Respiratory metabolism of “Carassius auratus” in different concentrations of eugenol

Abstract

The study aimed to evaluate the use of eugenol as an anesthetic for Carassius auratus measuring time to anesthesia induction in different concentrations and their effects on gas exchange breathing. The fish were exposed to concentrations of 20, 40, 80, 120, 150 mg L-1 of eugenol. The results were analyzed according to a completely randomized design with six treatments and five replications were submitted to analysis of variance and when significant, averages were compared by Student's test (α = 0,05). the probability 5%. PaO₂e PaCO₂ values were submitted to polynomial regression (p > 0.05). The sedation and recovery time it’s the evaluation. Blood was withdrawn for hematological parameters analysis, pH, partial pressure of oxygen (PaO₂), partial pressure of carbon dioxide (PaCO₂), bicarbonate (HCO-₃) and glucose. Concentrations above 80 mg.L-1 presented sedation with 62 sec. The recovery has inverse correlation to time of anesthesia. Anesthetic induction of: C. auratus to different concentrations of eugenol provided 27.5 elevation on the values of percentage of hematocrit and erythrocyte number 37 and an increase in plasma glucose. C. auratus when subjected to the increased concentration of eugenol showed decrease in blood oxygen pressure (PaO₂), and increase in pressure of carbon dioxide (PaCO₂). The use of eugenol makes handling the fish farms, the recommended dose is 40 mg. L^-1 for Carassiusauratus that minimize the risks inherent in routine anesthetic procedures, with less cardiovascular impairment and, therefore, reducing the risk of death.