SZYMIK, Brett G; SATTERLIE, Richard A; Arizona State University; Arizona State University: High speed video analysis of Clione limacina swimming

The pteropod mollusk Clione limacina swims with alternate dorsal and ventral flexions of its wing-shaped parapodia. By this means of underwater flight, Clione “hovers” in the water column despite being negatively buoyant. As an introduction to a biomechanical study of Clione‘s swimming, we describe both a means of tethering swimming Clione and a means of marking Clione wings for reliable tracking of wing movements using video capture. High-speed videography (125 FPS) was used to capture images of tethered, marked Clione swimming. Angle of attack for both upswing (dorsal) and downswing (ventral) strokes of fast-swimming Clione was measured from still frames of the video. Data taken from four animals showed a mean downstroke angle of attack of 53.2&deg, while mean upstroke angle of attack was 53.0&deg during fast-swimming.