Evaluation of the genotoxic and cytotoxic effects of glyphosate-based herbicides in the ten spotted live-bearer fish Cnesterodon decemmaculatus (Jenyns, 1842)

Mortality, genotoxicity, and cytotoxicity of the 48% glyphosate-based formulations Panzer and Credit® were evaluated on Cnesterodon decemmaculatus (Jenyns, 1842) (Pisces, Poeciliidae) under laboratory conditions. Induction of micronuclei (MN) and alterations in the erythrocytes:erythroblasts ratio were employed as end points for genotoxicity and cytotoxicity, respectively. For Panzer®, mean values of 16.70 and 15.68 mg/L were determined for LC50 at 24 and 96 h, respectively, and these concentrations reached mean values of 98.50 and 91.73 mg/L for Credit®. LC50 values decreased as a negative linear function of Panzer® exposure time within the 0–96 h period, but not for Credit®. LC50 values indicated that the fish were more sensitive to Panzer® than to Credit®. Both 3.9 and 7.8 mg/L of Panzer® increased MN frequency at 48 and 96 h of treatment. When fish were exposed to Credit®, an increased frequency of MN over control values was found after 96 h for all concentrations assayed, but not after 48 h. No cellular cytotoxicity was found after Panzer® and Credit® treatment, regardless of both the concentration and the sampling time. Furthermore, our results demonstrated that Panzer® and Credit® should be considered as glyphosate-based commercial formulations with genotoxic but not cytotoxic effect properties.

► Glyphosate-based formulations Panzer® and Credit® were evaluated on Cnesterodon decemmaculatus.
► Formulations were evaluated by mortality, genotoxicity, and cytotoxicity of endpoints.
► Both Panzer® and Credit® increased MN frequency at 48 and 96 h of treatment.
► No cellular cytotoxicity was found after Panzer® and Credit® treatment.
► Formulations should be considered with genotoxic but not cytotoxic effects.