Toxicidade e genotoxicidade de imidacloprid em girinos de Leptodactylus latrans e Physalaemus cuvieri (anura: leptodactylidae)

Abstract

Imidacloprid is a neonicotinoid insecticide widely used worldwide, but which can cause adverse effects on non-target organisms, especially in aquatic environments. This study aimed to evaluate the chronic toxicity of an insecticide-based imidacloprid in amphibians, using Leptodactylus latrans and Physalaemus cuvieri tadpoles. The parameters of survival, swimming activity, body size, damage to body structures and genotoxicity for both species were analyzed; and the ecological risk of this insecticide calculated. Chronic short-term assay was carried out for 168 h (7 days) and five concentrations of imidacloprid, between 3 and 300 μg L-1, were tested. The insecticide did not affect the tadpoles survival tadpoles; however, both species tested showed smaller body size, damage to the mouth and intestine and the induction of micronuclei and other erythrocytes nuclear abnormalities after exposure to imidacloprid-based herbicide. Insecticide exposure affected the swimming activity in L. latrans, which contributes to the greater sensitivity of L. latrans to imidacloprid when compared to P. cuvieri. All parameters analyzed indicated that the insecticide presents an ecological risk for both species at concentrations greater than 3 μg L-1. This demonstrates the genotoxicity of the insecticide imadacloprid, which can contribute to the population decline of L. latrans and P. cuvieri species in natural systems.