Cortisol Response in Nile tilapia, Oreochromis niloticus L., Following Acute Exposure to a Glyphosate-based Herbicide

Glyphosate-based herbicides are widely used in agricultural fields and are commonly applied in fish ponds to control algae and plant growth. Nile tilapia, Oreochromis niloticus L., fingerlings exposed to the highest sublethal concentrations of glyphosate alone experienced an increase in cortisol levels that was similar to the value found in the stressed group. In contrast, fingerlings exposed to all glyphosate concentrations in combination with an acute stressor had significantly lower cortisol levels than those found in the stressed group in clear water, suggesting that the herbicide attenuated the cortisol response to the additional acute stressor.