Resumo -O objetivo deste trabalho foi avaliar o eugenol como anestésico para a tilápia-do-nilo. Para a concentração ideal, foram avaliados seis tratamentos (50, 75, 100, 150, 200 e 250 mg L -1 ), com dez peixes por tratamento, anestesiados individualmente, acompanhados durante a indução e recuperação. A toxicidade foi estimada pela submissão de 210 peixes a 7 concentrações de eugenol (50, 75, 100, 150, 200, 250,
Eugenol as an anesthetic for Nile tilapiaAbstract -The objective of this work was to evaluate eugenol as anesthetic for Nile tilápia. For the best concentration of the anaesthetic, six treatments (50, 75, 100, 150, 200, and 250 mg L -1 ) were evaluated, with ten fi shes per treatment, anesthetised individually and monitored during the induction and recovery. Toxicity was estimated in 210 fi sh submitted to seven eugenol concentrations (50, 75, 100, 150, 200, 250, and 300 mg L -1 ) for 600 s; and for safety margin, 120 fi sh were submitted to 75 mg L -1 for fi ve time intervals (600, 1,200, 1,800, and 2,400 s). The effective concentrations were 50 and 75 mg L were recommended. The higher therapeutic concentration costs R$ 0.065 per liter. Eugenol was effective for euthanasia at 286.55 mg L -1 for 600 s.
