Pb2+和Cd2+对水螅毒性作用的初步研究

应用镉、铅两种重金属离子对水螅进行急性和慢性毒性实验. 急性毒性实验结果显示,Cd2 96h的半致死浓度为1.81mg/L, Pb2 96h的半致死浓度为10.13mg/L.表明Cd2 和Pb2 均对水螅有毒害作用,且Cd2 的毒性强度大于Pb2 .慢性毒性实验结果显示,随着水螅在含两种重金属离子培养液中世代数的增加,水螅的世代时间有明显延长的趋势;此外,Cd2 为0.0025mg/L时,Pb2 为0.015625mg/L和0.0625mg/L时,水螅的世代时间显著大于对照组的值.表明较低浓度的重金属离子可能对水螅的生长繁殖有促进或刺激作用.

PRELIMINARY STUDIES ON TOXICITY OF Cd2+ AND Pb2+ TO HYDRA PSEUDOLIGACTIS

The acute and chronic toxicity of Cd~(2+) and Pb~(2+) to Hydra pseudoligactis were studied in this paper.The result of acute toxicity experiment showed that the 96h lethal concentration(LC_(50)) of Cd~(2+) was 1.81mg/L,and the 96h LC_(50) of Pb~(2+) was 10.13mg/L.Cd~(2+) and Pb~(2+) were both poisonous to this animal and the former's toxicity was severer than the latter's.The result of chronic toxicity experiment showed that the generation time obviously prolonged when the generation number increased in the cultivating liquids containing the two ions.Moreover,the generation time of this coelenterate animal was much longer than the comparison group's when the concentration of Cd~(2+) was 0.0025mg/L,or the concentration of Pb~(2+) is 0.015625mg/L and 0.0625mg/L,suggesting the two ions in lower concentrations may promote or stimulate the growth and reproduction of Hydra pseudoligactis.