Toxicity of endosulfan on embryo-larval development of the South American toad, Rhinella arenarum.

GABRIELA SVARTZ; CRISTINA PÉREZ-COLL; IANINA WOLKOWICZ HUTLER

ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY

SETAC PRESS

Lugar: Buenos Aires; Año: 2014 vol. 33 p. 875 - 881

0730-7268

Endosulfan (ES) is a widely used pesticide despite its extreme toxicity on a variety of taxa and its worldwide banish. In this context, the aim of this study was to evaluate the acute and chronic toxic effects of ES on the embryo-larval development of the common South American toad, Rhinella arenarum. The results showed that lethal and sublethal effects increased with concentrations and exposure time. The sensitivity to ES significantly incremented toward the larval period, being the complete operculum (S.25) the most susceptible stage (504-h LC50=0.01 mg ES/L; LC10=0.004 mg ES/L). With respect to sublethal effects, ES caused morphological abnormalities such as delayed development, edema, gill malformations, cellular dissociation, reduced body size, as well as marked behavioral alterations. Our results also showed that larvae exposed to concentrations of 0.005 and 0.01 mg ES/L completed the metamorphosis earlier than controls, but with reduced size and weight. The 240-h Teratogenic Index (TI) was 6.03. Considering that the Hazard Quotients (HQ) for chronic exposure were over the level of concern value (LOC), and toxicity parameters obtained in this study for Rhinella arenarum are lower than the levels of ES reported in the environment, this pesticide should be considered a potential risk for this species.