Taxonomy of fishes
classification
hierarchical grouping of organisms (used by Linnaeus,1758)
taxonomy
science of biological nomenclature (formal rules for use)
systematics
the study of relationships
Taxonomic hierarchy:
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Actinopterygii (formerly Osteichthyes)
Order: Cypriniformes
Family: Cyprinidae
Genus: Cyprinus
Species: carpio (common carp)
additional standardized endings:
Suborder:
- oides
Subfamily:
- inae
Tribe:
- ini
Taxonomic hierarchy:
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Actinopterygii (formerly Osteichthyes)
- Subclass Neopterygii
- Infraclass Teleostei
Order: Cypriniformes
Family: Cyprinidae
Genus: Cyprinus
Species: carpio (common carp)
Tools of taxonomy:
morphometrics
- measurements relative to length
meristics
- counts
Tools of taxonomy:
morphometrics
- measurements relative to length
meristics
- counts
anatomical traits - shape, presence/absence
Tools of taxonomy:
morphometrics
- measurements relative to length
meristics
- counts
anatomical traits - shape, presence/absence
color patterns
white crappie (Pomoxis annularis)
black crappie (Pomoxis nigromaculatus)
Tools of taxonomy:
morphometrics
- measurements relative to length
meristics
- counts
anatomical traits - shape, presence/absence
color patterns
karyotypes – chromosome counts,
shape, banding patterns
biochemical methods
Tools of taxonomy:
physiological differences (e.g., temperature preferences)
behavior
steelhead trout (Oncorhynchus mykiss)
rainbow trout (Oncorhynchus mykiss)
Tools of taxonomy:
physiological differences (e.g., temperature preferences)
behavior
steelhead trout (Oncorhynchus mykiss)
rainbow trout (Oncorhynchus mykiss)
diet
lake trout (Salvelinus namaycush)
Use of standardized descriptions:
Round goby, Neogobius melanostomus (Pallas, 1811).
D1 VI (V-VII); D2 I + 14-16 (13-16); A 1 + 11-13 (11-14); P 18-19
(17-20).
Scaled on the parietal region, nape, back (all), throat (all or most),
abdomen, pectoral fin peduncles, and one quarter of the gill covers.
Scales on the middle and anterior nape are cycloid. Head is as wide as
or wider than deep; depth is 0.9-1.2 times the width. Head length
4.2-4.5 of total body length. Angle of the jaw below the anterior quarter
of the eye. Lower jaw not prominent. Snout 1.1-1.4 times the orbit
diameter. Upper lip narrows slightly to the rear. Usually 6, rarely 7,
transverse suborbital series of pit organs. Ventral fins reach or almost
reach the vent. Pelvic disk is 0.6-0.8 times the abdomen length. If
present, the anterior membrane width is very shallow, with rounded,
lateral lobes. Caudal peduncle depth is about two-thirds its length.
Lacks a gas bladder and chemoreceptors.
Use of standardized descriptions:
Round goby, Neogobius melanostomus (Pallas, 1811).
placed in genus of nearest
(known) related species
Use of standardized descriptions:
Round goby, Neogobius melanostomus (Pallas, 1811).
sources of species names:
descriptive (melanostomus)
discoverer, etc. (hubbsi)
local language (namaycush)
Use of standardized descriptions:
Round goby, Neogobius melanostomus (Pallas, 1811).
Originally discovered and named by Pallas in 1811
- but name has since changed
Use of standardized descriptions:
Round goby, Neogobius melanostomus (Pallas, 1811)
D1 VI (V-VII); D2 I + 14-16 (13-16); A 1 + 11-13 (11-14); P 18-19 (17-20).
D1 VI (V-VII); the anterior dorsal fin has 6 spines, ranging from 5-7
D2 I + 14-16 (13-16); the posterior dorsal fin has one spine
and 14-16 soft rays, ranging from 13-16
A 1 + 11-13 (11-14); the anal fin has one spine, 11-13
soft rays, ranging from 11-14
P 18-19 (17-20). the pectoral fins have 18-19
soft rays, ranging from 17-20
Use of standardized descriptions:
Round goby, Neogobius melanostomus (Pallas, 1811).
D1 VI (V-VII); D2 I + 14-16 (13-16); A 1 + 11-13 (11-14); P 18-19
(17-20).
Scaled on the parietal region, nape, back (all), throat (all or most),
abdomen, pectoral fin peduncles, and one quarter of the gill covers.
Scales on the middle and anterior nape are cycloid.
Head is as wide as or wider than deep; depth is 0.9-1.2 times the width.
Head length 4.2-4.5 of total body length. Angle of the jaw below the
anterior quarter of the eye. Lower jaw not prominent. Snout 1.1-1.4
times the orbit diameter. Upper lip narrows slightly to the rear. Usually
6, rarely 7, transverse suborbital series of pit organs.
