SZYMIK, Brett G*; SATTERLIE, Richard A; Arizona State University; University of North Carolina at Wilmington: The Kinematics of Pteropod (Clione limacina) Swimming from Tethered and Freely Swimming Animals

Pteropod mollusks swim with the use of their wing-like parapodia, which are highly modified foot structures that serve as hydrofoils. Rhythmically flapping these parapodial “wings” serves to propel the animals through the water. Clione limacina swims in this manner. It orients its body vertically in the water column and uses dorsal-ventral wingstrokes to effectively hover in the water. The neural control of Clione‘s locomotory behavior has been studied in depth; much is known of the central pattern generator controlling Clione‘s wingbeat rate at both the cellular and neural network level. Our interest now extends downstream: how does the wingbeat rate set by the central pattern generator get turned into meaningful behavior? How are highly flexible hydrofoils controlled from a neural standpoint? In addressing these broad questions, we have started by quantifying the behavior itself. We have used multiple high-speed cameras for videogrammetry, and by manually digitizing Clione‘s movement, we have obtained three-dimensional kinematic data of Clione‘s swimming behavior. We previously presented data taken from tethered animals, a technique that aided filming and allowed us to collect data from animals swimming over a range of speeds. Here we present data from freely swimming animals for comparison against our data from tethered animals.