Fish Anatomy & Physiology

Lateral line

A mechanoreceptor system consisting of a series of pores and receptor units (neuromasts) along the sides of the body of fishes and aquatic amphibians; detects water movements made by an animal itself and by other moving objects; gel filled pits

Cycloid scales

Bony fishes (teleosts) Overlapping grow with the fish (concentric rings) smooth outer edge (soft rayed fishes like salmon)

Ctenoid scales

Bony fishes (teleosts) overlapping grow with the fish (concentric rings) "toothed" outer edge (spiny fishes like basses)

Ganoid scales

Bowfin, paddlefish, gar, sturgeon contain bone non-overlapping armor-like plates

Placoid scales

Elasmobranchs flat basal plate under skin, point protrudes above skin related to vertebrate teeth do not "grow" to accommodate fish growth

Gill filaments

Fingerlike projections through which gases enter and leave the blood system-used for respiration, circulate blood, fleshy and red

Rays

Flexible; often branched; mainly for support

Scutes

Modified scales made from keratin seen on turtle shells, crocodiles, sturgeons

Gill arches

Multiple inside of cheek that sit on top of one another; one of the jointed and cartilaginous or bony structures behind the jaws in fish and larval amphibians

Spines

Rigid projections on fins; never segmented; defensive aid

Pyloric Caeac

food goes into sack and digestive fluid enzymes break down food

Incisor teeth

front teeth; cut

ampullary receptors

gel filled pits in skin that sense electricity concentrated on head ampullary canal filled with gelatinous matrix -n sharks and other fishes sensitive to electrical energy in environment

Molarlike teeth

grind

Maxillary teeth

line the edge of upper jaw; keeps prey in mouth

Terminal mouth

mouth located in the center of the head; midwater feeders; eat directly what is in front of them

Superior mouth

mouth opens upward--these fish are ambush predators that are surface feeders

Canine teeth

pointed, dog-like teeth next to the incisors; puncture

Gill rakers

spiked projections along the inner surface of fishes' gills used for filter-feeding

Barbels

stick off chin used to feel around bottom can find food and investigate environment

Caudal Fin

tail fin; propels the fish

Premaxillary teeth

teeth associated with the premaxilla along the anterior margin of the upper jaw

Palatine teeth

the teeth bones on the palatine bone, making up the anterior part of the inner tooth rows

Anal Fin

ventral fin that helps keep the fish upright and moving in a straight line; below the caudal fin

Vomer teeth

down below jaw

Inferior mouth

downward positioned mouth, used for bottom feeding

Adipose Fin

The fatty fin on some species of fish, such as catfish and bullheads; behind the dorsal fin

Pelvic Fin

either of a pair of fins attached to the pelvic girdle in fishes that help control the direction of movement, further down than the pectoral

Pectoral Fin

either of a pair of fins situated just behind the head in fishes that help control the direction of movement

Sub-terminal mouth

a mouth located on the underside of the head

Dorsal Fin

an unpaired fin on the back of a fish or whale, e.g., the tall triangular fin of a shark or killer whale.