Anesthetic induction and recovery time of Centropomus parallelus exposed to the essential oil of Aloysia triphylla

Indução e recuperação anestésica de Centropomus parallelus expostos ao óleo essencial de Aloysia triphylla

ABSTRACT:

This study analyzed the effectiveness of the essential oil of Aloysia triphylla (EOA) as an anesthetic and stress reducing agent in the transport of fat snook (Centropomus parallelus ). Juveniles were exposed to different concentrations of EOA (seawater-adapted: 25-300μL L^-1; freshwater-adapted: 200μL L^-1) to identify the anesthetic induction and recovery times. In an additional experiment, seawater-adapted fat snook were transported in plastic bags with 10 or 20μL L^-1 EOA for 6 or 24h. The increased concentration of EOA proportionally decreased the time required for anesthesia induction. Mortality was 30 and 70% in fat snook transported with 10 and 20µL L^-1, respectively, 24h after transport. The addition of 20µL L^-1 EOA significantly reduced plasma cortisol levels during transport compared to the control group, but increased blood glucose levels after 6 and 12h of transport. The EOA reduced total ammonia and dissolved oxygen levels at the end of transport compared to control fish. The EOA is recommended for sedation (25-50µL L^-1) and anesthesia (100-300µL L^-1) but not for transport of fat snook because it increased mortality.

Key words:
anesthesia; blood parameters; fat snook; natural product; transport