carangiform

Carangiform locomotion is a mode of swimming used by many teleost fishes in which propulsion comes mainly from the posterior portion of the body and the tail. In this mode the anterior body remains relatively stiff during swimming, and undulations are concentrated in the rear part of the body, especially near the caudal fin. This contrasts with more extensive body bending seen in anguilliform locomotion and with the highly restricted body movement characteristic of thunniform swimming.

In carangiform propulsion, a traveling wave moves along the body, with small amplitudes near the head that increase toward the tail. The caudal fin generates most thrust, while the pectoral, dorsal, and anal fins provide stability, steering, and braking as needed. The although undulation is focused posteriorly, the exact pattern can vary with speed and maneuvering demands. This mode is efficient at moderate to high swimming speeds and supports rapid cruising and burst locomotion.

Fishes commonly described as carangiform include members of the Carangidae family (such as jacks and trevallies) and many other pelagic teleosts. The carangiform style is well suited to streamlined, fast-moving bodies with strong, flexible tails. It is often viewed as an intermediate propulsion strategy, more flexible than thunniform swimming but more tail-driven than anguilliform locomotion, balancing efficiency and speed across a range of swimming conditions.

Overall, carangiform locomotion represents a key adaptation for efficient high-speed swimming in a broad group of pelagic fishes, enabling quick pursuit and sustained cruising in open-water habitats.