Genotoxic effects of the herbicide Roundup Transorb® and its active ingredient glyphosate on the fish Prochilodus lineatus

•The fish Prochilodus lineatus was exposed to glyphosate and Roundup Transorb® (RT).•Genotoxicity of glyphosate and RT was compared by using the comet assay.•Both glyphosate and RT were genotoxic to gill cells and erythrocytes of P. lineatus.

Roundup Transorb® (RT) is a glyphosate-based herbicide and despite its wide use around the world there are few studies comparing the effects of the active ingredient with the formulated product. In this context the purpose of this study was to compare the genotoxicity of the active ingredient glyphosate with the formulated product RT in order to clarify whether the active ingredient and the surfactant of the RT formula may exert toxic effects on the DNA molecule in juveniles of fish Prochilodus lineatus. Erythrocytes and gill cells of fish exposed to glyphosate and to RT showed DNA damage scores significantly higher than control animals. These results revealed that both glyphosate itself and RT were genotoxic to gill cells and erythrocytes of P. lineatus, suggesting that their use should be carefully monitored considering their potential impact on tropical aquatic biota.