Oleh yang
demikian, kajian lanjut boleh di jalankan untuk mengkaji mengapa parameter tertentu lebih
mempengaruhi ‘deduit laut’ peringkat juvenil berbanding dengan dewasa.
Kata kunci: ‘Deduit laut’, kepadatan, dewasa, juvenil, diameter
1
1.0
INTRODUCTION
Sand dollar is a macrobenthic marine invertebrate of Phylum Echinodermata, (Order
Clypeasteroids) that is spiny and has coin shaped test (flattened disc). It is also described as
a type of irregular sea urchin (Superorder Gnathostomata) which displays varying degree
of radial symmetry and commonly found across intertidal zone. The body of sand dollar
(aboral and oral surface) is covered by short spines that allow this animal to undergo
feeding process while its flat shape test helps in the burrowing process into the sediment
during low tide (Haycock, 2004).
Sand dollar (Arachnoides placenta) is easily found in great abundance at intertidal
zone of beach and burrowing on sand bars at 2-5 cm depth at intertidal zone (Haycock,
2004). Sand dollar occurs in high densities on medium to fine sand substrata (Aung, 1975)
and exposed during low tide thus allowing sampling and collection of the specimens.
However, other sand dollar species can also inhabit the subtidal zone ranging from 16 to 57
m deep (Aung, 1975). The burrowing behaviour of sand dollar on sandy beach is to avoid
predation by fishes, crabs and sea stars and also to avoid dehydration during low tide
exposure (Haycock, 2004).
Sand dollar plays important role in ecological structure. First, sand dollar acts as
predator to diatom, algae and detritus, while it becomes prey for fishes, crab and sea stars
(Aung, 1975). Thus it maintains the stability in food chain relationship of the ocean. The
second ecological role of sand dollar is as reworking sediments and recycling nutrients in
the benthic community at intertidal zone of sandy beach (Bell and Frey, 1969).
There are a few studies and papers dealing with sand dollar had been published. Most
focused on the population biology (Palumbi et al., 1997), reproduction and recruitment biology
(Aung, 1975; Cameron and Rumrill, 1982), the distribution (Haycock, 2004; Nebelsick, 1992), the
2
ecology (Chao, 2000; Wang, 1984) and finally about sediment preference (Lawrence and Feber,
1971). In tropical country, some study about the distribution of sand dollar had been published by
the authors Hines and Kenny (1967). However, in Malaysia, detail study on sand dollar is limited
and mostly reported as side finding of other bigger topics that cause limited information about
their distribution (Ahmad et al., 2011) and (Sasekumar et al., 2010).
Thus, this study aims to:
1.
To determine the distribution of sand dollar across intertidal zone at selected beaches at
Pandan Beach, Lundu and Trombol, Telaga Air, Sarawak.
2.
To determine the population structure of sand dollar across intertidal zone at selected
beaches at Pandan Beach, Lundu and Trombol, Telaga Air, Sarawak.
3.
To determine the relationship between pore water parameters and sediment particle size
on the density of sand dollar at both study areas.
3
2.0
LITERATURE REVIEWS
2.1 Introduction to Sand Dollar
Sand dollar or also known as sand cake and cake urchin which refer to species that
extremely flattened, burrowing sea urchins and belonging to Phylum Echinodermata. It
posses a rigid skeleton or test that is made up from calcium carbonate plates (Haycock,
2004).
2.2
Classification of Sand Dollar
Taxanomic classification of sand dollar based on Aung (1975) and Haycock (2004):
Phylum: Echinodermata
Class: Echinoidea
Subclass: Euechinoidea
Superorder: Gnathostomata
Order: Clypeasteroida
Suborders and families:
Suborder: Clypeasterina
Family: Arachnoididae
Genus: Arachnoides
Species: A. placenta (Linnaeus, 1758) –
tropical sand dollar
Family: Clypeasteridae
Genus: Clypeaster
Suborder: Laganina
Family: Fibulariidae
Family: Laganidae
4
Suborder: Rotulina
Family: Rotulidae
Suborder: Scutellina
Family: Astriclypeidae
Family: Dendrasteridae
Genus: Dendraster
Species: D. excentricus– eccentric sand dollar,
Pacific sanddollar, western sand dollar
Family: Echinarachniidae
Genus: Echinarachnius
Species: E. parma – temperate and tropical sand
dollar
Family: Mellitidae
Genus: Mellita
Species: M. quinquiesperforata
2.3
Aggregation and Patchiness of Sand Dollar
Intertidal and subtidal zones are constantly influence by physical and biological conditions
which cause patchy population distribution of sand dollar (Haycock, 2004; Swigart and
Lawrence, 2008). The examples of physical conditions are wave action, condition of
sediment, availability of food, temperature and salinity of sea water while biological
factors include competition and prey predation (Bell and Frey, 1969 cited in Haycock,
2004).
