No, the fin is the formal name and the only name for the bottom fin of a fish.
The bottom fin of a fish is called the fin. It is located on the ventral (underside) surface of the fish, near the posterior end. The fin helps the fish maintain stability, control its movement, and navigate in the water. It works in conjunction with other fins, such as the dorsal fin and the caudal fin, to assist with balance and propulsion. If you ever need to know the names of different fish fins or other similar anatomical features, it's helpful to consult a fish anatomy diagram or a reliable marine biology resource.
