Effects of lindane on the predator-prey interaction between Hydra oligactis Pallas and Daphnia magna Strauss

Abstract

Laboratory tests were developed to allow identification of the effects of toxicants on the predator-prey interaction between Hydra oligactis Pallas and Daphnia magna Strauss. Three test methods, which differed with respect to initial Daphnia population, test period, and management of predation level, were used to determine the influence of the organochlorine insecticide lindane on the interaction. The criteria examined were the population structures of the two species. The lindane treatments did not alter the production of Hydra. However, the final population structure of Daphnia was variously affected by the toxicant in the different test systems. The most sensitive endpoint, with a lowest observed effect concentration of 4 μg/L lindane determined after a 14 day exposure period, was increased recruitment of juvenile Daphnia in a test system which incorporated management of the Hydra. The results are compared to previously reported data derived from single species chronic tests, and the suitability of the test methods for hazard evaluation is discussed.