Coordination of arm movement during locomotion in Ophiuroidea

Ophiura Amphipholis kochii Lütken can move with any one of five arms directed forwards; therefore, each arm performs various functions during locomotion. The arm amputated together with the adjoining part of the central nervous ring is capable of complicated behaviour, particularly, of locomotion. Transection of the central nervous ring results in disturbances of the arms coordination. Experiments with amputation of a part of the arms showed that afferent signals from arms are important for determination of the leading arm and mode of locomotion. The experimental data suggest that each arm has an autonomous nervous centre, and coordinated activity of all arms is acheaved by an interaction of the nervous centres. The interaction results in function distribution among the arms and in synchronization of arm movements. The leading arm prevails, since the influences exerting by its centre determine activity of adjacent centres.