Meeting Abstract
Many fishes are unstable in roll. Staying upright thus requires constant coordinated input from multiple fins. To quantify how fish maintain roll stability, we developed a miniature device that produces a controlled jet of water. We sutured it on to bluegill sunfish (Lepomis macrochirus), so that they would receive a brief rolling perturbation during swimming at 3 speeds. We measured the kinematics associated with swimming before, during, and after the perturbation, and quantified the time it took the fish to recover. Before the perturbation, the pectoral fins we synchronized in phase or roughly 180 degrees out of phase, but did not coordinate with the caudal fin. The pectoral fin contralateral to the perturbing device was extended to dampen the roll and the fish was able to return to pre-perturbation swimming kinematics within 1.2 seconds at lower swimming speeds and within 0.9 seconds at higher swimming speeds.
