The study on the acute,sublethal and chronic toxicity of 1,8-dihydroxyanthraquinone （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.
