Thermal Tolerances of Common Cladocera

Thermal tolerances and fecundity over seven days at various temperatures were determined for Daphnia ambigua, Daphnia parvula, and Ceriodaphnia reticulata. Daphnia ambigua and D. parvula showed good survival at 30°c, but total mortality occurred within six days at 32°C for D. ambigua and at 33°C for D. parvula. Total mortality occurred within five days at 35°C for C. reticulata. Highest fecundity for all three species occurred at 25°C, followed by 30°C. Fecundity was reduced for all three test species above 30°C and was reduced for D. ambigua and D. parvula below 25°C.