Synergistic mechanisms of dorsal and anal fins in the C-turn maneuvers of zebrafish.

This article focuses on the hydrodynamic role of dorsal and anal fins in zebrafish during C-turn maneuvers, using a three-dimensional geometric model and self-propulsion computational simulations based on experimental data. The study finds that these fins enhance propulsion by suppressing lateral flow and strengthening vortex structures—specifically posterior body vortices (PBVs) that amplify leading-edge vortices (LEVs) on the caudal fin—resulting in increased velocities during turning, particularly at small angles. Additionally, the dorsal and anal fins improve maneuvering stability by generating opposing lateral forces that reduce angular velocity fluctuations, enabling smoother and more controlled turns. These findings provide insights into the adaptive significance of fin morphology in fish locomotion and suggest potential applications for improving maneuverability in autonomous underwater vehicles through biomimetic fin coordination.