lab 6: senses, suckers, and catfish channel catfish (ictalurus punctatus)golden redhorse (moxostoma...
TRANSCRIPT
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 waterless 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
carpsucker
Lotic and lentic catostomids
In Betweens
White suckerCatostomuscommersoni
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(Moxostomaerythrurum)
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 -- CatfishesWhiskery 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