Fig. 5. Representative flow fields near the dorsal and anal fins during steady swimming. Yellow arrows indicate flow velocity; colored contours show vorticity. Schematic diagrams above the plots indicate the approximate position and orientation of the light sheets. (A) Flow in a transverse plane near the posterior edges of the dorsal and anal fins of bluegill sunfish swimming at 1.2 L s^–1. Vortices are shed along each dorsal and ventral edge of both the dorsal and anal fins. The caudal fin obscures some of the view (from Tytell, 2006). (B,C) Flow in horizontal planes at the level of the dorsal fin (B) and the anal fin (C) of trout swimming at 0.5 L s^–1. The pelvic fins are visible on the left side of both images, and C shows both the anal fin (center) and some of the of the caudal fin (right) (from Standen and Lauder, 2007). Scale bars throughout are 5 mm and scale vectors are 5 cm s^–1.