Meeting Abstract
Tomopterids are a family of highly-derived, holopelagic, gelatinous polychaetes found throughout the world’s oceans. The lack of internal segmentation and chaetae combined with their large paddle-like appendages (parapodia) distinguish tomopterids from other polychaetes. Paddling of the fleshy parapodia and lateral body motion allow these animals to swim with a speed and maneuverability that are visually distinct from other swimming polychaetes, such as nereids. We captured living tomopterids using remotely operated vehicles in California’s Monterey Bay and transferred them to filming vessels onboard the ship. Swimming motion (kinematics) of the animals was studied using high-speed video recordings of the animals. We found that active paddling of the parapodia generates forward thrust, augmenting the thrust derived from the forward-directed body wave during straight, forward-directed swimming. In addition, this body wave allows for increased range of motion of the parapodia, resulting in an increased displacement of the body per stroke. The characteristics of the stroke deviate from existing metachronal simplified models for polychaetes and crustaceans alike, and a drag/thrust model is presented based on a simplified Tomopteris body plan. These results could have applications in biomimetics and soft robotics.
