A Fish Primer WMAN 445 Intro Fish Management August 31, 2006

Why Study Fish? Academic –Most diverse group of vertebrates –Most ancestral vertebrate group Understanding their evolutionary relationships helps us understand the more derived groups Applied –Commercial and Recreational Fisheries –Aquatic Health Indicators

Great Species Diversity 25,000 species (28,500) More than any other vertebrate group –4,000 mammals –9,000 birds –7,000 reptiles –5-6,000 reptiles Total of other vertebrates = 25-26,000 1 of every 2 vertebrates is a fish

Great Diversity in… Size (blenny – whale shark) Shape (sea horses, rays, eels) Habitats occupied (streams, ponds, rivers, bays, ocean, reefs, caves, thermal springs) Feeding habits (benthic, engulfers, shredders, cleaners, parasites, omnivores) Reproduction (oviparity, viviparity, sex reversal, semelparity, sneakers, mimics)

World Distribution of Fishes Earth’s water –97% ocean –2.99% ice –0.01% freshwater Why are so many fish species found in freshwater? –Isolation limits gene flow—speciation events occur –Diversity of habitats and evolutionary niches Fish Distribution –41% freshwater –58% marine –1% diadramous / euryhaline

N.A. Distribution of Fishes About 950 species 75% occur in the eastern U.S. Mississippi River drainage most diverse –Tennessee drainage most diverse –Atlantic slope least diverse –New / Kanawha River basin “relatively diverse”

Fishes in Peril Fastest declining vertebrate group –Dams –Pollution –Habitat Alteration –Introduced species –Over harvest

Fishes in Peril

What is a Fish? AquaticPoikilotherm Gill Breathing Single-Loop Circulation Vertebrate/Craniate Fins (as opposed to pentadactyl limbs)

Fish Classification Binomial Name –Genus specific epithet name of describer & year –E.g. Lepomis macrochirus Rafinesque 1819 –E.g. Lepomis megalotis (Rafinesque 1820) Lepomis = scale shoulder megalotis = large ear

Classification in General KingdomPhylumClassOrderFamilyGenusSpecies Higher taxonomic level the more inclusive of groups –Reflects natural evolution of groups

Fish Classification Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Superclass: Agnatha –Order: Petromyzontiformes Family: Petromyzontidae (Lampreys) –Most primitive, no jaws, parasitic, non-parasitic, eel-like Superclass: Gnathostomata –Class: Chondrychthys (cartilaginous fishes) –Class: Osteichthyes (bony fishes) 24,000 living forms Largest class of vertebrates

General Characteristics of Bony Fishes Lungs –Fish evolved in tropic freshwater environments –Modified into buoyancy organs (swim bladders) Bone –Secondarily replaced by cartilage in paddlefish, sturgeon Bony scales –Lost in many species (sculpins) Lepidotrichia –Segmented structural supports for fins; soft fin ray

Subclasses of Osteichthyes Sarcopterygii (lobe finned fishes) –Ancestor to tetrapods Actinopterygii (ray finned fishes) –Infraclass Chondrostei (sturgeons, paddlefishes) Order Acipenseriformes –Acipenseridae: sturgeons Caviar, cartilaginous, bottom feeder, long-lived, slow growth –Polyodontidae: paddlefishes Planktivores, carnivores, long sensory snout, little native habitat –Infraclass Neopterygii (modern ray finned fishes) 4 diverse lineages Division Teleostei—main line of fish evolution

Order Lepisosteiformes –Lepisosteidae: gars Needle-like teeth Voracious predators –Amiiformes –Amiidae: bowfins Gulp air to fill air sac which is highly vascularized

Teleosts Order: Anguilliformes –Anguillidae: freshwater eels –Jawed fish, catadromous Order: Clupeiformes –Clupeidae: herrings/shad –Threadfin and gizzard shad (Dorosoma) –Alewife and American shad (Alosa) –Planktivorous –Marine, anadromous, can live in freshwater –Blocked by dams, introduced as prey

Teleosts Order Cypriniformes –Cyprinidae: minnows and carp Most diverse family (>2,000 species; 286 in N. A.) 57 species in WV Many are small Breeding coloration, tubercles, nest building –Catostomidae: suckers Bottom feeders, fleshy lips Diverse in large rivers

Teleosts Order Siluriformes –Ictaluridae: N.A. catfishes, bullheads, madtoms Barbles Largest freshwater fish family entirely indigenous to N. America Economically important: fishing and farming Pylodictis olivaris

Teleosts Order Esociformes –Esocidae: Pikes (Esox) Lie-in-wait predator 4 species, games fishes Chain Pickerel, Esox niger

Teleosts Order Salmoniformes –Salmonidae: salmon, trout, char, whitefish 3 species in 3 genera Oncorhynchus: Pacific salmon and western trout O. mykiss: rainbow trout (steel head) Salmo trutta: brown trout Salvelinus fontinalis: brook char Strong “homing” tendencies Introduced widely Cold water stenotherms

Teleosts Order Cyprinodontiformes –Fundulidae: killifishes –Poeciliidae: livebearers, topminnows Internal fertilization (gonopodium), live birth Guppies, Gila topminnow and mosquito fish –Cyprinodontidae: pupfishes Most are endangered Estuarine in origin Desert pupfish: endemic to desert spring environments as water dried up over geologic time

Teleosts Order Gasterosteiformes –Gasterosteidae: sticklebacks Territorial nest builders, elaborate courtship –Cottidae: sculpins Large pectoral fins No swim bladder Cottus: freshwater sculpins –cool-cold water streams –Bottom dwelling invertivore Cottus bairdi

Teleosts Order Perciformes –Moronidae : temperate basses Morone saxatilis: striped bass: anadromous Economically Important

Teleosts Order Perciformes –Centrarchidae: sunfishes, black basses Second largest fish family indigenous to N.A. Sexually dichromatic Hybridize Economically important Lepomis: sunfish Pomoxis: crappie Micropterus: black bass Lepomis cyanellus Pumpkinseed, Lepomis gibbosus Pomoxis nigromaculatus Micropterus salmoides

Teleosts Order Perciformes –Percidae: perches, walleye, darters, saugers Brilliant colors in darters Darters are benthic invertivores Economic importance of walleye, perch –Channidae: snakeheads Voracious predators, “swim” over land Northern Snakehead (Channa argus) rt/snakehead.html rt/snakehead.html Etheostoma blennioides Sander vitreus