Comparative sensitivity of the several zooplankton species (Cladocera, Copepoda) to sumicidine-alpha insecticide

The sensitivity of seven zooplankton species ( Daphnia magna, D. longispina, D. pulex, Simocephalus vetulus, Scapholeberis mucronata, Eudiaptomus graciloides , and Cyclops strenuus ) to an insecticide, sumicidine alpha was studied. LD 50 values upon a 24-hour exposure were determined. Daphnia pulex and D. longispina turned out to be highly susceptible to the insecticide, while the individuals representing the natural population of D. magna happened to be the most resistant. The data on sensitivity distribution among different zooplankton species are provided, as well as the concentrations potentially hazardous for 5% and 50% of the population are calculated.