Effect of menthol and eugenol on the physiological responses of pacu Piaractus mesopotamicus

Abstract

The present study the aim was evaluate induction time, recovery time and physiological responses of pacus Piaractus mesopotamicus submitted to eugenol and menthol usual doses. Were used 56 pacus, which were exposed to menthol 150 mgL-1 (n=24) and eugenol 100 mgL-1 (n=24) and the control group (n=24) which doesn’t were exposed to anesthetics. In the moment 0, 12 and 24 hours after induction were performed collection of blood in fish (n=8) for the hematologic parameters and plasma glucose evaluation. The recovery was conduced in aquariums free anesthetic, being induction and recovery times monitored. The results were submitted at analysis of variance (P<0.05) and the means when significant were compared by Tukey test (P<0.05). Both anesthetics in their respective concentrations induced fish to surgical anesthesia. There was no treatment effects on hematologic parameters, except for hemoglobin for which was observed interaction effect between factors, is significantly lower 150 mgL-1 showed significant reduction (P<0.05) of hemoglobin values 12 hours after induction, however these values remained unchanged 24 hours after anesthesia. Interaction effect (P<0.01) was observed between treatments and sampling times for the plasma glucose levels, because there was significant reduction in this levels 12 hours after anesthesia, and remained 24 hous after induction. Menthol 150 mgL-1 and eugenol 100 mgL-1 can be used safely in the pacus induction during realization of biometrics.