Comparative population growth of Ceriodaphnia dubia and Daphnia pulex (Cladocera) exposed to zinc toxicity
Por:
Sanchez-Ortiz, JR, Sarma, SSS, Nandini, S
Publicada:
1 ene 2010
Categoría:
Environmental Engineering
Resumen:
Population growth of two cladocerans (Ceriodaphnia dubia and Daphnia pulex) exposed to 4 different concentrations of ZnCl(2) (0.125, 0.25, 0.5 and 1.0 mg L(-1), plus controls) at one algal food (Scenedesmus acutus) density (0.5X10(6) cells mL(-1)) was quantified for 30 days. Population densities of C. dubia and D. pulex decreased with increasing concentration of Zn in the medium. At a concentration of 1 mg L(-1) of ZnCl(2), both C. dubia and D. pulex did not reproduce and died within a week. The peak population densities of C. dubia ranged from 0.2 to 6.0 ind. mL(-1), depending on the Zn level in the medium, whereas this range was lower for D. pulex (0.2 to 4.1 ind. mL(-1)). The peak population density was inversely related to the Zn concentration. The rate of population increase (r) varied from -0.12 to +0.14 and -0.02 to +0.23 per day for C. dubia and D. pulex, respectively, depending on the Zn level in the medium. Statistically, both the peak population density and the r were signif
Filiaciones:
Sarma, SSS:
Univ Nacl Autonoma Mexico, Div Res & Postgrad Studies, Lab Aquat Zool, Tlalnepantla 54000, State Of Mexico, Mexico
Nandini, S:
Univ Nacl Autonoma Mexico, UIICSE, Tlalnepantla 54000, State Of Mexico, Mexico
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