Deltamethrin-induced nuclear erythrocyte alteration and damage to the gills and liver of Colossoma macropomum

Deltamethrin is one of the most commonly used pyrethroids in the world, and it has a high toxic potential, mainly on aquatic organism. Thus, the purpose of this study was to evaluate LC 50 values of deltamethrin on tambaqui ( Colossoma macropomum ) fingerlings and to investigate genotoxic effects and histopathological responses. Fish were exposed to different concentrations of deltamethrin (0, 6.16 × 10 −3 ; 6.44 × 10 −2 ; 1.34 × 10 −1 , and 1.93 × 10 −1 mg L −1 ) for 96 h. In addition, a genotoxicity analysis was carried out on peripheral blood erythrocytes and histopathological changes were classified by the severity degree of damage and organ functioning. The 96 h LC 50 value for tambaqui was estimated at 5.56 × 10 −2 mg L −1 using a static test system. Nuclear abnormalities in exposed fish included micronuclei, blebbed, notched, 8-shaped, and binucleated nuclei forms. Deltamethrin significantly induced a notched nucleus compared to other abnormalities. A histopathological examination showed hepatic lesions and gill damage. Deltamethrin was found to be highly toxic; it induced genotoxicity and caused liver and gill inflammation in tambaqui.