Óleos essenciais de Cymbopogon citratus e Lippia sidoides na indução anestésica e no transporte de acará bandeira(Pterophillum scalare).e)

Abstract

The aim of this study was to verify the effects of essential oils from Lippia sidoides (EOLS) and Cymbopogon citratus (EOCC) on the anesthetic induction and recovery of freshwater angelfish, as well as their viability as a sedative during transport. Freshwater angelfish juveniles I (0.82 g) and II (2.40 g) were exposed to different concentrations of EOLS and EOCC: 0, 10, 25, 50, 75, 100, 150, 200 and 250 mg L-1. Ventilatory frequency (VF) and transport for 8 h with 0, 10 and 15 mg L-1 of each essential oil were also evaluated in juveniles II. The minimum concentration of both essential oils capable of causing sedation was 10 and 25 mg L-1 for juveniles I and II, respectively. The best times of anesthesia for both essential oils were obtained with 200 and 250 mg L-1 for juveniles I and II, respectively. Blood glucose levels were higher in animals transported with 10 and 15 mg EOLS L-1 and 15 mg EOCC L-1. Hepatic glycogen levels were higher in animals transported without the addition of the essential oils. Juveniles II sedated with EOLS had lower VF than the other treatments. For transported fish, the volume of gill tissue and filament epithelium was smaller in fish of the control and 15 mg EOLS L-1 groups. For secondary lamella, the lowest values occurred in fish from the 10 mg EOLS L-1 treatment. In general, fish transported with 10 mg EOLS L-1 showed less gill alterations than other transported fish. When the type of lesion was evaluated, the greatest changes occurred for the treatments 10 and 15 mg EOCC L-1. In conclusion, EOLS and EOCC are efficient for handling at concentrations of 200 and 250 mg L-1 for juveniles I and II, respectively. For transport of juveniles II for up to 8 h, 10 mg L-1 of OELS can be used, because although this concentration has increased blood glucose, it decreased VF, did not affect water quality and did not cause irreversible damage to the gill tissue.