The purpose of the test is to assess the effect of substances on the reproductive output of Daphnia magna. Daphnids are small crustaceans that belong to the zooplankton and play an important role as filtering organisms in aquatic ecosystems of stagnant waters. They are particular convenient test organisms for long-term studies due to their short reproductive time and their asexual reproduction. The Daphnia magna Reproduction Test is one of the most important aquatic tests for the determination of chronic effects caused by test substances.
Young daphnids, aged less than 24 h at the start of the test, are exposed to a dilution series of the test substance for three weeks. At least three times a week the test medium is renewed. During the test duration of 21 days (two to three generation cycles), the surviving parent animals and the number of living offsprings produced are determined. As test result, the concentration, at which 50% of the number of offspring are produced compared to the control (EC50) and the lowest observed effect concentration (LOEC) as well as no observed effect concentration (NOEC) are calculated.
Major endpoints are the reproduction rate and the survival rate of the parental animals. In addition, the production of first brood, number of aborted broods, length of parent animals, presence of male neonates or ephippia and intrinsic rate of population increase are reported.