Rafael Aldrighi Tavares

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

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.

Utilization of microsatellite markers to form families of "pejerrey" Odontesthes bonariensis in a genetic breeding program

Foram identificadas a divergencia e a variabilidade genetica, por meio do polimorfismo de seis marcadores microssatelites, de duas populacoes de Odontesthes bonariensis, utilizadas em manejos de cultivo e com potencial para fornecimento de reprodutores para programas de melhoramento genetico. Do total de seis loci, cinco demonstraram eficiencia para analise genetica nas duas populacoes de O. bonariensis. A diferenciacao genetica significante nas populacoes analisadas pode fornecer a base para futuros programas de melhoramentos geneticos, atraves da combinacao de material das populacoes divergentes para o desenvolvimento de linhagens ou execucao de um programa de selecao.