Sex discrimination of cultured greater amberjack Seriola dumerili using steroid hormones

Sex differentiation and early sex identification in hatchery produced greater amberjack (Seriola dumerili) reared in sea cages

“…Moreover, using Cytochrome P450 17 A (cyp17α1) knockout zebra sh, it was shown that androgens are essential for male brain sex differentiation (Shu et al 2020). In greater amberjack, 11-KT has been used as a sex-identifying hormone, as its plasma values are a lot higher in males (Aoki et al 2019). The role of 11-KT in female sex differentiation remains unclear; however, recent studies in different species have revealed a role for this hormone in oocyte size increase and lipid accumulation (Akhavan et al 2019;Lokman et al 2007;Wang et al 2020).…”

“…Sex identi cation in sh is a rather complicated process, as sh do not possess sex-speci c external characteristics; identifying sh sex, however, is very useful for aquaculture purposes and different methods for sex recognition have been suggested, with the 11-KT/E 2 ratio being the most common (Baroiller et al 1999). In the greater amberjack, observation of external urogenital pore characteristics (Smith et al 2014) and 11-KT concentration (Aoki et al 2019) have been suggested as non-invasive methods for sex identi cation. However, the rst method is more applicable in sh larger than 50 cm fork length (FL), whereas the latter was conducted in sh older than 412 dph and larger than 39 cm FL.…”

Seasonal changes of plasma sex steroids in captive longtooth grouper Epinephelus bruneus (Bloch) in subtropical regions

“…Tagged fish with confirmed spermiation in this study was assigned as male and the others temporally as female. In case an individual with no spermiation and was inferred as female from the E2 levels during the early period of the study but later showed the 11-KT levels comparable with the male and released semen, the fish was assigned as a sex-reversal fish (Aoki et al, 2020;McGarvey et al, 2020).…”

“…Sex steroid hormones are reliable indicators to assess the sexual differentiation and reproductive maturity in fish (Aoki et al, 2020;McGarvey et al, 2020). In females of teleost fish, the folliclestimulating hormone (FSH) is responsible for the stimulation of thecal and granulosa cells to produce estradiol 17β (E2), the key hormone that induces the liver to synthesize vitellogenin, which is incorporated into the oocyte during vitellogenesis (Farias et al, 2021;Lubzens et al, 2010;Mylonas & Zohar, 2001;Nagahama, 1994).…”