Sand dollars will form aggregation normally for breeding (Moore, 1956). The West
Coast of North America of subtidal sand dollar form large scale distribution which affected
5
water depth, current, and sediment grain size on that habitat (Swigart and Lawrence, 2008).
Based on Aung (1975) study at Queensland, Australia the species of sand dollar A.
placenta were mostly found at medium–fine wet sediment where food is present in great
abundance. However, there is no evidence about long term aggregation of A. placenta in
high number throughout the years (Aung, 1975). The protected areas of sand flats are
preferred by Mellita quinquiesperforata (Swigart and Lawrence, 2008). Meanwhile, A.
placenta also has the tendency to be more abundant behind sand bars and in pools of water
between ripples because the water is calm and accumulation of silt (Aung, 1975).
The density of sand dollar population may fluctuate throughout the years whereby
highest density occur after new recruitment of juveniles and decreased after that due to
mortality (Chia, 1969). Vertical migrations in and out of a study area can cause changes in
density and distribution pattern of adults of sand dollar population. Haycock (2004) noted
that high density of sand dollar (A. placenta) (1000 ind/m²) may increase food capturing
and fertilization process especially in inclined position. Based on Cabanac and
Himmelman (1996) which study at northern Gulf of St. Lawrence, eastern Canada reported
that size distributions of E. parma (subtidal species) showed the presence of two major
groups measuring 1-21 mm and 37-62 mm in diameter, respectively while intermediatesized sand dollar is rare. Juveniles of E. parma (< 28 mm in diameter) were extremely
abundant at higher depth about 16 to 20 m depth on subtidal zone and decreased in number
with decreasing depths, whereas, the density of adults E. parma (> 28 mm in diameter)
were relatively stable at different depths (Cabanac and Himmelman, 1996).
2.4
Sediment Particle size Preferred by Sand Dollar
Adults and juveniles of certain sand dollar species (A. placenta, E. parma and Dendraster
excentricus) prefer different sediment particle size (Buchanan, 1966). Normally sand
6
dollars can be found on the medium to fine grain sand of sediment (Pomory et al., 1995).
But according to Harold and Telford (1982) the sediment ranging from coarse gravelly
sand to silt is habitat preference for E. parma. Meanwhile for Mellita tenuissimus is found
in fine to coarse sand sediment and for Encope michelini dominant on fine sand to fine
gravel (Hilber, 2006).
The sediment particle size has some impacts on the burrowing behaviour of sand
dollar and distribution across intertidal zone (Ahmad et al., 2011) and feeding (Swigart and
Lawrence, 2008). According to Pomory et al. (1995), the particles that can enter the food
groves of sand dollar are < 500 μm and often < 250 μm showing the preference of small
particles in their food. Aung (1975) reported that adult of A. placenta prefer the fine to
medium particle size substrata. However, particles that is very fine may block feeding
apparatus of A. placenta which may trapped in mucous strand (used as to carry small
medium sand grain to mouth) (Buchanan, 1966). Sand dollar may burrows through
sediment down to a few cm below surface (Haycock, 2004).
2.5
Feeding, Burrowing and Locomotion Behaviour of Sand Dollar
Feeding, burrowing and locomotion behaviour of adults and juveniles of sand dollar are
usually related to sediment characteristics which most of them preferred small particle size
(Aung, 1975). Sand dollar can actively move, bury themselves and move on sand surface
for feeding (Bell and Frey, 1969 cited in Haycock, 2004). Some species of sand dollar will
bury themselves into 5 cm deep particularly on sand bars that aims to prevent dehydration
while, juveniles of sand dollar of A. placenta (< 10 mm length of test diameter) will bury
themselves in response to avoid water turbulence especially during storm (Aung, 1975).
