What is the tail fin of a fish called?

What is the tail fin of a fish called? The tail fin is called the caudal fin.

“Caudal” comes from the Latin word cauda, meaning “tail.” The caudal fin is attached at the rear of the caudal peduncle, the narrowed section connecting a fish’s body to its tail. In many fish, it supplies much of the thrust used to move forward through the water.

Caudal fins come in several structural and visual forms. Most modern bony fish have homocercal tails, which look broadly symmetrical even though the vertebral column extends slightly into the upper lobe. Sharks and many other cartilaginous fish have heterocercal tails, with the backbone extending into a usually larger upper lobe.

The caudal fin is easy to confuse with the dorsal fin. The dorsal fin sits along the back and mainly helps stabilize the fish against rolling, while the caudal fin is the rear fin associated with propulsion. Some fish, such as puffers and trunkfish, rely less on the tail and use other fins for movement.