The effect of temperature on the burst swimming performance of fish larvae

Newly hatched herring and plaice larvae were stimulated by probes to make C-start escape responses at temperatures between 5 and 15 °C. The responses and the subsequent burst-speed swimming were recorded and analysed using high-speed video at 400 frames s~'. The muscle contraction time of the initial C-start was temperature-dependent, ranging from 22-33 ms at 5°C to 17-21 ms at 15°C. Immediately following the C-start, tail-beat frequency ranged from 18s"1 at 5°C to 35 s~ ' at 15°C. Tail-beat amplitude, equivalent to 0.4-0.6 of a body length (L), and stride length, about 0.5 L, were not temperature-dependent. The escape speed ranged from 8Ls ~ ' at 5°C to 15 Ls " 1 at 15 °C. These results and those of other workers can be described by the equation: where/is tail-beat frequency, t is temperature and L is length