Fig. 2

Wild-type animals rotate to align their direction of motion as they descend in solution. A–J 10 images collected at 1 image per second of a descending young adult, wild-type worm. The red dot indicates the position of the worm’s head. The animals are 6–12 mm beneath the water surface. The polar angle varies from 5.1° (frame A) to 141.5° (frame J). K The skeletons of the worm from A–J are depicted in colors corresponding to their angles of decent and shifted to align their geometric centers