Embryonic development, hatchling performance and metabolic profile after egg exposure to environmentally relevant levels of chlorpyrifos in an aquatic turtle.

The extensive use of organophosphorus insecticides poses a threat to the survival of non-target organisms. Ecotoxicological outcomes of embryonic exposure to insecticides are rarely evaluated in various oviparous species. In this study, soft-shelled turtle (Pelodiscus sinensis) eggs were incubated in moist substrate containing different levels (0, 2, 20 and 200 µg/kg) of chlorpyrifos to investigate its toxic effects on embryonic development and survival, and hatchling physiological performance. Chlorpyrifos exposure had no significant impacts on embryonic development rate and egg survival in P. sinensis. Similarly, embryonic chlorpyrifos exposure neither obviously affected the size and locomotor performance of hatchlings, nor changed the activities of superoxide dismutase and catalase, and content of malondialdehyde in their erythrocytes. Based on liquid chromatography-mass spectrometry analysis, minor metabolic perturbations related to amino acid, lipid and energy metabolism in hatchlings after embryonic chlorpyrifos exposure were revealed by hepatic metabolite profiling. Overall, our results suggested that embryonic exposure to environmentally relevant levels of chlorpyrifos had only a limited impact on physiological performances of hatchlings, although it would result in a potential risk of hepatotoxicity in P. sinensis.