Eco-toxicology effect on Moina mongolica Daday exposed to Cd2+, Pb2+, and Hg2+ by the food chain.

As one of the most important contaminants, heavy metals can seriously influence human health via the food chain. In this study, the eco-toxicological effects of Cd2+, Pb2+, and Hg2+ on Moina mongolica Daday were investigated by feeding them Chlorella sp. that contained heavy metals. The relative body lengths of the M. mongolica changed rapidly, peaking at 2 days for Hg2+, 6 days for Cd2+, and 8 days for Pb2+. Moreover, grazing and clearance rates of the experimental group were apparently lower than those of the control group after immersion in heavy metals. Additionally, Cd2+ and Pd2+ in the food significantly influenced the mean lifespan of M. mongolica of the P and F1 generations. Egg production per brood was also significantly impacted by Cd2+ and Pb2+ in the food in generation P. Interestingly, Pb2+ was the only metal that significantly influenced the reproduction times of F2, while the reproductive times were significantly influenced by Cd2+ for generation P. Moreover, Cd2+, Pb2+, and Hg2+ in the food significantly influenced the fecundity of generation P. Evaluation of the population growth parameters of M. mongolica revealed that the intrinsic rate of increase, net reproduction rate, and finite rate of increase were significantly influenced by Cd2+, Pb2+, and Hg2+ in the food in generation P. Additionally, Hg2+ slightly impacted generation time for generation P. Finally, the acute toxicity toward M. mongolica was Hg2+ > Cd2+ > Pb2+. Overall, heavy metals in the food were likely to influence the growth, survival, and population growth of M. mongolica through the food chain.