Caudal fin

A fin-like structure at the rear of an aquatic animal's body. It generates thrust for swimming and varies in shape across animal groups.

Fish locomotion: The ways fishes move through water using body undulations and fin movements. The caudal fin supplies much of the thrust in many fishes.
Homocercal tail: A fish tail whose external lobes are roughly symmetrical, with the vertebral column ending near their base. This common caudal-fin form appears externally balanced despite internal asymmetry.
Thunniform locomotion: A swimming mode in which thrust comes mainly from a narrow tail stalk and crescent-shaped caudal fin. Tunas use this tail-driven mode for sustained, high-speed swimming.
Lunated tail: A crescent-shaped caudal fin with narrow lobes, common in fast-swimming fishes. Its streamlined outline contrasts with rounded tails suited to maneuverability.
Thrust: A force that propels an object forward, produced by accelerating surrounding fluid or expelled mass. A caudal fin pushes water backward to propel its owner forward.
Heterocercal tail: A fish tail with unequal upper and lower lobes and a vertebral column extending into the larger lobe. Its unequal lobes and skeletal support contrast with the homocercal arrangement.
Carangiform locomotion: A swimming mode in which body undulation is concentrated toward the rear, including the caudal fin. Many fishes with forked tails use this intermediate body-and-tail propulsion pattern.
Truncate tail: A caudal fin with a nearly straight rear edge and a broad, squared outline. This shape differs from the deeply forked tails of sustained swimmers.
Hydrodynamics: The study of how liquids move and exert forces on objects. Water flow around the fin determines its lift, drag, and thrust.
Diphycercal tail: A tail in which the vertebral column runs straight to the tip and the fin is arranged around it. It is a distinct caudal-fin structure found in some fishes.

Linked from 27 pages