FISH MORPHOLOGY: How does form affect function?

COLORATION Chromatophores Chromatophores Allows a fish to blend in with its environment Allows a fish to blend in with its environment May advertise that a fish is dangerous or poisonous May advertise that a fish is dangerous or poisonous Mate Selection Mate Selection

Camouflage

Countershading

Disruptive Coloration

Warning Coloration

Mouths Size and position indicate what fish eat Size and position indicate what fish eat

Breathing Take in water through mouth Take in water through mouth In bony fish, closing of operculum creates suction In bony fish, closing of operculum creates suction In cartilaginous fish, swim with mouth open In cartilaginous fish, swim with mouth open Water moves to pharynx, through gill rakers and over gill filaments where diffusion of gases occurs Water moves to pharynx, through gill rakers and over gill filaments where diffusion of gases occurs Water moves out through gill slits Water moves out through gill slits

OSMOREGULATION Control of the concentration of body fluids. Control of the concentration of body fluids. Affected by Osmosis Affected by Osmosis ells/Osmosis.htm ells/Osmosis.htm ells/Osmosis.htm ells/Osmosis.htm If a fish is unable to regulate the effects of osmosis it will die. If a fish is unable to regulate the effects of osmosis it will die.

Osmoregulation, cont. Bony fish Bony fish Drink water Drink water Kidneys/gills remove salt Kidneys/gills remove salt Little urine Little urine Cartilaginous fish Cartilaginous fish Retain urea – increases blood salt concentration Retain urea – increases blood salt concentration