Which fin is commonly referred to as the tail fin?

Which fin is commonly referred to as the tail fin?

• A. Pectoral fin.
• B. Anal fin.
• C. Operculum.
• D. Caudal fin.

Answer: (D)

In fish anatomy, the fin at the very end of the body is called the caudal fin, which is commonly known as the tail fin. This fin sits at the tail and provides most of the propulsion by pushing water backward as the fish swims. Other fins have different roles: pectoral fins are near the head and help with steering and lift; the anal fin is on the underside near the tail and aids stability; the operculum is the gill cover, not a fin. So the tail fin is the caudal fin.