Toxicidade do herbicida atrazina em "Colossoma macropomum"

The present study aimed to investigate the toxicity of the herbicide GESAPREME, belonged to the Triazines group (the active principle is atrazine = 500gL-1), on the juveniles of the fish species Colossoma macropomum (tambaqui). For this purpose, the LC50 and the frequency of micronuclei (MN) in erythrocytes were determined. Fish mortality increased together with the increment in water GESAPREME concentrations. The value of LC50 (96h) was reached in the concentration of 20 mg L-1. After 48h of herbicide exposition, hemorrhages could be noted in the whole body of fish exposed to the concentrations of 20, 22 and 25 mg L-1. The number of micronuclei in erythrocytes increased significantly during the exposition of fish to GESAPREME concentrations of 10, 20 and 30 mg L-1, when compared to the control group. The herbicide action was clearly capable to induce micronuclei formation in the erythrocytes of Colossoma macropomum. These results suggest that cells are seriously damaged in its integrity by the exposition to GESAPREME, due to the high micronuclei incidence observed in erythrocytes. Agribusiness has been expanded in Brazil and the risk of water rivers and aquaculture contamination by xenobiotics agents has been increased. Therefore, the detection of pesticide and their effects on the organisms have been became important studies, since they can predict the impact of these products on live organisms.