Fig. 4. An episode of swimming performed with a stable orientation of left side up, with a load attached to the back of the lamprey (shown as a white rectangle in A). (A,B) The side and top views in eight consecutive frames are analogous to those illustrated in Fig. 2. (C) The curvature plots for body configurations in the transverse plane for frames 2, 5 and 8 are presented and are analogous to the plots in Fig. 3E. R, right; L, left; D, dorsal; V, ventral sides of the body.