Meeting Abstract
Tomopterids are globally distributed, highly motile midwater polychaetes with an unusual body form. They have a gelatinous body with no internal separation of segments, large paddle-like lateral appendages (parapodia), and only a single pair of bristles (internal, acicula) at the anterior. These morphological differences distinguish tomopterids from all other polychaetes, and based on generalized models of polychaete swimming, suggest that tomopterids are slow swimmers incapable of sustained fast swimming. However, in situ observations from remotely operated vehicles (ROVs) indicate otherwise. We collected 13 tomopterids representing six species ranging in size from 1 to 10 cm (between 440 and 1083 m depths) using ROV Doc Ricketts, and transferred them to filming vessels on board R/V Western Flyer. Using high-speed video, and subsequent digitization of 52 features on each individual using DLTdv, we find that (1) swimming is accomplished using a combination of metachronal paddling of parapodia and the propagation of an anteriorly directed body wave, and (2) paddling uses a combination of sinusoidal and sequential rowing behaviors to maximize the difference between thrust and drag during power and recovery strokes. Our results provide valuable insight into kinematics of tomopterid worms with potential applications for soft robotics and bio-inspired design.
