Nandini S, Picazo-Paez E A, Sarma S S S
Laboratory of Aquatic Zoology, Division of Research and Postgraduate Studies, National Autonomous University of México, Campus Iztacala, Mexico.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2007 Aug;42(10):1433-42. doi: 10.1080/10934520701480789.
In this work we evaluated the effect of temperature (22 degrees and 27 degrees C), algal density (Chlorella vulgaris 0.5 x 10(6) and 2.0 x 10(6) cells/mL) and different combinations of 2 heavy metals (Zn at 25.25-101.0 microg/L and Cu at 17.75-71.0 microg/L) on the population level variables of Moina macrocopa. Median lethal concentration (24 h bioassay at 1 x 10(6) cells/mL of algal diet) of Zn and Cu for M. macrocopa were 1010 microg/L and 710 microg/L, respectively. In the survivorship curves at 27 degrees C there was a reduction in the survival of cladocerans exposed to Cu compared to controls or Zn. The fecundity curves (m(x)) indicated a steady reproductive output throughout the life span of M. macrocopa, but the negative impact of copper was more than that of zinc. Reproductive phase of M. macrocopa was longer at 22 degrees C than at 27 degrees C. The average lifespan was higher at 22 degrees C and at the higher food level. It was significantly affected by temperature, food level and toxicant concentration, as well as their interaction. The net reproductive rate was also influenced by food and temperature but not by the toxicant level. The generation time ranged between 4-8 days and was lower at 27 degrees C. The population growth rate (r) derived from life table experiments varied from 0.6 to 0.9 per day, depending on the treatment. Regardless of the toxicant level, at 22 degrees C, the population growth was higher at the higher food level. In treatments containing only Cu, the population growth of M. macrocopa was lower than when present together with Zn. Peak population densities of around 30 ind./mL were reached under high food conditions. Higher temperature and lower food level had an adverse effect on M. macrocopa in treatments containing only Cu. In the presence of higher food density, the adverse impact of copper was not evident. The r derived from growth study ranged from 0.25 to 0.64 per day depending on the test conditions. Data were interpreted in terms of sensitivity M. macrocopa for its possible use as a complement, but not as an alternative to Daphnia magna for evaluating the toxicity of heavy metals.
在本研究中，我们评估了温度（22摄氏度和27摄氏度）、藻类密度（普通小球藻0.5×10⁶和2.0×10⁶个细胞/毫升）以及两种重金属的不同组合（锌浓度为25.25 - 101.0微克/升，铜浓度为17.75 - 71.0微克/升）对大型溞种群水平变量的影响。大型溞对锌和铜的半数致死浓度（以1×10⁶个细胞/毫升藻类为食物进行24小时生物测定）分别为1010微克/升和710微克/升。在27摄氏度下的存活曲线中，与对照组或锌处理组相比，暴露于铜的枝角类动物存活率降低。繁殖力曲线（m(x)）表明大型溞在整个生命周期内繁殖产出稳定，但铜的负面影响大于锌。大型溞在22摄氏度下的繁殖期比在27摄氏度下更长。在22摄氏度和较高食物水平下，平均寿命更长。它受到温度、食物水平、毒物浓度及其相互作用的显著影响。净增殖率也受食物和温度影响，但不受毒物水平影响。世代时间在4 - 8天之间，在27摄氏度下较短。根据处理方式不同，生命表实验得出的种群增长率（r）每天在0.6到0.9之间变化。无论毒物水平如何，在22摄氏度下，较高食物水平时种群增长更高。在仅含铜的处理中，大型溞的种群增长低于与锌共存时。在高食物条件下，种群密度峰值约为30个/毫升。在仅含铜的处理中，较高温度和较低食物水平对大型溞有不利影响。在食物密度较高时，铜的不利影响不明显。根据测试条件不同，生长研究得出的r每天在0.25到0.64之间变化。数据从大型溞的敏感性角度进行了解释，其可能用作补充，但不能替代大型蚤用于评估重金属毒性。
