BIOMARCADORES COMPORTAMENTAIS E MUTAGÊNICOS EM GIRINOS DE RÃ TOURO (LITHOBATES CATESBEIANUS) EXPOSTOS À ABAMECTINA

Abstract

Abamectin (ABA) is marketed as a pesticide and can be found accidentally in aquatic environments and may cause various negative effects on organisms that are exposed to their chemical composition. In this study, we evaluated whether exposure to ABA at different concentrations [12.5%, 25% and 50% of the previously established median lethal concentration (LC50)] may lead to behavioral changes and mutagenic effect in L. catesbeianus tadpoles. Behavioral tests identified absence of aggregation, changes in swimming pattern and absence of defensive response of tadpoles exposed to pesticide. In addition, higher concentrations of the pesticide altered the morphology and pigmentation of the oral apparatus and caused nuclear alterations in the erythrocytes. Changes in anti-predatory behavior may have been caused by changes in the mechanisms of perception and defensive response due to the deleterious effect of ABA. Changes in oral morphology can have negative consequences on forage activity and feeding of individuals. In addition, increased nuclear abnormalities in erythrocytes confirm the mutagenic potential of ABA in tadpoles of L. catesbeianus. Our study confirms the hypothesis that the presence of ABA in aquatic environments can have negative impacts on tadpoles and therefore affect amphibian populations in natural ecosystems.