Abstract

The effects of eight different media on reproduction, condition and growth of Daphnia magna were measured in three consecutive generations. These media were: 1) ISO-medium, 2) ISO-medium + trace-elements, 3) ISO-medium + selenium + bromide, 4) Elendt-medium, 5) DSW + old rearing water, 6) DSW + trace-elements, 7) DSW + selenium + bromide and 8) DSW + enriched pond water. The design of the experiments was based on the EEC draft guideline "Prolonged toxicity study with Daphnia magna: Effects on reproduction." ISO medium and two modifications of ISO medium gave an unacceptable low reproduction together with a high mortality among newborn daphnias. The best results were produced by the medium consisting of DSW and enriched pond water.