Eugenol and benzocaine as anesthetics for juvenile common carp (<i>Cyprinus carpio</i>)

Abstract

Anesthetics such as benzocaine and eugenol are efficiently used in fish to reduce stress both in the management of animals as for transport and reproduction. The aim of this study was to evaluate the induction times and recovery of juvenile common carp (Cyprinius carpio) exposed to both anesthetics, benzocaine (12,5; 25; 37,5; 50; 62,5; 75; 87,5; 100 e 112,5 mg L^-1) and eugenol (12,5; 25; 37,5; 50; 62,5; 75 e 87,5 mg L^-1). Hundred and thirty six juveniles were used with a mean weight of 1.92 ± 0.59 g and mean total length of 5.25 ± 0.52 cm. The benzocaine proved more efficient than eugenol over time, thus to induce coma as to recover the scape and also with regard to survival. The doses of benzocaine with best results were 87.5 and 100 mg L^-1. Eugenol delay resulted in the induction and recovery of the animals, and also presented anesthetic mortality when doses were increased.