Fins
Salmon have eight fins including the tail. They are made up of a fan of bone-like spines with a thin skin stretched between them. The fins are embedded in the salmon’s muscle, not linked to other bones, as limbs are in people. This gives them a great deal of flexibility and maneuverability.
Each fin has a different function. The caudal or tail, is the largest and most powerful. It pushes from side to side and moves the fish forward in a wavy path.
The dorsal fin acts like a keel on a ship. It keeps the fish upright, and it also controls the direction the fish moves in.
The anal fin also helps keep the fish stable and upright.
The pectoral and pelvic fins are fused for steering and for balance. They can also move the fish up and down in the water.
The adipose fin has no known function. It is sometimes clipped off in hatchery fish to help identify the fish when they return or are caught.