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

Abstract

ABSTRACT. 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 2 kg -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 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 2 kg -1 , 26.32% of the fish were male, 68.42% were female, and 5.26% were intersex. In the treatment with 100 mg E 2 kg -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 2 kg -1 for 45 days without impairing the fish growth or survival.Keywords: sex control, hormone treatment, marine fish, intersex, protandric.Efeito do estradiol-17β na feminização, crescimento e sobrevivência de juvenis de robaloflecha (Centropomus undecimalis) RESUMO. O controle do sexo dos peixes é uma técnica promissora na aquicultura, pois permite obter vantagens associadas a um dos sexos. Sendo assim, o objetivo deste trabalho foi avaliar o efeito do hormônio 17β-estradiol (E2) na feminização, crescimento e sobrevivência de juvenis de robalo-flecha (Centropomus undecimalis). Durante 45 dias, os juvenis foram submetidos a três dietas (controle, 50, 100 mg E 2 kg -1 de ração) com três repetições cada. Após este período, os peixes passaram a ser alimentados somente com ração comercial sem adição de hormônio. Durante o período de administração do E 2 , os peixes do controle cresceram mais que os dos outros tratamentos. No final do experimento, no tratamento com 50 mg E 2 kg -1 , 26% dos peixes eram machos, 68.42% eram fêmeas e 5.26% eram intersexo. No tratamento com 100 mg E 2 kg -1 , 10% dos peixes eram machos e 90% eram fêmeas. Após 11 meses não houve diferença de crescimento entre os tratamentos. Este trabalho mostrou que é possível obter 90% de fêmeas de robaloflecha utilizando rações com 100 mg E 2 kg -1 durante 45 dias sem danos ao crescimento ou à sobrevivência.Palavras-chave: controle do sexo, tratamento hormonal, peixe marinho, intersexo, protândrico.

Effects of synthetic androgen (17α-methyltestosterone) and estrogen (17β-estradiol) on growth and skin coloration in emperor red cichlid, Aulonocara nyassae (Actinopterygii: Cichliformes: Cichlidae)

“…In the presently reported study, fish groups fed E 2 had no significant changes in growth parameters, which is in agreement with the results studied on Amatitlania nigrofasciata (see George and Pandian 1996) and Centropomus undecimalis (see Carvalho et al 2014). Similarly, studies on Xiphophorus helleri by Lim et al (1992) and Tamaru et al (2009) stated that the hormones did not have any adverse effect on the growth.…”

Induction of precocious females in the protandrous barramundi (Lates calcarifer) through implants containing 17β-estradiol - effects on gonadal morphology, gene expression and DNA methylation of key sex genes

“…For instance, feminization of testes was observed in juvenile Chum salmon (Oncorhynchus masou), for which sex is distinguishable by 25 day post-hatch (dph), by exposing individuals to 1 µL E 2 L -1 from 34-100 dph (Nakamura, 1984). Similarly, feminization of juvenile common snook (Centropomus undecimalis) was achieved in 90% of juveniles using feed supplemented with 100 mg kg -1 E 2 for 45 days (Carvalho et al, 2014) and in 100% of 3 year old male fish implanted with exogenous E 2 (Passini et al, 2016). Recently, feminization of juvenile barramundi was achieved using commercial pellets supplemented by 20 mg E 2 kg -1 feed from 30 -120 dph (Banh et al, 2020).…”

Preliminary Trial of Male to Female Sex Reversal by 17β-Estradiol in Combination with Trilostane in Spotted Scat (Scatophagus argus)

“…Zhou et al [29] found that E 2 had a negative effect on the growth of small yellow croaker (Larimichthys polyactis). Cravalho et al [30] showed that 50 and 100 mg•kg −1 E 2 had an inhibitory effect on the body length and body mass of common snook (Centropomus undecimalis). Blazquez et al [31] found that E 2 inhibited the growth of body mass in sea bass (Dicentrarchus labrax).…”