Fig. 7. Backing maneuver. Muscle activity is shown for the left supracarinalis (SC), hypochordal longitudinalis (HL), flexor dorsalis (FD), interradialis (IR) designated by its number (6, 9, 12) of dorsally corresponding fin ray, flexor ventralis (FV) and infracarinalis (IC) and right red axial myomere of the caudal peduncle (RED). Arrows indicate the dorsal progression of the wave along the distal edge of the caudal fin. Tail outlines closely follow the distal margin of the caudal fin and fin ray position. Bar (yellow), 2 cm.