Mentol como anestésico para diferentes classes de tamanho de tilápia do nilo

Abstract

The aim of this study was to evaluate the menthol as an anesthetic for various size classes of Nile tilapia. We evaluated three size classes: fingerlings, juveniles and adults, subjected to six concentrations of menthol (30, 60, 120, 180, 240 and 300 mg L-1), individually exposed for 10 minutes to the anesthetic solution and monitored during the induction and recovery. To fingerlings, juveniles and adults the recommended concentrations to reach the stage of deep anesthesia were 60 (124,8 ± 6,9 s), 180 (202,7 ± 17,0 s) and 240 (210,5 ± 17,3 s) mg L-1, respectively. The recovery times for the concentrations above were in the same order, from 306,2 ± 27,1, 202,7 ± 17,0, and 328,6 ± 32,0 s. For the induction stage of surgical anesthesia, the concentrations were 60 (172,8 ± 10,1 s), 120 (313,7 ± 14,7 s) for fingerlings and juveniles, respectively. The use of menthol as an anesthetic is effective, varying between the different size classes of Nile tilapia.