Effects of Microplastic Concentrations on the Survivability and Reproduction of Moina Macrocopa

In recent years, a large number of microplastics (MPs) appeared in the aquatic environment, causing serious pollution.In order to study the influence of MP concentrations on freshwater zooplankton, polystyrene microspheres (PS) of 0.5 μm were used in this study as experimental reagents, and Moina macrocopa, which was dominant zooplankton in the Pearl River Basin of China, was selected as the experimental object.The experiment was divided into four treatment groups plus a control group, and it was conducted for 15 days.The treatment groups had MP concentrations of 10, 10 2 , 10 3 and 10 4 pieces/mL.The survival time, reproduction rate, the total offspring, and the time of first pregnancy of Moina macrocopa were counted every day, and the intrinsic growth rate, generation time, and net reproduction rate were calculated.The results showed that the survival time of Moina macrocopa decreased with the increase of the MP concentration, and the MP concentration had more influence on the reproduction rate.Except for the 10 pieces/mL treatment group, no reproduction occurred in other treatment groups, and the reproduction rate gradually decreased with the increase of age.The life table showed that only the control group and the 10 pieces/mL treatment group had an intrinsic growth rate, and the intrinsic growth rate of the treatment group was far lower than that of the control group.Our experimental results provide basic data and a theoretical basis for further understanding the toxic effects of MPs on freshwater zooplankton.