LAUSR

Neotropical fish Cnesterodon decemmaculatus were exposed to different sublethal concentrations (0.5, 1.0 and 5.0 mg As/L) of sodium arsenite (As III) to determine the mean lethal concentration (LC50-96h) and to evaluate the response of a set of biomarkers (genotoxicity, behavioral, biochemical and metabolic). At the end of the exposure (96h), fish were video-recorded for behavior assessment. We used the micronucleus (MN) and nuclear abnormality (AN) tests and the comet assay (CA) in peripheral blood as genotoxicity biomarkers. In regard to biochemical and metabolic biomarkers, we dissected brain for acetylcholinesterase activity (AChE); liver for glutathione-S-transferase activity (GST), catalase activity (CAT) and glutathione content (GSH); gills for GSH content; and muscle for AChE, energy metabolism of lipids, carbohydrates and proteins, and electron transport system (ETS) activity of the mitochondrial chain. We calculated an index using metabolic biomarkers, the cellular energy allocation (CEA). The LC50 value was 7.32 mg As/L. As affected some swimming parameters in females. No significant differences in micronucleus were found with respect to the control, while nuclear aberrations increased significantly at 1.0 mg and 5.0 mg As/L. The genomic damage index and the percentage of cells with DNA damage (measured by comet assay) showed a significant increase in the As-treated groups, and this technique was the most sensitive to detect genotoxic damage. As affected the antioxidant system (mainly GSH, CAT and GST) and reduced lipid content. A preliminary baseline was generated for the response of C. decemmaculatus exposed to sublethal concentrations of As, provided that it alters swimming behavior and the antioxidant system, has genotoxic effects and reduces lipid content. This article is protected by copyright. All rights reserved.© 2022 SETAC.