Assessment of the effect of a commercial formulation of Methomyl on reproduction of Daphnia obtusa Kürz (1874)

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Abstract

The aim of this study was to evaluate the effect of a commercial formulation of Methomyl on the reproduction in Daphnia obtusa. Neonates (<24 h) were exposed to concentrations of insecticide (1.0, 1.5, 2.0, 2.5, 3.0 µg L^-1) for a period of 21 days. The results showed a significant decrease in the number of molts, total neonates, fertility and sex ratio index. Significant regressions were found between reproductive parameters and concentrations of the insecticide: molts (R²= 0.96), fertility (R²= 0.97), number of female neonates born per female (R²= 0.90), and the number of male neonates born per female (R²= 0.94). Embryotoxicity was also observed; the number of neonates born with malformations increased in the highest concentrations of Methomyl 90 SP® tested. In conclusion, Methomyl 90 SP® inhibits reproduction of D. obtusa. However, a clear effect as an endocrine disrupter was not observed. This insecticide is embryotoxic; it causes malformations in neonates of Daphnia obtusa.

Gaete, H., Olivares, Y., & Escobar, C. (2017). Assessment of the effect of a commercial formulation of Methomyl on reproduction of Daphnia obtusa Kürz (1874). Latin American Journal of Aquatic Research, 41(5), 979-984. doi:http://dx.doi.org/10.3856/vol41-issue5-fulltext-16

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