Meeting Abstract
68.6 Thursday, Jan. 6 Kinematics of swimming in the manta ray (Manta birostris): 3D analysis of open water maneuverability FISH, F.E.*; NICHOLS, R.H.; DUDAS, M.A.; MOORED, K.W.; BART-SMITH, H.; West Chester Univ., Pennsylvania; West Chester Univ., Pennsylvania; Dudas’ Diving Duds, West Chester, Pennsylvania; Princeton Univ., New Jersey; Univ. of Virginia, Charlottesville ffish@wcupa.edu
The locomotor movements of the propulsive structures of marine vertebrates have been confined mainly to relatively small animals, which can be examined in laboratory or aquarium situations. Unrestrained swimming by large vertebrates is difficult to examine due to infrequent observations, size of the animal, and difficulty setting up video equipment in the proper orientation. To detail the kinematics of swimming by large manta rays, scaled video recordings (30 frames/s) of mantas were made in an open water environment around Yap, Micronesia. With divers on SCUBA, two video cameras in underwater housings and mounted on tripods were positioned on the bottom of a lagoon around a cleaning station at a depth of 24 m. Mantas were recorded singly or in pairs as they maneuvered about the cleaning station. The two video recordings were synchronized by periodic discharges of an underwater strobe and were analyzed using Proanalyst software in three dimensions. Mantas swam with an oscillatory, wing-like motion. Asymmetrical motions of the pectoral fins, including spanwise undulations, executed powered yawing turns. Gliding turns utilized 20-25o banking angles of the body with the pectoral fins held in a dihedral orientation. Upward pitching maneuvers were initiated by anterior bending of the body. As displayed from stereo-video of mantas in open water, these pelagic fish demonstrated high maneuverability that would have been considered uncharacteristic of such large animals.
