Egg incubation at temperatures below 5 °C resulted in strongly reduced larval hatching success (Fig. 1). Larval hatch success after incubation at 5 °C was not significantly affected by exposure length (F(1,8) = 0.02, P = 0.9). Exponential or logistic curves were fitted to the datasets for 0 °C, -5 °C and -9 °C, which showed an exposure length-dependent trend. The curves are best described by the functions:Fig. 1Larval hatch success of eggs exposed to 5 °C, 0 °C, -5 °C and -9 °C for up to 14 days. Hatch success represents the cumulative proportion of hatched larvae counted at three consecutive days after hatch stimulus