Fig. 7. Sinusoidal paths described by the soft dorsal fin and dorsal lobe of the tail within the horizontal plane (Fig.2D, position 2) during steady swimming at 1.1Ls-1, where L is total body length. Flow fields generated separately by each fin are illustrated in Fig.4 and Fig.8. Vortices shed by the trailing edge of the soft dorsal fin are represented schematically, but are located in positions determined by analysis of DPIV videos. By virtue of phase-delayed motion and a larger sweep amplitude (Fig.6), the caudal fin is positioned to intercept wake vortices generated by the dorsal fin.
