WFB 232 Ichthyology Taxonomy, Week 6 7 March 2005 SUPERCLASS GNATHOSTOMATA Class Actinopterygii Subclass Neopterygii Division Teleostei Subdivision Euteleostei Superorder Protacanthopterygii Order Esociformes (Pikes, mudminnows) No adipose fin, soft-rayed, physostomic, no teeth on maxillaries Distributed throughout North America and Eurasia Family Esocidae (pikes) Freshwater Piscivorous, with voracious appetites, will also eat other pike Found in lakes & slow rivers, in shallow water Elongate body (sagittiform), long snout/jaws, with sharp teeth (piscivorous) Dorsal & anal fins situated far back on body, near caudal region. Highly prized sportfish; also commercial fishery in Eurasia Esox masquinongy can reach several feet in length, 40-60 lbs. IN VERMONT: Redfin pickerel, Esox americanus americanus Chain pickerel, Esox niger Northern pike, Esox lucius Muskellunge, Esox masquinongy Family Umbridae (Mudminnows) Small – less than 15 cm long; freshwater Prefer slow water – bogs, slow streams, feed on invertebrates (plankton & insects) Hide in mud when disturbed – can tolerate dry periods by burrowing in sediments Disjunct distribution - 1 genus, Umbra, with 4 species worldwide – central Europe, central N. America, Atlantic coast of N. America, and Olympic Peninsula in the state of Washington. IN VERMONT: Central mudminnow, Umbra limi - 1 - Order Osmeriformes (smelts, argentines, salangids, galaxiids) Marine, freshwater, & anadromous species – distributed worldwide No nuptial tubercles, most have adipose fin Some species can estivate in droughts, others emit odor similar to cucumbers! Generally silvery in color; some deep-sea species are bioluminescent Southern grayling – Australia region (Not a salmonid grayling) – only right gonad is present Family Osmeridae (smelts) Fresh & salt water, 7 genera, 11 species Popular food fish, spawn in sand or gravel in large numbers (good for dip netting) Ayu – Japanese “sweetfish” – captured using cormorants tethered to a boat IN VERMONT: Osmerus mordax, Rainbow smelt Order Salmoniformes 1 extant family – Salmonidae (trouts, salmons, chars, whitefishes, graylings) Soft rayed, physostomus, swim bladder, adipose fin Many species are sport fishes; widely stocked worldwide for sport fishing Freshwater, landlocked, or anadromous Endemic to entire northern hemisphere; many have been transplanted in southern hemisphere Mostly piscivorous Most Pacific salmon are reknowned for their homing abilities – highly selective to their natal tributary when returning from the ocean to spawn. Cretaceous period – 144 MYA, probably basal group for higher fishes IN VERMONT: Charr: Salvelinus fontinalis, brook trout Salvelinus namaycush, lake trout Trout: Salmo salar, Atlantic salmon Salmo trutta, brown trout Salmon: Oncorhynchus mykiss, rainbow trout Whitefish: Coregonus artedii, cisco or lake herring Proscopium cylindraceum, round whitefish Coregonus clupeaformis, lake whitefish - 2 -.