Study on the Microplastics’ Effect on the Life History of Daphnia magna

International Genome Center, Jiangsu University, Zhenjiang 212013, China

^* Corresponding author: zhaoby@ujs.edu.cn

Abstract

Microplastics (MPs), a type of new pollutant, have shown negative impacts on the aquatic environment. To understand how MPs impact zooplanktons, we studied the life history of Daphnia magna. D. magna those fed with fluorescent microspheres at two different concentrations (0.1mg/L and 1mg/L) and particle sizes respectively (0.1μm and 5μm). The results showed that MPs negatively affected the growth and reproduction of D. magna significantly. Specifically, the impact of higher concentration of 5μm microspheres > high concentration of 0.1μm microspheres > low concentration of 0.1μm microspheres > low concentration of 5μm microspheres. In addition, prolonged feeding time in large-particle-size microspheres (5μm) enhanced the ingestion of microspheres by D. magna, resulting in higher impact on life history. In conclusion, smallparticle-size microspheres (0.1μm) are more harmful at low concentrations. However, microplastic pollution shows impacts only on the life history (growth and reproduction), but not the survival rate of D. magna in our study.