Fig. 5.

Locomotion through different environments is associated with distinct muscle output in C. elegans (A). Representative images of C. elegans crawling on solid surfaces, swimming in liquid, and burrowing through media, adopting characteristic “S,” “C,” and “W” shapes, respectively. (B) Neck curvature plots for crawling, swimming, and burrowing worms illustrating that burrowing consists of low-frequency, high-amplitude movements, whereas swimming relies on high-frequency, low-amplitude movements. (C) Each behavior has characteristic velocity ranges. (D) Movement amplitudes differ between behaviors and across the length of the animals. Animals crawled using large head flexions that did not propagate fully to their tail. (E) The contribution of the tail muscles to locomotion was greater during swimming and burrowing than during crawling. (F) The anterior bias in propulsion for all behaviors, as well as the increasing contribution of posterior musculature during swimming and burrowing, is reflected by muscular calcium transients. Heat maps show variations in cytosolic calcium in body-wall musculature inferred from GCaMP2 fluorescence (driven by the myo-3 promoter). (G) Quantification of calcium transients for different areas of the body during crawling, swimming, and burrowing. Although slower, burrowing produced the greatest calcium transients across the entire body of the worm. **P < 0.001, *P < 0.05.