Effect of estradiol-17β on the sex ratio, growth and survival of juvenile common snook (Centropomus undecimalis)

• Published in: Acta scientiarum. Animal sciences 2014-07, Vol.36 (3), p.239-245
• Main Authors: de Carvalho, Cristina Vaz Avelar, Passini, Gabriel, Costa, Wanessa de Melo, Vieira, Beatriz Nunes, Cerqueira, Vinicius Ronzani
• Format: Article
• Language: eng ; spa
• Subjects: Aquaculture industry; Costs (Law); Estradiol; Fishes; Growth; hormone treatment; intersex; marine fish; Phenols; protandric; sex control; VETERINARY SCIENCES
• ISSN: 1806-2636; 1807-8672; 1807-8672
• DOI: 10.4025/actascianimsci.v36i3.22839

Sex control in fish is a promising technique for aquaculture, since it gives advantages associated with one sex. The aim of this study was to investigate the feminization of common snook (Centropomus undecimalis) by oral administration of two doses of estradiol-17β (50 and 100 mg [E.sub.2] [kg.sub.-1] feed) and control treatment for 45 days and to evaluate their effects on the sex ratio, growth and survival of common snook juveniles. After this period, fish were fed only with commercial feed without hormone supplementation. During the period of [E.sub.2] administration, the control fish grew more than those in the other treatments. At the end of the experiment in the treatment with 50 mg [E.sub.2] [kg.sub.-1], 26.32% of the fish were male, 68.42% were female, and 5.26% were intersex. In the treatment with 100 mg [E.sub.2] [kg.sub.-1], 10% of the fish were male, and 90% were female. There was no difference in growth among the treatments after 11 months. This study showed that it is possible to obtain 90% common snook females using feeds with 100 mg [E.sub.2] [kg.sub.-1] for 45 days without impairing the fish growth or survival. Keywords: sex control, hormone treatment, marine fish, intersex, protandric. O controle do sexo dos peixes e uma tecnica promissora na aquicultura, pois permite obter vantagens associadas a um dos sexos. Sendo assim, o objetivo deste trabalho foi avaliar o efeito do hormonio 17β-estradiol ([E.sub.2]) na feminizacao, crescimento e sobrevivencia de juvenis de robalo-flecha (Centropomus undecimalis). Durante 45 dias, os juvenis foram submetidos a tres dietas (controle, 50, 100 mg [E.sub.2] [kg.sub.-1] de racao) com tres repeticoes cada. Apos este periodo, os peixes passaram a ser alimentados somente com racao comercial sem adicao de hormonio. Durante o periodo de administracao do [E.sub.2], os peixes do controle cresceram mais que os dos outros tratamentos. No final do experimento, no tratamento com 50 mg [E.sub.2] [kg.sub.-1], 26% dos peixes eram machos, 68.42% eram femeas e 5.26% eram intersexo. No tratamento com 100 mg [E.sub.2] [kg.sub.-1], 10% dos peixes eram machos e 90% eram femeas. Apos 11 meses nao houve diferenca de crescimento entre os tratamentos. Este trabalho mostrou que e possivel obter 90% de femeas de robaloflecha utilizando racoes com 100 mg [E.sub.2] [kg.sub.-1] durante 45 dias sem danos ao crescimento ou a sobrevivencia. Palavras-chave: controle do sexo, tratamento hormonal, peixe marinho, intersexo, protandrico.