In addition to the main fins, there may be additional fins on the body of fish. These include the adipose fin (pinnaadiposa) located behind the dorsal fin above the anal fin, which is a skin fold without rays. It is characteristic of fish of the families Salmonids, Smelt, Grayling, Haracinids and some Catfishes. On the caudal stem in a number of fast-floating fish behind the dorsal and anal fins are often small fins consisting of several rays. In mackerel between the dorsal and caudal fins is a number of smaller fins (4 to 10), helping to avoid the formation of whirlpools during rapid movement.

Additive fins are the numerous fins of mackerel fish behind the two dorsal and anal fins. They act as vortex dampeners, which helps to increase the swimming speed of the fish.