Pelvic fin characteristics?

Pelvic fin characteristics?

• A. A single fin on the back; provides propulsion.
• B. A pair of fins on the underside; aids stability and maneuverability.
• C. A fin behind the anal fin; helps balance.
• D. A fin on the side used for steering.

Answer: (B)

Pelvic fins are the pair of fins located on the underside of the fish near the belly. They provide stability and help with maneuverability, especially at slow speeds—allowing precise turns, balance, and controlled depth adjustments. They work together with the tail and pectoral fins to steer and maintain attitude, rather than primarily generating forward propulsion.

A single fin on the back is the dorsal fin, which mainly aids stability along the vertical plane. A fin behind the anal fin would be misplaced for pelvic fins, which are in front of the anal fin. A fin on the side used for steering describes the pectoral fins, the primary side steering and lift devices.