A Comparison of Sensitivity on Chronic Effects of Daphnia magna and Ceriodaphnia dubia to Several Kinds of Organic Chemicals

The current worldwide regulatory guideline requires evaluation of the chronic effects of chemicals on water flea Daphnia magna. Based on the life cycle of D.magna, chronic tests with survival and reproductive endpoints requires a 21 days exposure period. Ceriodaphnia dubia, a common freshwater invertebrate similar to the D.magna, has a shorter life cycle and therefore reproductive (and survival) endpoints have been established following about 8 days of exposure. No observed effect concentrations for reproduction were obtained for D.magna and C.dubia following exposure to general 10 organic compounds (ie. aromatic amines as pharmaceutical, chlorinated aromatic compound, polyaromatic compound and alkyl ester) according to the OECD TG 211 and the biological test method of Environmental Canada. These data were evaluated to determine whether one organism might be considered more sensitive. Reproduction data obtained from C.dubia chronic test provide similar sensitivity to D.magna in this study. Based on these data, C.dubia may be used as a cost-effective alternative and representative invertebrate species when assessing the potential risk on the organic compounds.