EFFECTS OF FLUCTUATING TEMPERATURE ON DURATION OF EGG DEVELOPMENT OF CHYDORUS-SPHAERICUS (CLADOCERA, CRUSTACEA)

1. 1.|Duration of egg development of Chydorus sphaericus differed significantly under four temperature cycles, all of which averaged 20°C. 2. 2.|Duration of development was also significantly different among groups of C. sphaericus collected 9-12 days apart. 3. 3.|The Kaufmann effect adequately explains the observed differences in duration of egg development under the four different temperature cycles. 4. 4.|To predict duration of development in fluctuating temperatures, it is evidently more accurate to use the weighted average rate of development rather than the rate of development at the weighted averaged temperature. © 1979.