7
2.6
Feeding Mechanism
Sand dollar is generally being considered as deposit feeders. They prefer to feed on small
size particles because they have aboral spines that act as sieve to select certain size of
particles and also podiaon oral surface that are used for collect food (Haycock, 2004). For
some species of sand dollar, they require a stable substratum for suspension feeding of
algae and diatom (Aung, 1975). The feeding apparatus of sand dollar is located in the
centre on its oral side of the test (Figure 1).
Mouth
Figure 1: The morphological structure of sand dollar (the oral surface containing mouth in the centre).
(Source: Haycock, 2004).
2.7
Food Preference
The gut content of M. quinquiesperforata showed that ingestion of inorganic and organic
detritus where the example of inorganic materials are sand grains, frustules of diatom,
sponge, fragment of copepod and silt while organic particles are dead of dinoflagellate, bits
of plant material and pollen grains of seagrass (Lane and Lawrence, 1982). Sand dollar will
move to shallower water with increasing size to take advantage of food resources, possibly
benthic diatom which are more abundant there (Haycock, 2004).
8
3. MATERIALS and METHODS
3.1 Description of Study Site
This study was conducted at two selected intertidal areas namely Pandan Beach, Lundu
(January, 2014), and Trombol, Telaga Air (October, 2013), Sarawak (Figure 2).
South China Sea
Pandan Beach
Lundu
Kuching
Trombol
Figure 2: Locations of study sites. (a) Pandan Beach, Lundu and (b) Trombol, Telaga Air.
9
3.2 Sampling and Sand Dollar Collection
Sand dollar samples were collected at two sampling sites namely Pandan Beach, Lundu
(Figure 2a) and Trombol, Telaga Air (Figure 2b) during low tide of spring tide. Three line
transect were laid perpendicular to the beach from high tide to low tide zone (Figure 3).
The distance between line transect was 100 m and quadrate was placed at 50 m distance
along each line transect. Three quadrates were conducted at Lundu while six quadrates at
Trombol. Two sizes of quadrates were used: (1) 1 m² and (2) 0.25 m². The bigger quadrate
was 1 m² for collecting adult sand dollar samples which can be early detected by naked
eyes and was put into the plastic bag with labelling and fixed with 5% buffered formalin.
The coordinates of each quadrate were recorded using GPS (GARMIN, 60CSX). Smaller
quadrate is for the juveniles, the size quadrate is 0.25 m² was made adjacent to adult
quadrate and sediment within the small quadrate was scraped out to a depth of 1 cm and
sieved through 1000 μm sieve to collect juvenile sand dollars. All the juveniles that remain
inside the sieve were put into labelled plastic bag and fixed with 5% buffered formalin.
Meanwhile for sediment grain size analysis triplicate of 10 cm deep sediments core were
collected at each quadrate. Selected parameters of pore water such as the salinity, pH and
sediment temperature were measured using salinometer (Milwaukee, MA887), pH meter
(Hanna Instrument) and thermometer probe (Traceable) respectively.
10
Supralittoral
zone
T1
100 m
T2
100 m T3
Q1
1
0.25 m²
50 m
1 m² Juvenile quadrate
Adult quadrate
Q2
Intertidal
zone
Qn
T= Transect
Water edge
Subtidal
zone
Q= Quadrate
Figure 3: Illustration of three line transects across the intertidal zone from high tide to low tide zones.
11
3.3 Morphometric Measurements and Identifications of Sand Dollars
All sand dollar samples were identified according to their morphological characteristics
using Heinke (2010). In addition, test diameter of each sand dollar was measured using dial
calliper (Mitutoyo) to the nearest 0.02 mm. Later, all samples were preserved with 70 %
ethanol.
Table 1: Key to major taxa of Arachnoides placenta and Echinodiscus tenuissimus.
No
1.1
2.1
2.2
3.1
3.2
Morphology
Bilateral symmetry, periproct opening
(pp) not opposing to peristome
Peristome central, oral
interambulacral zones similar
(shadowed).
Peristome anterior, oral posterior
interambulacrum differentiated
Enlarged pores (phyllodes) adjacent
to the peristome (pm)
No enlarge pores adjacent to the
peristome (pm).
Taxa
Irregular
Direction
Go to 2.1
Neognathostomata
Go to 3.2
Atelostomata
Cassiduloida
Clypeasteroida:
3.1.1 Arachnoididae
3.1.2 Astriclypeidae
12
Arachnoides
placenta
Echinodiscus
tenuissimus