Benzocaine and eugenol as anesthetic for Pimelodus britskii (‘mandi-pintado’) juveniles

Abstract

During the management practices in fish farming, the use of anesthetic drugs can configure a security to the producer, as these products have the ability to reduce the metabolism of animals. The present study aimed to find the best dose of benzocaine and eugenol for anesthesia induction and recovery in ‘mandi-pintado’ juvenile. One hundred and four fish with an average weight of 55.6 ± 15.3 g and mean total length 18.4 ± 1.4 cm were used. The study was conducted in a completely randomized design with 13 treatments, i.e. seven different concentrations of eugenol (40, 70, 100, 130, 160, 190 and 220 mg L-1) and six concentrations of benzocaine (125, 150, 175, 200, 225 and 250 mg L-1), where for each treatment eight randomly chosen fish (n = 8) were used and exposed individually for each concentration. Eugenol for anesthesia was effective in ‘mandi-pintado’ in different doses. However, benzocaine concentration of 125 mg L-1 was not efficient. Under the experimental conditions, the best concentration of eugenol for anesthesia induction and recovery in ‘mandi-pintado’ was 70 mg L-1 and of benzocaine was 200 mg L-1.