Taxonomy of fishes

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 But what are teleost fishes??

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) Pick apart these Latin names… actino: ray ichthyo: fish osteo: bone ptery: wing teleo: complete

KINGDOM ANIMALIA PHYLUM Chordata SUPERCLASS Agnatha Class Myxini (1 order) Class Cephalaspidomorphi (1 order) SUPERCLASS Gnathostomata Class Chondrichthyes (10 orders) sharks, rays, skates, chimeras Class Sarcopterygii (3 orders) lungfishes Class Actinopterygii (4 orders) ray-finned fishes Infraclass Teleostei (35-38 orders)

classification hierarchical grouping of organisms (used by Linnaeus,1758) taxonomy science of biological nomenclature (formal rules for use) systematics the study of relationships

What characteristics could be used to distinguish these fishes?

What characteristics could be used to distinguish these fishes?

Tools of taxonomy: morphometrics - measurements relative to length 8

Tools of taxonomy: morphometrics - measurements relative to length meristics - counts 9

Tools of taxonomy: morphometrics - measurements relative to length meristics - counts anatomical traits – e.g., presence/absence

Tools of taxonomy: morphometrics - measurements relative to length meristics - counts anatomical traits – e.g., presence/absence color patterns white crappie (Pomoxis annularis) black crappie (Pomoxis nigromaculatus) 11

Tools of taxonomy: morphometrics - measurements relative to length meristics - counts anatomical traits – e.g., presence/absence color patterns karyotypes – chromosome counts, shape, banding patterns

Tools of taxonomy: morphometrics - measurements relative to length meristics - counts anatomical traits – e.g., 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) 14

Tools of taxonomy: physiological differences (e.g., temperature preferences) behavior diet steelhead trout (Oncorhynchus mykiss) rainbow trout (Oncorhynchus mykiss) lake trout (Salvelinus namaycush) 15

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811). D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A I + 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, so his name is in parentheses

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811) D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A I + 11‑13 (11‑14); P 18‑19 (17‑20).

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811) D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A I + 11‑13 (11‑14); P 18‑19 (17‑20). D1 VI (V‑VII); the anterior dorsal fin has 6 spines, ranging from 5‑7

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811) D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A I + 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

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811) D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A I + 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

Use of standardized descriptions: Round goby, Neogobius melanostomus (Pallas, 1811) D1 VI (V‑VII); D2 I + 14‑16 (13‑16); A I + 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 I + 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 I + 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 - Kendall 1911 Thus, correct name is Percopsis omiscomaycus (Walbaum 1792) Percopsis: perch-like omiscomaycus: probably Algonquin name with root meaning “trout” Common names: trout-perch, silver chub, omisco Omiscomaycus - namaycush

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

How are names chosen, what do they mean? What’s in a name? How are names chosen, what do they mean? - descriptive (Perca flavescens) - honoring a scientist, colleague, etc. (Cottus bairdi; Barbus ansorgi, B. gulielmi) - local name or language (Salvelinus namaycush) - personal connection or tribute (Oregonichthys kalawatseti) The fish etymology project: http://www.etyfish.org/name-of-the-week/ William George Ansorgi – Welsh version of ‘William’ Kalawaset – diverse tribes of native Americans in Oregon, now declined/gone

Nomenclature (International Code of Zoological Nomenclature) use of Latin, Greek prononciation: ch = k (e.g., ichthyology) initial c = s (e.g., Cyprinidae) genus and species always italicized; genus capitalized, species not capitalized Neogobius melanostomus genus, species with subspecies - species abbreviated N. melanostomus N. m. caspia subgenus usually in parentheses Dreissena (Pontodreissena) polymorpha hybrids: Rutilus rutilus x Abramis brama

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….

Are these fish in the same family? Species? Why or why not?

Are these fish in the same family? Species? Why or why not?

Are these fish in the same family? Species? Why or why not?

Are these fish in the same family? Species? Why or why not?

Are these fish in the same family? Species? Why or why not?

But – what is a species? Lake trout (Salvelinus namaycush) Splake (Lake trout x Brook trout) - fertile Brook trout (Salvelinus fontinalis)

What does this creature have to do with fish taxonomy??? (hint: there’s more than one way of classifying species…) What does this creature have to do with fish taxonomy???

Phylogenetic systematics (cladistics) non-arbitrary, informative classifications that reflect evolutionary relationships – evolutionary hypotheses binary – based on single characters that are or are not present task is to identify monophyletic groups (clades) - all of the descendants of a common ancestor - share a common trait 43

Phylogenetic systematics (cladistics) monophyletic groups (clades) – members share common ancestor – all members have common derived character or synapomorphy Coelacanths Osteoglossiformes This cladogram illustrates a monophyly – or, encapsulate any part of the tree all the way to the right without leaving out right-hand members cladogram 44

polyphyletic groups - consists of members from two monophyletic groups (e.g. flying animals; eel-like animals) usually reflects convergent evolution ‘mistake’ paraphyletic group - monophyletic group that excludes some of the descendants

Phylogenetic systematics (cladistics) avoid paraphyletic groups - monophyletic group that excludes some of the descendants

Tetrapods … have jaws with fixed teeth, a bony skeleton, a skull with sutures, and heavy, paired appendages. …scales are not at all a defining character of fishiness, nor is breathing by way of gills. Therefore, based on many structural and physiological synapomorphies, the tetrapods not only share a common ancestor with the lobe-finned fishes, but are derived from them. The tetrapods are now generally believed to represent a subclass within the Sarcopterygii. And therein lies a major reason for the difficulties in defining fishes as a group. Fish - as the term is usually applied - is not a monophyletic taxon. R. Aidan Martin http://www.elasmo-research.org/education/classification/fishes.htm

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

look for patterns, sequences. Note changes in fin position look for patterns, sequences. Note changes in fin position. Job of the taxonomist to identify phylogenetically important features, vs. ecologically determined ones. Homologies vs congruencies (such as adipose fin)

Where do these fish belong, phylogenetically, in relation to each other? Congruencies – anguilliform shape

Phylogenetic systematics (cladistics) 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 Note that many of these traits have intermediate states (e.g., partially calcified skeletons)

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 is now paraphyletic Agnatha (jawless fishes) Myxiniformes Petromyzontiformes Gnathostomata (hagfishes) (lampreys) (jawed fishes)