Fig. 11. Kinematics of continuous swimming in a final-stage larva. (A) Semi-schematic depiction of the path followed by the centre of gravity (dashed line) and the abdominal tip (continuous line) during two swimming cycles. The centre of gravity is assumed to lie at the junction between the thorax and the abdomen. The superimposed profiles represent the configuration of the body just after the half-way points in the cycle when the body is beginning to flex rapidly and the abdominal tip travels backwards with respect to the mean swimming path through the water. (B) The path of the centre of gravity (filled circles) and the abdominal tip (open circles) at 10ms intervals. (C) The forward velocity of the centre of gravity (filled circles) and the abdominal tip (open circles). The hatched areas in C represent the period when the abdominal tip is travelling backwards through the water relative to the mean forward swimming direction. The numerals in C are the velocities calculated from the corresponding intervals between points shown in B.