56.2 Thursday, Jan. 5 Gait selection in a pteropod mollusk? Examining the kinematics of Clione limacina's swimming for evidence of a gait change. SZYMIK, Brett G*; SATTERLIE, Richard A; Longwood University; University of North Carolina at Wilmington email@example.com
Discreet locomotory gaits have been defined in many ways, among them the energetic costs/savings of changing gait, the neural and muscular changes that affect limb coordination, and the kinematic changes associated with different locomotory speeds. Clione limacina is a pteropod mollusk that swims by flapping its parapodial wings. Clione demonstrates two distinct locomotory speeds: a near-constant slow swim speed that positions it in the water column and a fast swim speed used during escape and hunting behaviors. The neuromuscular patterns of Clione's swimming have been extensively studied. The neural control of slow swimming has been well characterized, as have the neural and muscular changes that bring about fast swimming. Here, we present results from a kinematic study of Clione's two swim speeds and consider our findings with respect to the literature of gait selection. We find that Clione may well present an example of a two-geared locomotory system wherein specific neural and muscular changes bring about a distinct increase in speed akin to a gait change, yet the phase-based kinematics of the swim speeds are remarkably similar.