Fig. 8 Kinematic and timing data for manoeuvres. (A) Representative example of a single manoeuvre. The thick blue line represents the change in lateral body position (left y-axis); the blue dots on the line represent the starting position, the maximum body excursion to the outside of the turn, the maximum body excursion to the inside of the turn and the final body position. Three alternate final body positions are displayed with solid, dashed and dotted lines. Each manoeuvre is divided according to body excursion: stage one (green) is the start of the manoeuvre until the maximum excursion to the outside; stage two (yellow) is the maximum outside excursion to the maximum inside excursion; and stage three (pink) is the maximum inside excursion until the final body position. The black line represents heading over time (right y-axis). The timing of original heading (o), the start and end of maximum heading (ms and me, respectively), and the final heading (f) are noted by dashed vertical black lines. The diagram of fish below represents the general motion of the fish body at the time of original heading, the maximum heading start and end, and the final heading (f). (B,C) Polar plots of mean timing for all manoeuvres color coded to the three stages of the manoeuvre. Black bars represent the timing of heading changes and correspond with A. Only variables with directionality (Raleigh's test P<0.05) are represented on the polar plots. Small dots represent minimum/abduction mean values and large dots represent maximum/adduction mean values. (B) The outside fin had directionality in fin area (green), and fin abduction with fish transverse (blue) and flow transverse (red) planes. (C) The inside fin had directionality in fin area (green), and both fin abduction and adduction with fish transverse (blue) and flow transverse (red) planes. All variables that had consistent timing peaked well after the fish had started turning, suggesting that pelvic fins are not used to initiate manoeuvres but possibly to stabilize and control body position while returning it to a forward heading.