Benzocaine and clove oil as anesthetics for pejerrey (Odontesthes bonariensis) fingerlings

J. Morato-Fernandes,S.R.N. Piedras,J.L.O.F. Pouey,R.A. Tavares,C. B. Rocha

doi:10.1590/s0102-09352013000500024

J. Morato-Fernandes, S.R.N. Piedras + Show 3 more

Open Access

https://doi.org/10.1590/s0102-09352013000500024

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Abstract

Pejerrey (Odontesthes bonariensis) is a native species from Rio Grande do Sul, Uruguay and Argentina where it is of great economic importance for artisanal fishing. One difficulty in laboratory research with pejerrey is related to its sensitivity, as it presents higher basal cortisol levels than other freshwater species. For this reason, the aim of this work was to evaluate the efficiency of benzocaine and clove oil as anesthetics for pejerrey fingerlings. Two experiments were done where fingerlings (57±7.8mm and 1.1±0.44g) were exposed to benzocaine with concentrations between 40mgL-1 and 120mgL-1 and to clove oil with concentrations between 12mgL-1 and 75mgL-1. Survival, anesthesia induction time and recovery time for each pharmaceutics were evaluated. Both benzocaine and clove oil pharmaceutics showed efficiency as anesthetics for pejerrey fingerlings, with negative correlation between the dose of anesthetics and the anesthesia induction time. For benzocaine, the concentrations between 80mgL-1 and 100mgL-1 showed better results, as for clove oil the optimal concentrations were between 25mgL-1 and 50mgL-1. On the other hand, the anesthesia recovery time did not present significant variation on the different concentrations of the tested products. The tested products are highly metabolizable by pejerrey.

Highlights

The use of native species in aquaculture has a number of advantages, mainly because they do not present environmental constraints, are adaptable to local climate and there is already a consumer market
Pejerrey has been the subject of studies related to reproduction and bio-ecology, there are few studies related to its handling techniques, due its sensitivity caused by higher basal cortisol levels than other freshwater species (Tsuzuki et al, 2001), which hinders laboratory research
The Federal Law No.11,794, 2008 that provides for the maintenance of an institutional national database of the Ethics Committees of Animal Use (CEUAs) (Brazil, 2008), has led to greater severity in conducting scientific research using animals, outlining handling standards, which in turn are not known for many species. In this sense this study aims to evaluate two anesthetics, which allow the appropriate handling of Odontesthes bonariensis fingerlings

Summary

Introduction

The use of native species in aquaculture has a number of advantages, mainly because they do not present environmental constraints, are adaptable to local climate and there is already a consumer market. Pejerrey has been the subject of studies related to reproduction and bio-ecology, there are few studies related to its handling techniques, due its sensitivity caused by higher basal cortisol levels than other freshwater species (Tsuzuki et al, 2001), which hinders laboratory research. Moreira and Volpato (2004) claim that stress is a factor more responsible for the occurrence of disease and mortality in aquaculture, and in fish the recovery from a mnemonic stressful experience induces increased plasma levels of cortisol. The Federal Law No.11,794, 2008 that provides for the maintenance of an institutional national database of the Ethics Committees of Animal Use (CEUAs) (Brazil, 2008), has led to greater severity in conducting scientific research using animals, outlining handling standards, which in turn are not known for many species

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