taxonomy of fishes. classification hierarchical grouping of organisms (used by linnaeus,1758)...

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: - oidesSubfamily: - inaeTribe: - 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

diet

steelhead trout (Oncorhynchus mykiss) rainbow trout (Oncorhynchus mykiss)

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 namesright of prioritytype specimentype localitynominal speciesnomen praeoccupatumjunior synonyms

Authorship of scientific names

Salmo Omisco Maycus - Walbaum 1792 (type locality Hudson Bay)

Percopsis guttatus - Agassiz 1850Salmoperca pellucida - Thompson 1853Percopsis omiscomaycus (Walbaum) - Kendall 1911

_______________________Percopsis: perch-likeomiscomaycus: probably Algonquin name with root meaning “trout”

Common names: trout-perch, silver chub, omisco

Authorship of scientific namesright of prioritytype specimentype localitynominal speciesnomen praeoccupatumjunior synonyms

Salmo gairdneri Richardson 1836synonymous 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 versedin taxonomic Latin; thus becamegodfather to an insect and its firstdescriber -- 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 keeptype specimens it will transcend its dust.

Dark pictures, thrones, the stones that pilgrims kiss,poems that take a thousand years to diebut ape the immortality of thisred 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 abbreviatedN. melanostomusN. m. caspia

subgenus usually in parenthesesDreissena (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 troutbrook troutArctic 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)

“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 ancestryor convergent – similar by convergent evolution

Phylogenetic systematics (cladistics)

Phylogenetic systematics (cladistics)

monophyletic groups (clades)– members share common ancestor– all members have common derived character or synapomorphy

cladogram

Coelac

anth

s

Osteog

lossif

ormes

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)

Myxiniformes Petromyzontiformes Gnathostomata(hagfishes) (lampreys) (jawed fishes)

Agnatha(jawless fishes)

Agnatha is now paraphyletic

Phylogenetic systematics (cladistics)

Where do these fish belong, phylogenetically?

Characteristics of the extant classes of fishes

Character Primitive Advanced

skeleton cartilaginous ossified

paired fins absent (lamprey) present*

gill arches absent present

nostril(s) one, median paired

jaws absent present

fins with spines absent (trout) present (perches)*

pectoral fins 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

Phylogenetic systematics (cladistics)