Clove Oil as Anesthetic for Tambacu Juveniles (♂Piaractus mesopotamicus × ♀ Colossoma macropomum)

Abstract

The objective of this study was to determine the clove oil (CLO) dose as an anesthetic for tambacu juveniles (♂Piaractus mesopotamicus × ♀ Colossoma macropomum) at two temperatures. Sixty-four animals (2.42 ± 0.39 g and 5.19 ± 7.5 cm) were used in a 4x2 factorial design, composed by four concentrations of CLO (25, 50, 75 and 100 mg L-1) and two temperatures (25 and 30 °C). Data were submitted to a two-way ANOVA followed by Tukey test. Linear regression analysis was also applied to correlate the induction and recovery times of fish. Deep anesthesia was achieved at all concentrations tested and no mortality was observed during the experimental procedure and after a 24-hour observation period. The shortest time for deep anesthesia (31.75 s) was observed at a concentration of 100 mg L-1 and a temperature of 30 °C, differing significantly from the other treatments. The longest recovery time (> 270 s) was observed at concentrations of 75 and 100 mg L-1 at both temperatures tested. A positive linear relationship between induction time and deep anesthesia (P<0.05) and a negative linear relationship between total recovery time (P<0.05) was observed. The CLO was effective to anesthetize tambacu juveniles in routine management activities. We recommend to use the 50 mg L-1 concentration of CLO and a temperature of 30 °C when considering the induction and recovery times for a deep anesthesia.