Evaluation of silver nanowires (AgNWs) toxicity on reproductive success of Daphnia magna over two generations and their teratogenic effect on embryonic development

摘要

This study assessed the reproductive toxicity of silver nanowires (AgNWs) in Daphnia magna over two consecutive generations. An acute immobilization test was conducted according to the OECD 202 guidelines. To perform reproductive toxicity tests in both F0 and F1 generations, the animals were exposed to different concentrations of AgNWs (0, 0.4, 2, 10, and 50 ?g L-1) and pyriproxyfen (0.4 ?g L-1), as a positive control, based on the OECD 211 principles. Overall, AgNWs were acutely toxic to D. magna with EC50 value of 0.063 mg L-1. Compared to the control groups, AgNWs disrupted reproductive performances of D. magna through increasing the egg development time and time to production of first brood as well as decreasing the total offspring production and molting frequency in both F0 and F1 generations. After exposure to AgNWs, the number of male neonates and non-reproductive females increased in the F0 generation, whereas just male neonates raised in the F1 generation. Moreover, AgNWs caused several congenital anomalies including underdeveloped antennae, 2nd antennae, malpighian tube, rostrum, sensory bristles, tail spine, and malformed eyes. Together, AgNWs could disrupt reproductive health of D. magna, and these types of bioperturbations could dramatically change the good health state of aquatic ecosystems.