SPAIN, Diara D. *; KIER, W.M.; UNC Chapel Hill; UNC Chapel Hill: Peristaltic Locomotion in Holothuroids (Echinodermata)

Although many vermiform soft-bodied invertebrates use a form of peristaltic locomotion, this mode of locomotion has not been widely studied. In particular, the kinematics of different forms of peristaltic locomotion have received little attention previously. Time-lapse videorecording was used to study peristaltic locomotion in four species of holothuroids: O. pygmaeus (Order Dendrochirotida), T. gemmata (Order Dendrochirotida), H. floridana (Order Aspidochirotida), and H. princeps(Order Aspidochirotida). Analysis of the recordings revealed that direct overlapping peristalsis is used by the dendrochirotid species and direct arching peristalsis is used by the aspidochirotid species. Measurements of the stride length and stride period were used to calculate stride and crawl velocities. The results indicate that stride and crawl velocities scale with body size. Supported by NASA grant NAG5-8759 and NSF grant IBN-972707 to W. M. Kier.