Figure 11.

Coordination between peristaltic body contractions and sucker-mediated propulsion modulates the speed of movement under severe confinement. (a) Box plots of S. mansoni worm speeds (in a 100 µm gap) with a wave frequency of more than 0.3 Hz using exclusively peristaltic waves of body contractions (red, n = 8) or by coordinating sucker motion with peristaltic body waves (blue, n = 5). Asterisks denote statistically significant differences between medians (Mann–Whitney test, p-value < 0.01). (b) Scatter plot of movement speed versus frequency of peristaltic waves. Red circles, peristaltic waves only; blue squares, coordination between the suckers and peristaltic waves. Linear least-square fits through the origin are applied to each dataset. (c–e) Box plots of motility parameters for worms with wave frequency more than 0.3 Hz migrating exclusively by peristaltic waves of body contractions (red, n = 8) or by sucker–peristaltic wave coordination (blue, n = 5); (c) average wave frequency, (d) average wave speed and (e) average body length. (Online version in colour.)