Artificial sex reversal of white grouper ( Epinephelus aeneus ) utilizing aromatase inhibitor (Fadrozole)

Abstract

The white grouper is a desirable aquaculture species that adapts to captivity, grows well and commands a high market price. However, little is known about reproductive biology or control of sex reversal of this protogynous hermaphrodite. In this study, female white groupers were implanted with one dose of 17α‐methyltestosterone (10 mg/kg body weight [BW], MT) and two doses of aromatase inhibitor, fadrozole (1 and 3 mg/kg BW, FD1 and FD3) once a month for 4 months (April–July). At the start of the study, the fish had gonads full of oocytes compared to the end of the experiment when the control group mature oocytes compared to the experimental groups MT, FD1 and FD3 that exhibited different stages of testicular tissue. Plasma levels of testosterone were significantly highest in the FD3 group and the highest 11‐Ketotestosterone levels were observed in the MT group. Plasma levels of oestradiol (E2) were significantly lower in the FD implanted groups, compared to initial individuals and control groups. The use of aromatase inhibitor, FD for sex reversal both gives further insight into the mechanisms controlling sex differentiation and provides an alternative to steroid treatment.

Reproductive biology of paradise threadfin Polynemus paradiseus (Linnaeus, 1758) from Shibsa River in Bangladesh

“…Paired ovaries with mature oocytes were observed at the mature stage of paradise threadfin. The six stages of oocyte developments was found in E. aeneus [35]. In the present study, month-wise ovarian maturation stages were observed histologically for female P. paradiseus.…”

Sex Reversal Induced by Dietary Supplementation with 17α-Methyltestosterone during the Critical Period of Sex Differentiation in Oriental River Prawn (Macrobrachium nipponense)

“…malabaricus ) using synthetic androgen during the period of ovarian differentiation [ 11 ]. Female white grouper ( E. aeneus ) can be sex-reversed to males that produce sperm and could be used to establish egg, larvae, and juvenile production in aquaculture [ 12 ]. The application of MT before the labile period of sexual differentiation can induce complete sex reversal in mandarin fish ( S. chuatsi ) [ 13 ].…”

Phylogenomic and expression analysis of Colossoma macropomum cyp19a1a and cyp19a1b and their non-classical role in tambaqui sex differentiation

“…However, none of the treatments changed the expression of esr2a and nor were able to distress the sex ratio in tambaqui. Such data is contradictory to the masculinization effect of aromatase inhibitors widely reported in a variety of fish species (Babiak et al, 2012, Shen et al, 2015, Evliyaoglu et al, 2019, Qin et al, 2020, Ayobahan et al, 2020, even at very low concentrations (Muth-Köhne et al, 2016, Joshi et al, 2019. And also incompatible to the tamoxifen effect that, acting as either agonist or antagonist, stimulating or inhibiting gonadal differentiation, leads to abnormal sexual development and biased sex ratio (Singh et al, 2012, Navarro-Martín et al, 2009, Singh et al, 2015, García-Hernández et al, 2016, Pandit et al, 2017.…”