Translations:Adventist Youth Honors Answer Book/Nature/Fishes/28/en

Lampanyctodes hectoris
(1) - operculum (gill cover), (2) - lateral line, (3) - dorsal fin, (4) - adipose fin, (5) - caudal peduncle, (6) - caudal fin, (7) - anal fin, (8) - photophores, (9) - pelvic fins (paired), (10) - pectoral fins (paired)

a. Dorsal fin

A dorsal fin is a fin located on the backs of fishes, whales, dolphins and porpoises, as well as the (extinct) ichthyosaurs. Its main purpose is to stabilize the animal against rolling and assist in sudden turns. Some animals have developed dorsal fins with protective functions, such as spines or venom. Many catfish can lock the leading ray of the dorsal fin in an extended position to discourage predation or to wedge themselves into a crevice. Dorsal fins come in a variety of shapes and sizes.