ESSENTIAL OIL OF Aloysia triphylla IS EFFECTIVE IN NILE TILAPIA TRANSPORT

The study evaluated the use of the essential oil of Aloysia triphylla (EOAT) as stress reducer in transporting Nile tilapia, Oreochromis niloticus. Juveniles were transported for 8 h in plastic bags by car with water containing 0 (control), 20 or 30 mu L L-1 EOAT (three replicates). We evaluated water quality, net ion fluxes (Cl-, Na+ and K+) and, plasma parameters (cortisol, glucose, lactate and paraoxonase) and ventilatory rate (VR) of Nile tilapia. There was no mortality in juveniles undergoing transport. Nile tilapia transported with 20 or 30 mu L L-1 EOAT presented lower pH than control group and with 30 mu L L-1 EOAT presented lower water conductivity, alkalinity and Cl-, Na+ and K+ net ion fluxes compared to other treatments. The EOAT did not alter plasma cortisol and paraoxonase levels, but reduced VR, and 30 mu L L-1 EOAT reduced plasma glucose levels compared to the control group after transport. The use of 20 mu L L-1 EOAT increased plasma lactate levels compared to other treatments. The use of 30 mu L L-1 EOAT for sedation in 8 h transport of Nile tilapia is recommended because it improved water quality and reduced ionic losses, plasma glucose levels and VR.