Lab 6: Senses, Suckers, and Catfish channel catfish (Ictalurus punctatus)golden redhorse (Moxostoma erythrurum)

Four main sensory systems in fish Chemoreception – olfaction and taste Acoustico-lateralis – hearing and lat. line Electroreception Photoreception/vision

Chemoreception -- olfaction Olfaction “smell” –Nares –Used for food detection, orientation, predator avoidance Nare function of american eel (Anguilla anguilla)

Nares of different fishes The # of lamellae (folds) usually correlate with the ability to smell Range from 0 (seahorses) to 230 (porgy).

Chemoreception Examples Salmonid homing – adults use nares to detect chemical signature of native stream Cyprinids, Catostomids use papillae on their lips Ictalurids use barbels, note the orientation of the barbels How do you test these senses….plug or block them!

Auditory Systems-- Acoustico-lateralis Inner ear and otoliths Swim bladder and Weberian apparatus Lateral Line

Inner Ear -- Otolith Otolith (hard earstone) – held in a fluid sac, saculus, 3x density Hairs inside the sac detect otoliths movement, fish moves otolith stays in place cause it is more dense Also balances the fish in three planes

Swimbladder and Weberian Apparatus Bony connection between swimbladder and inner ear, Dense water  less dense air causes swim bladder to vibrate, the Weberian apparatus transmit vibrations to the inner ear.

Lateral line – “distant touch” Neuromast Hair cells

Electroreception Widespread among fishes….except teleosts –Freshwater examples: gymnotid, electric catfishes, African electricfishes…the mormyridae, really cool! –Useful in finding food, especially in turbid environments

Vision Most can see color, but more rods then cones Rods are much more precise, therefore used to detect movement Tapetum lucidum, which amplifies the incoming light, layer of guanine crystals which glow at night.

Eye orientation determines what a fish can see….evolutionary consequences

Eyes of Wisconsin fishes

Fish Identification Catostomidae and Ictaluridae

Family Catostomidae -- suckers Small family only 68 species but successful In North America often most abundant Primarily bottom dwellars Subterminal mouths, fleshy Fins in primitive position Two main forms  Lotic and lentic….? White sucker (Catastomus commersoni)

First, what does lotic or lentic mean…? Lotic – running water  streams, rivers Lentic – standing water  lakes, ponds How do you remember the difference….? Lotic = Flowing

Lotic and lentic catostomids LOTIC

Lotic and lentic catostomids LENTIC smallmouth buffalo (Ictiobus bubalus) carpsucker

Lotic and lentic catostomids In Betweens White sucker Catostomus commersoni Quillback Carpiodes cyprinus

Genus Catostomus White sucker (Catostomus commersoni) Lips are very papillose (bumpy)

Shorthead redhorse (Moxostoma macrolepidotum) Golden redhorse (Moxostoma erythrurum ) Large scales, larger then Catostomus Lower lip formed differently between two species Shorthead redhorse (Moxostoma macrolepidotum) Genus Moxostoma Golden redhorse (Moxostoma erythrurum)

Genus Hypentelium Northern hog sucker (Hypentelium nigricans) Have indented head 3 saddle patches on back

Quillback (Carpiodes cyprinus) –Have extended ray on dorsal fin –Subtriangular subopercle Genus Carpiodes

Genus Ictiobus nevermind Smallmouth buffalo (Ictiobus bubalus) Looks like a carp with no barbels or spines Semicircular Subopercle

Family Ictaluridae -- Catfishes Whiskery snout, 1-4 pair of barbels, 1 from maxillae Small eyes Flattened head Adipose fin With or without sclaes, some with bony plates Stout spine from pectoral and dorsal fins

Catfishes - Armour

Genus Ameiurus -- bullheads black bullhead (Ameiurus melas) brown bullhead (Ameiurus nebulosus)yellow bullhead (Ameiurus natalis) Black, yellow, and brown bullheads Look at CHIN barbels first, yellow bullhead are lighter then black or brown Black bullhead all one color, brown are mottled

Genus Noturus -- madtoms Stonecat Noturus flavus Tadpole madtom Noturus gyrinus Look at adipose fin and caudal fin, distinct adipose are bullheads, connected or almost connected are madtoms Tadpole madtom (Noturus gyrinus)Stonecat (Noturus flavus) Connected – no notch

Genus Ictalurus Channel catfish Ictalurus punctatus Deeply forked tail Channel catfish Bullhead