中文摘要：

为了比较不同食物密度下污染物浓度对受试生物的慢性毒性,筛选出以轮虫为受试生物对水环境中Cd污染进行监测的敏感指标,研究了在不同斜生栅藻密度（1.0×106、3.0×106和5.0×106cells.ml-1）下不同浓度（2.5、5.0、10.0、20.0和40.0μg·L-1）Cd2＋对萼花臂尾轮虫生命表统计学参数的影响.结果表明：（25±1）℃下Cd2＋对轮虫的24hLC50为37.7μg·L-1.与各藻密度下的对照组相比,当藻密度为1.0×106cells.ml-1时,20.0和40.0μg·L-1的Cd2＋显著延长了轮虫的世代时间,5.0μg·L-1的Cd2＋显著提高了轮虫的后代混交率;当藻密度为3.0×106cells.ml-1时,除了5.0μg·L-1外,其他浓度的Cd2＋显著降低了轮虫的后代混交率;而当藻密度为5.0×106cells.ml-1时,Cd2＋浓度对轮虫的所有生命表统计学参数均无显著影响（P〉0.05）.藻密度对轮虫的世代时间、生命期望、净生殖率和后代混交率均有显著影响（P〈0.05）,Cd2＋浓度对轮虫的世代时间和后代混交率有显著影响（P〈0.05）,两者交互作用对后代混交率有极显著影响（P〈0.01）.轮虫的世代时间和后代混交率是在1.0×106和3.0×106cells.ml-1食物密度下对Cd2＋污染比较敏感的参数,其中后代混交率最敏感.

英文摘要：

In order to understand the chronic toxicity of a pollutant to an organism in an aquatic environment with different food density,and screen out sensitive endpoints for monitoring Cd2＋ pollution with rotifers as test animals,this paper studied the effects of different concentration （2.5,5.0,10.0,20.0 and 40.0 μg·L-1） Cd2＋ on the life table demography of Bracionus calyciflorus at the Scenedesmus obliquus density being 1.0×106,3.0×106,and 5.0×106 cells·ml-1. The results showed that at 25±1 ℃,the 24 h LC50 of Cd2＋ to B. calyciflorus was 37.7 μg·L-1. Compared with the controls at the same food density,when the S. obliquus density was 1.0×106 cells·ml-1,20.0 and 40.0 μg·L-1 of Cd2＋ prolonged the generation time of B. calyciflorus significantly,and 5.0 μg·L-1 of Cd2＋ increased the percentage of B. calyciflorus mictic offspring. When the S. obliquus density was 3.0×106 cells·ml-1,the Cd2＋ at all test concentrations except 5.0 μg·L-1 decreased the percentage of mictic offspring; when the S. obliquus density was 5.0×106 cells·ml-1,all test concentration Cd2＋ had no effects on the life table demography （P0.05）. S. obliquus density had significant effects on the generation time,life expectancy at birth,net reproduction rate,percentage of mictic offspring of B. calyciflorus （P0.05）,Cd2＋ concentration had significant effects on the generation time and the percentage of mictic offspring （P0.05）,and the interaction of S. obliquus density and Cd2＋ concentration had significant effects on the percentage of mictic offspring （P0.01）. Among all the studied parameters,the generation time and the percentage of mictic offspring were more sensitive to Cd2＋ pollution under the algal densities of 1.0×106 and 3.0 ×106 cells·ml-1,with the latter being the most sensitive.