Meeting Abstract

S1-1.13  Jan. 4  Locomotive fin function of brief squid Lolliguncula brevis STEWART, W.J.*; BARTOL, I.K.; Old Dominion University, Norfolk, VA; Old Dominion University, Norfolk, VA

Although the pulsed jet is the foundation of a squid’s locomotive system, the lateral fins also play an important role in swimming, potentially providing thrust, lift, and dynamic stability. Fin morphology and fin movement vary greatly among squid species, but direct data on the locomotive forces produced by complex fin motions are lacking. To begin to elucidate the locomotive role of the fins in squids, we examined fin dynamics and kinematics in the brief squid Lolliguncula brevis using digital particle image velocimetry (DPIV) and high-speed videography, respectively. During experimental runs, L. brevis swam freely against currents in a water tunnel, while a motorized traverse system was used to move the laser sheet and/or three cameras to keep pace with movements of the squid. Fin amplitude, beat frequency, and undulatory motions generally decreased with swimming speed, with the fins serving primarily as stabilizers at the highest speeds. Preliminary DPIV data indicate that both lift and thrust are produced by the fins, especially at low speeds, and vortex features generated during upstrokes and downstrokes correlate closely with swimming speed.