[Coordination of the movement of the tube feet and arms of ophiurae during locomotion].

A role of the tube feet is considered for locomotion of ophiura Amphipholis kochii. During stepping, a tube foot sticks to the ground at its front position, and comes unstuck at the end of the step when reaching a certain hind position (relatively the direction of locomotion). Such an organization of the tubefoot mechanisms of stepping simplifies considerably the cooridination of tube feet and arms movements. The tube feet stick to the ground automatically when the arm on which they are located performs motor functions and push or pull the ophiura forwards; on the contrary, the tube feet come unstuck automatically when their arm moves forwards. Thus, the central nervous system is likely not to participate in the coordination of the tube feet and arms movements. It only determines the common direction of stepping for all tube feet, whereas the coordination between the tube feet and arms is achieved because of special properties of the tube feet stepping mechanisms.