Effects of Food Concentration, Animal Interactions, and Water Volume on Survival, Growth, and Reproduction of

The purpose of this study is to evaluate the effects of food concentration, animal interaction, and water volume on the survival, growth, and reproduction of Daphnia magna under flow-through conditions. A response surface design was used to determine the interactive, as well as the individual, effects of the three factors. The results indicated that there were no important interactive effects of the three factors on survival, growth, or reproduction of D. magna. Individual effects of the factors on reproduction were observed. Food concentration produced a linear trend, with increasing food concentration resulting in an increase in offspring production. The number of daphnids per container produced a quadratic trend, with the maximum offspring production occurring in vessels containing approximately 14 daphnids. Water volume produced a slight linear trend, with increasing water volume resulting in an increase in offspring production.