Dorsal fin
fin on the dorsal of fish and cetaceans
A dorsal fin is a fin on the back of most marine and freshwater vertebrates.
The main function of the fin is to stabilize the animal against rolling and to help sudden turns. There are some secondary functions: some fish have dorsal fins which produce venom at the tip, for example, the spiny dogfish.
Functions Edit
Some species have further adapted their dorsal fins to other uses.