Effects of different doses of eugenol on plasma cortisol levels and the quality of fresh and frozen-thawed sperm in South American catfish (Rhamdia quelen).

The production of captive fish is only possible through artificial reproduction, but manipulation is a known stressor stimulus. Thus, the objective of the present study was to evaluate the effects of different eugenol concentrations (0, 30, 40, 50 and 60 mg/L) during reproductive management of Rhamdia quelen. Seventy-five mature male R.