EUGENOL COMO ANESTÉSICO PARA JUNDIÁS (Rhamdia quelen) ADAPTADOS A DIFERENTES NÍVEIS DE pH, TEMPERATURA E DUREZA DA ÁGUA

Abstract

The effects of water pH, hardness and temperature on anesthesia induction and recovery in silver catfish exposed to different concentrations of eugenol (20, 30 and 40 mg/L) were investigated. Moreover, the effects of anesthesia and temperature on blood gases tensions (PvO2 and PvCO2) and pH were also analyzed in juveniles I (3.5 ± 0.7 g; 7.7 ± 0.8 cm) and juveniles II (152.2 ± 3.4 g; 26.6 ± 3.3 cm) of silver catfish. Water quality and fish size affect efficacy of eugenol in silver catfish, mainly in the lower concentrations tested. Sedation of this species can be induced even with 20 mg/L, but for anesthesia a concentration of at least 40 mg/L eugenol must be used to reduce the influence of the studied fish size and water quality. Blood gases tensions and pH were affected by eugenol anesthesia only in fish acclimated to 30 oC.