中文摘要：

采用48h急性毒性试验研究了Pb2＋对多刺裸腹溞（Moina macrocopa）的48h-LC50值,采用生命表试验方法在0.5×106、1.0×106、2.0×106个细胞/mL的斜生栅藻（Scenedesmus obliquus）密度下研究了浓度为0.2、0.4、0.6、0.8、1.0mg/L的Pb2＋对多刺裸腹溞生命表统计学参数的影响。结果表明,Pb2＋对多刺裸腹溞48h-LC50值为10.5mg/L。与各食物密度下的对照组相比,除了0.5×106、1.0×106个细胞/mL下0.2mg/L的Pb2＋显著延长了多刺裸腹溞的生命期望,0.5×106个细胞/mL的食物密度下0.4mg/L的Pb2＋显著提高了多刺裸腹溞的净生殖率、0.40.8mg/L的Pb2＋显著提高了种群内禀增长率外,较高浓度的Pb2＋显著缩短了多刺裸腹溞的生命期望,降低了净生殖率、总生殖率和种群内禀增长率;且随着食物密度的升高,使净生殖率和总生殖率显著降低的Pb2＋浓度阈值呈降低的趋势,但使世代时间显著缩短的Pb2＋浓度阈值则呈升高的趋势。Pb2＋浓度、食物密度以及它们间的交互作用对多刺裸腹溞的各主要生命表统计学参数均有显著的影响（P〈0.05）。0.5×106、1.0×106cells/mL食物密度下,Pb2＋浓度与多刺裸腹溞的各主要生命表统计学参数间均有显著的剂量-效应关系;2.0×106cells/mL食物密度下,Pb2＋浓度与多刺裸腹溞的生命期望、总生殖率和净生殖率间均有显著的剂量-效应关系。多刺裸腹溞的生命期望、净生殖率和内禀增长率对Pb2＋污染的敏感性因食物密度的不同而存在着差异。

英文摘要：

The 48 h-LC50 of Pb2＋ to M.macrocopa was determined by an acute toxicity test,and the effects of different concentrations （0.2,0.4,0.6,0.8 and 1.0 mg/L） of Pb2＋ at three densities （0.5×106,1.0×106,2.0×106 cells/mL） of algae Scenedesmus obliquus on life table demography of M.macrocopa was studied by a life table experiment.The result showed that the 48 h-LC50 of Pb2 to M.macrocopa was 10.5 mg/L.Compared with the controls at every algal concentrations,except that Pb2＋ at 0.2 mg/L prolonged significantly the life expectancy at birth of M.macrocopa cultured at the algal densities of 0.5×106 and 1.0×106 cells/mL,and Pb2＋ at 0.4 mg/L increased the net reproductive rate and Pb2＋ at 0.4—0.8 mg/L increased the intrinsic rate of population growth of the animals cultured at the algal density of 0.5×106 cells/mL,Pb2＋ at higher concentrations shortened the life expectancy at birth,decreased the gross reproductive rate,the net reproductive rate and the intrinsic rate of population growth.With the rise of the algal density,the threshold of Pb2＋ concentration decreasing the gross reproductive rate and the net reproductive rate had a decline tendency,but the reverse was also true for that shortening the generation time.Pb2＋ concentration,algal density,and their interactions had significant effects on all the life table demography of M.macrocopa （P0.05）.When the algal densities were 0.5×106 and 1.0×106 cells/mL,there were significant dose-effect relationships between Pb2＋ concentration and each of all the life table demography.When the algal density was 2.0×106 cells/mL,there were dose-effect relationships between Pb2＋ concentration and the life expectancy at birth,the gross reproductive rate as well as the net reproductive rate.The life expectancy at birth,the net reproductive rate and the intrinsic rate of population increase of M.macrocopa had different sensitivities to Pb2＋ pollution with different food densities.