Fecundity and Longevity of Ceriodaphnia Dubia/affinis in Relation to Diet at Two Different Temperatures

Abstract

The purpose of this study was to develop a successful culturing system for C. dubia and C. affinis. Algal foods [17] were offered to C. dubia/C. affinis; their effect on fertility and longevity was observed. The best single algal food of these 17, in terms of neonate production, was Ankistrodesmus convolutus cultured in an inorganic defined medium supplemented with crystalline B12, biotin and thaimine. This green alga is cultured and fed to C. dubia/C. afffinis axenically; the zooplankton are maintained on sterile culture although the animals themselves are not bacteria-free. Demographic data obtained from individual animals reared at 20.degree. C and at 24.degree. C showed that reproductive frequency is greater at 24.degree. C than at 20.degree. C, but the mean brood size is somewhat larger at the lower temperature. Longevity studies showed that animals survived longer perids at the lower temperature. One female lived 125 days and during that time produced 29 broods. Starvation data confirmed the success of the experimental diet, in that neonates carried sufficient lipids from their mothers, survived and matured to reproduce in the absence of food for .apprx. 8 days. A successful batch culturing system is described.