Figure 6

Kinematics during vertical backward crawling. (a) Sequential images of a backward crawling cycle. (b) Schematic diagram of fin states. Unfilled squares represent adduction, red squares indicate abduction, and half-red squares indicate a transitional state. (c) Sequential tracings of the midline from the head (blue diamond) to the tail (blue inverted triangle) through one complete crawling cycle. (d) Axial displacement. (e) Axial velocity. (f) Girdle muscle length. (g) Girdle muscle contraction rate.