Dorsal fin

Wildlife biologists often use the distinctive nicks and wear patterns which develop on the dorsal fins of whales to identify individuals in the field.

In anglerfish, the anterior of the dorsal fin is modified into a biological equivalent to a fishing pole and a lure known as an illicium or esca.

Like tuna, mackerel and other scombroids, billfish streamline themselves by retracting their dorsal fins into a groove in their body when they swim.

[4][5] The great white shark's dorsal fin contains stabilizing dermal fibers that stiffen dynamically as it swims faster, helping it to control roll and yaw.

[8] The muscles contract and pull against the basals of the pterygiophores along one side of the body, which helps the fish move through water by providing greater stability.