Fig. 1. (A) Posterolateral view of a trout Kármán gaiting behind a D-cylinder with fine wire electromyography electrodes inserted into the red and white axial muscles along the body (see Materials and methods for details). A map of electrode insertion sites for superficial red (R) and deep white (W) axial muscles along four longitudinal locations of the body in ventral (B) and lateral (C) view are shown. From the snout, insertion sites 1–4 correspond to 0.23, 0.40, 0.56 and 0.73 L down the body from the snout, respectively, where L is total body length. s denotes the placement of a suture loop, used to hold individual electrode wires in place against the body. Asterisks (i.e. R1* and R3*) indicate electrodes inserted on the right side of the fish. The center of mass is represented by a gray circle.