Toxicidad del atrazina en una especie de pez nativo Cnesterodon decemmaculatus: una evaluación inicial

Atrazine is a widely used pesticide with high persistence in the aquatic environment. This study aimed to assess the toxicity of an atrazine-based herbicide (Atramyl 90 WG®) in a native fish species, Cnesterodon decemmaculatus (Teleostei, Poeciliidae). Fish were exposed to a wide range of concentrations (0.5 - 100mg/L) for acute (96h) and subchronic (336h) periods. Lethality, ethological alterations, neurotoxicity and genotoxicity were evaluated. The 96 and 336 h-LC₅₀ were 74.03 and 13.61mg/L, respectively. Fish speed decreased at 10mg/L, but movement time was higher in the fish acutely exposed to 2mg/L. Inhibition of acetyl and butyrylcholinesterase activity was recorded at 96h in the highest concentration tested and increased butyrylcholinesterase activity in the lowest concentrations at both exposure times. Genotoxicity assessment showed increased notched and lobed nuclei frequency (1 - 10mg/L). Finally, risk assessment determined potential chronic risk, providing valuable evidence of atrazine toxicity.