No diapause prolongation response of Daphnia in the presence of planktivorous mosquitofish (Gambusia holbrooki)

Recent research suggests that planktonic organisms in resting stages can perceive predators chemically and delay hatching to evade predation. Using a co-occurring predator-prey pair (Gambusia holbrooki Girard and Daphnia curvirostris Eylmann) from a Mediterranean floodplain wetland, this study tested for such predator-avoidance behaviour of Daphnia. Results show that hatching patterns of Daphnia were not reduced by the presence of different biomass levels of Gambusia. This could be due to the fact that the density of Gambusia in the wetland is high from late spring to late autumn, suggesting that delayed hatchlings would face increased mortality through consumptive predation.