Glossary of fish terms

A

Abdomen

The belly of the fish containing the internal organs.

Adipose fin

Small fleshy fin-like projection on the back of some fishes between the dorsal fin and the caudal fin (tail).

Anal fin

Fin on the belly behind the anus.

Antennae

Paired feelers on the head of crustaceans.

Anterior

Towards the head or front.

Anus

External opening to the intestine.

B

Barbels

Fleshy whisker-like extensions, usually under the mouth.

Benthic

Living close to or on the bottom.

By-catch

All catch other than the species sought (non-target species).

C

Canine teeth

Conical fang-like teeth on the jaws.

Carapace

Shell or exoskeleton encasing the body of a crustacean.

Carnivorous

Feeding or preying upon animals - flesh eating.

Cartilage

A substance more flexible than bone, but serving a similar structural purpose.

Caudal peduncle

The base of the tail between the anal fin and the caudal fin.

Cheek cleft

Cleft on gill cover.

Crustacean

Shellfish, e.g. prawns, crayfish, crabs, yabbies.

D

Demersal

Living on or near the sea bottom.

Dimorphic

Body shape and colour varies between the sexes.

Diurnal

Active during daylight.

Dorsal fin

Fins that run along the back of a fish (except an adipose fin).

E

Elongate

Extended in length.

Estuarine

Living in estuaries, the tidal reaches of rivers.

F

Fillet

Slab of flesh cut from the side of a fish.

Finlets

Series of separate small fins arranged along the back and belly usually between the dorsal fin and tail and/or anal fin tail.

G

Gill arch

Bony or cartilaginous structure supporting the gills.

Gills

The feathery organs by which fish extract oxygen from the water.

H

Herbivorous

Feeding on vegetable matter - plant eating.

I

Ike jime

Method of killing fish by inserting a sharp spike into their brain.

K

Keel

Hard ridge along the body usually on the head or caudal peduncle.

L

Lateral line

Sensory canal system, usually consisting of specialised scales, that runs along the sides of all fish. It is more visible in some fish than in others.

M

Molar

Blunt tooth used for crushing and grinding.

Mollusc

Shellfish such as oyster, scallops, squid, octopus, etc.

Mucus

Slimy substance secreted by mucus glands. Used by fish to protect their skin from disease, parasites and injury.

N

Nape

Neck region adjacent to skull.

Nocturnal

Active at night.

O

Ocellus

Round marking that mimics or simulates an eye.

Omnivore

Feeding on both animals and plants.

P

Paired fins

Pectoral and pelvic fins.

Pelagic

Living in the open ocean or sea above the sea floor.

Pelvic

Paired fins on the belly before the anal fin.

Planktivore

Feeding on plankton.

Plankton

Tiny plant and animal life adrift in the water column.

Posterior

Towards the tail or rear.

R

Rostrum

Beak-like extension on the carapace of some crustaceans.

S

Scutes

Modified spiny scales that form hard plates along the tails of some fish.

Shellfish

General term for crustaceans and molluscs.

Soft dorsal fin

Dorsal fin supported by flexible rays rather than rigid spines.

Spinous dorsal fin

Dorsal fin supported by rigid spines.

Swim bladder

Sac-like organ in fish's abdomen containing air - air bladder.

T

Terminal

Located at the end of something.

U

Uniform colour

Having only one colour.

V

Ventral

Of or pertaining to the underside.

Further information

Last updated 18 March 2010