SHORT COMMUNICATION Effects of Microcystis aeruginosa exposure and nutritional status on the reproduction of Daphnia pulex

Abstract. Microcystis aeruginosa exposure, as well as low food availability before the experiment, resulted in decreased egg viability in Daphnia pulex Food availability during the experiment did not affect the results significantly Several laboratory studies have shown that the reproduction of cladoceran zooplankters can be inhibited by cyanobacterial exposure, either due to poor nutritional value of the cyanobacteria (e.g. Porter and Orcutt, 1980), or because of inhibited food uptake even in the presence of high-quality food (Lampert, 1981). Thus, the ability of cladocerans to collect enough energy and nutrients for reproduction in the presence of cyanobacteria is of importance in determining how successful reproduction will be. On the other hand, we hypothesize that inhibited reproduction may also be directly caused by cyanobacterial toxins, which may interfere with processes essential for the development of eggs and embryos to juveniles. We think that this assumption merits careful study, because if eggs that are formed in the brood chamber do not develop, the