Abstract: The study on the acute,sublethal and chronic toxicity of 1,8-ihydroxyanthraquinone (1,8-dihAQ) to Daphnia magna showed that the 48 h LC50 was 0.37 mg·L^-1,and the feeding behavior of Daphnia magna was severely affected by the compound.When exposed to 0.2 mg·L^-1 of 1,8-dihAQ for 5 h,the filtration and ingestion rate of Daphnia magna was inhibited by 97%.Chronic toxicity test results indicated that the reproduction ability decreased dramatically after exposing to sublethal concentration of 1,8-dihAQ.It could be inferred that reproduction parameters and intrinsic rate of natural increase were the sensitive parameters in characterizing sublethal toxicity.The NOEC and LOEC values for reproduction parameters were also given.

Key words: Molecular microbial ecology, Molecular technique, Microbial ecology