Fig. 3. Angle of attack of the tail. Shades from white to red represent increasing swimming speeds. (A) Angle of attack plotted against tail velocity over complete tail beats. Different shaped markers represent different individuals. (B) Fraction of the tail beat cycle in which the tail has a positive angle of attack plotted against swimming speed. Shades of blue and green represent different individuals. Boxes are standard statistical box plots, described in detail in Fig. 1.