The effects of temperature on “S‐Strike” feeding of larval herring,Clupea Harengus L.

Both Manx autumn‐spawning and Clyde spring‐spawning stocks of Atlantic herring were reared at a range of temperatures (Manx 10 and 13°C;Clyde 5, 8 and 12°C). The behaviour of larvae, feeding on Anemia nauplii at a range of test temperatures (7.0, 10.0 and 13.0°C for Manx and 6.8,9.3 and 13.0°C for Clyde herring) was recorded using a high speed video system at 200 frames per second. The maximum velocities of feeding ‘S‐strikes’ (measured during frame‐by‐frame analyses) were positively correlated with body length, capture time and attack distance. In contrast to burst swimming speeds reported elsewhere, strike velocities showed only a weak relationship with test temperature. Both strike behaviour and velocity altered as larvae developed and both were modified by rearing temperature.