Peristaltic Motion of Centipedes in Confined Spaces

Centipedes navigate diverse and complex environments by propagating limb-stepping waves as well as waves of body bending. Some centipedes exhibit peristaltic motion within their burrows, described by Manton (1965) as an earthworm-like extension and contraction of body segments. However, centipede peristalsis has not been studied systematically. We studied peristaltic motion in two species: Scolopendra subspinipes and Scolopendra polymorpha (body lengths: 80mm – 145mm, body width 6mm – 10mm, mass: 3g – 10.5g), by developing a simplified model of a burrow that allowed us to quantify the body kinematics. We created a rigid channel with a fixed 15mm height and a width that could be varied in 2mm increments between 8mm and 20mm and used a funnel to direct the centipedes into the channel. Multiple trials were performed at each channel width with individual centipedes from each species (12 S. subspinipes and 5 S. polymorpha). We observed the behavior with a high-speed camera and tracked the kinematics via markers painted on each segment. As the width of the channel decreased, the centipedes switched from undulatory movement to peristalsis at a characteristic average body segment width to channel width ratio of approximately 0.5. We hypothesize that peristalsis enables locomotion in confined spaces which would otherwise restrict limbed locomotion. We will test this by creating a robophysical model in collaboration with Ground Control Robotics, Inc.