Fish Anatomy

Fins:  Maintain position, move, steer, and stop

Single Fins
            - Dorsal
              - Caudal
            - Anal
            - Adipose

Paired Fins
            - Pectoral
            - Pelvic

Scales: Protection, like our skin

              - Ctenoid- jagged edges (usually fish with spines)
            - Cycloid- smooth rounded edges
              - Ganoid Diamond shaped (Gar)

Lateral line: a visible line along the side of a fish consisting of a series of sense organs that detect pressure and vibration.
               - Fluid filled sacs with hair-like sensory apparatus that are open to the water through a series of pores.
               - Senses- water pressure and currents, movement in the water

Ampullae of Lorenzini: are special sensing organs called electroreceptors, forming a network of jelly-filled pores.
               - Electric eels
               - Some species of Catfish
               - Sturgeon​

Swim Bladder: a gas-filled sac present in the body of many bony fishes, used to maintain and control buoyancy.
                - Hollow gas (usually oxygen) filled organ
                - Maintain neutral buoyancy
                - Without it a fish will sink if it stops swimming
                - Example of fish without swim bladders: sharks, rays
                - Some fish fill their swim bladder by gulping air at the surface others by internal processes 

Fish Mouths: Mouth shape and size determines what they can eat
​                 - Upward facing mouth-surface feeding
                 - Snout like nose-picks food out of crevices
                 - Bottom facing mouth-bottom feeder
                 - Mouth facing the middle- anything it can catch

Gills: Most fish breathe entirely with their gills flushing water over their highly vascularized gills

Air- breathing fish
                - Function similar to human lungs
                   - Fish gulp air to gain oxygen
                   - Store it in a primitive lung or modified organ
                   - Often found in habitats in which other fish cannot survive
​                   - Obligate vs non-obligate (have to breathe air vs can do it when oxygen levels in water are low)

Air breathing species we have in our collection:

• Gar
• Bichir
• Lungfish
• Catfish
• Electric Eel
• Knifefish
• Arowana
• Gourami