García-García Gerardo, Nandini S, Sarma S S S
Postgraduate Programme in Limnology and Marine Sciences, National Autonomous University of Mexico, Ciudad Universitaria, Circuito Universitario s/n, CP 04510, Mexico City, Mexico.
Ecotoxicology. 2006 Jul;15(5):425-36. doi: 10.1007/s10646-006-0064-6.
To test the hypothesis that sediment would have a synergistic effect on the toxicity of lead to cladocerans, we performed life table demography experiments with two pelagic (Diaphanosoma birgei and Moina micrura) and one littoral (Alona rectangula) cladoceran species. Life table demography experiments were conducted at three levels of turbidity (0, 17 and 170 NTU) and six concentrations of lead (as PbCl2) from 0 to 0.71 mg l(-1). Median lethal concentrations (LC50) forA. rectangula, D. birgei and M. micrura were 7.06 +/- 0.39, 3.16 +/- 0.25 and 3.24 +/- 0.69 mg l(-1) of Pb. Life table study showed that in general, the presence of sediments in test jars allowed an overall increase of 20-75% in both survivorship and reproduction of the cladoceran species exposed to different concentrations of Pb. At 0.04 mg l(-1) of Pb, the population growth rates were 0.127 forA. rectangula, 0.037 for D. birgei and 0.471 d(-1) for M. micrura in the absence of sediments but were elevated in their presence (0.309, 0.141 and 0.722 d(-1), respectively). The data have been discussed in relation to their importance in shallow, turbid Mexican waterbodies.
为了验证沉积物会对铅对枝角类动物的毒性产生协同作用这一假设，我们对两种浮游（透明溞和微型裸腹溞）和一种沿岸（矩形网纹溞）枝角类物种进行了生命表统计学实验。生命表统计学实验在三种浊度水平（0、17和170 NTU）以及六种铅浓度（以PbCl₂计）从0到0.71 mg l⁻¹的条件下进行。矩形网纹溞、透明溞和微型裸腹溞的半数致死浓度（LC50）分别为7.06 ± 0.39、3.16 ± 0.25和3.24 ± 0.69 mg l⁻¹的铅。生命表研究表明，总体而言，测试罐中存在沉积物时，暴露于不同浓度铅的枝角类物种的存活率和繁殖率总体提高了20 - 75%。在0.04 mg l⁻¹的铅浓度下，在没有沉积物的情况下，矩形网纹溞的种群增长率为0.127，透明溞为0.037，微型裸腹溞为0.471 d⁻¹，但在有沉积物的情况下种群增长率升高（分别为0.309、0.141和0.722 d⁻¹）。已结合这些数据在墨西哥浅水、浑浊水体中的重要性进行了讨论。
