Óleo de cravo como anestésico em adultos de tilápia-do-nilo

Abstract

The objective of this study was to test the efficiency of clove oil as an anesthetic for adult tilapia (Oreochromis niloticus) and to evaluate, sensorially, the aroma and taste of fillets after anesthesia. In the first experiment, fish were exposed to different clove oil concentrations (0, 100, 150, 200, 250 and 350 mg L-1) of anesthetic baths. In the second experiment, different times of exposure (10, 20 and 30 minutes) to anesthesia were evaluated. Finally, the aroma and taste of the tilapia fillets, when exposed to optimal concentration of clove oil, were tested. The concentration of 250 mg L-1 of clove oil was adequate to induce lower opercular movement in adult tilapia, and for anesthesia for biometrics and brief management, the recommended concentration is 100 mg L-1. Fillets from tilapia anesthetized with clove oil showed a moderate difference in aroma and taste just after anesthesia. Thus, clove oil is an effective anesthetic for the management of adult tilapia as a routine procedure in fish farming, however tilapias should be slaughtered 12 hours after exposure to the drug, so as not to change the organoleptic characteristics of anesthetized fishes.