Meeting Abstract
Fishes regularly encounter unsteady and turbulent flows. These flows can perturb steady swimming and require the fish to make corrections in order to return to an unperturbed, stable swimming state. A fish’s ability to return to steady state swimming after a disturbance is critical to swimming effectively. As such, the ability to stabilize can influence a fish’s success in obtaining food, migrating, or avoiding predators. In terrestrial systems, locomotor stability has been studied by introducing an acute perturbation into an otherwise steady system. Here, we use the same concept to study stability in aquatic locomotion. We developed a miniature device that produced a brief jet of fluid of a known impulse. We then sutured the device to the dorso-lateral surface of bluegill sunfish (Lepomis macrochirus), just above the center of mass. We then perturbed the fish at different phases during its swimming motion and at different swimming speeds. We quantified the initial effect of the perturbation, which can cause rolling or lateral motion. After the perturbation, fish made small kinematic adjustments, but did not startle or perform dramatically different behaviors. The time it took the fish to return to steady swimming after the perturbation is used as a measure of stability.
