Meeting Abstract
Sea stars walk through the coordinated action of hundreds of tube feet despite lacking a central nervous system. We investigated the neuromechanics of walking in sea stars through a combination of experimentation and mathematical modeling. We devised software to automatically track the motion of the tube feet from video recordings. Kinematic measurements of Protoreaster nodosus showed that the tube feet moved with a power stroke in the opposite direction of walking, with no significant differences between arms. We found that the coordination among the tube feet was the highest when sea stars transitioned into the faster bouncing gait. Our mathematical model considered the mechanics of the body and tube feet and assumed that each foot operates independently with a chain of reflexes. Simulations successfully replicated both slow crawling and bouncing gaits. These results suggest that the tube feet synchronize by using local proprioception at the tube feet rather than global neuronal signals.