Ventral fins reach or almost reach the vent. Pelvic disk is 0.6-0.8 times
the abdomen length. If present, the anterior membrane width is very
shallow, with rounded, lateral lobes.
Caudal peduncle depth is about two-thirds its length.
Lacks a gas bladder and chemoreceptors.
Authorship of scientific names
International Commission on Zoological Nomenclature
right of priority – you discover it, you name it
species name will (almost) never change
type specimen – archived original specimen
type locality – location of first discovery
nominal species – name of a species defined by type specimen
nomen praeoccupatum – name already in use
junior synonyms – name with later publication date than
accepted name
Authorship of scientific names
right of priority
type specimen
type locality
nominal species
nomen praeoccupatum
junior synonyms
Authorship of scientific names
Salmo Omisco Maycus
- Walbaum 1792
(type locality Hudson Bay)
Percopsis guttatus
- Agassiz 1850
Salmoperca pellucida
- Thompson 1853
Percopsis omiscomaycus (Walbaum) - Kendall 1911
_______________________
Percopsis: perch-like
omiscomaycus: probably Algonquin name with root meaning “trout”
Common names: trout-perch, silver chub, omisco
Authorship of scientific names
right of priority
type specimen
type locality
nominal species
nomen praeoccupatum
junior synonyms
Salmo gairdneri Richardson 1836
synonymous with Salmo mykiss Walbaum 1792
but it is really a Pacific salmon (Oncorhynchus)
- so it becomes Oncorhynchus mykiss (Walbaum 1792)
On Discovering a Butterfly
I found it and named it, being versed
in taxonomic Latin; thus became
godfather to an insect and its first
describer -- and I want no other fame.
Wide open on its pin (though fast asleep),
and safe from creeping relatives and rust,
in the secluded stronghold where we keep
type specimens it will transcend its dust.
Dark pictures, thrones, the stones that pilgrims kiss,
poems that take a thousand years to die
but ape the immortality of this
red label on a little butterfly.
-Vladimir Nabokov
Nomenclature (International Code of Zoological Nomenclature)
use of Latin, Greek
prononciation:
ch = k (e.g., ichthyology)
initial c = s (e.g., Cyprinidae)
hybrids: Rutilus rutilus x Abramis brama
genus and species always italicized
Neogobius melanostomus
genus, species with subspecies - species abbreviated
N. melanostomus
N. m. caspia
subgenus usually in parentheses
Dreissena (Pontodreissena) polymorpha
Nomenclature (International Code of Zoological Nomenclature)
problems with common names:
Oncorhynchus – true salmon
rainbow trout
Chinook salmon
Salmo – trout
brown trout
Atlantic salmon
Salvelinus – char (or charr)
lake trout
brook trout
Arctic char
creek chub, longjaw chub, grey chub, Bermuda chub, etc.
cisco….
What does this creature have to do with fish taxonomy???
Phylogenetic systematics (cladistics)
non-arbitrary, informative classifications
reflect evolutionary relationships – evolutionary hypotheses
task is to identify monophyletic groups (clades)
Phylogenetic systematics (cladistics)
“task” of phylogeny is to determine whether characters shared
among taxa are
primitive (plesiomorphies – primitive character states)
or derived (apomorphies – advanced character states)
homologous – identical by ancestry
or convergent – similar by convergent evolution
Phylogenetic systematics (cladistics)
monophyletic groups (clades)
– members share common ancestor
– all members have common derived character or synapomorphy
cladogram
Phylogenetic systematics (cladistics)
avoid paraphyletic groups - monophyletic group that excludes some of the
descendants
Phylogenetic systematics (cladistics)
avoid paraphyletic groups - monophyletic group that excludes some of the
descendants
or polyphyletic groups - consists of members from two monophyletic
groups (e.g. flying animals; eel-like animals)
Myxiniformes Petromyzontiformes Gnathostomata
(hagfishes)
(lampreys)
(jawed fishes)
Agnatha
(jawless fishes)
Agnatha is now
paraphyletic
Myxiniformes Petromyzontiformes Gnathostomata
(hagfishes)
(lampreys)
(jawed fishes)
Where do these fish belong, phylogenetically?
Phylogenetic systematics (cladistics)
Characteristics of the extant classes of fishes
Character
skeleton
paired fins
gill arches
nostril(s)
jaws
fins with spines
pectoral fins
Primitive
Advanced
cartilaginous
ossified
absent (lamprey)
present*
absent
present
one, median
paired
absent
present
absent (trout)
present (perches)*
horizontal base low on vertical base high
body (minnows)
on body (basses)*
pelvic fins
far back on belly
forward, attached to pectoral girdle
tail
heterocercal
homocercal
scales
cycloid
ctenoid
mouth
front of head
up- or down-turned*
* subsequently modified in some advanced fishes