title: Androgens stimulate sex change in protogynous grouper, Epinephelus coioides: spawning performance in sex-changed males.
abstract: We examined the efficacy of androgens (1.0 mg/kg body mass), testosterone (T), 11-ketotestosterone (11-KT), 17alpha-methyltestosterone (MT), testosterone propionate (TP) or androgen mixture (T, MT and TP in an equal ratio), for induction of sex change in protogynous orange-spotted grouper, Epinephelus coioides. The spawning performance in sex-changed males was also investigated. MT and androgen mixture at a dose of 1.0 mg/kg BW induced a sex transition and completion of spermatogenesis up to the functional male phase. The androgen mixture was most effective. Significantly, higher plasma T levels were found in MT and androgen mixture groups compared to control and other androgen implantation (T, TP or 11-KT) groups. We found that plasma levels of estradiol-17beta (E2) or 11-KT were not different among treated groups. Sex-changed males could successfully fertilize mature eggs. Fertilization and hatching rates were of 23.5-70.4% and 8.4-44.6%, respectively. The data demonstrated that induction of sex change by exogenous androgens in groups could apply to the aquaculture field for seed production.
authors.affiliation: Department of Aquaculture, National Taiwan Ocean University, Keelung 202, Taiwan, ROC.
authors.forename: Shinn-Lih
authors.initials: SL
authors.lastname: Yeh
authors.forename: Ching-Ming
authors.initials: CM
authors.lastname: Kuo
authors.forename: Yun-Yuan
authors.initials: YY
authors.lastname: Ting
authors.forename: Ching-Fong
authors.initials: CF
authors.lastname: Chang
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D005260:Female; D005306:Fertilization / Q000187:drug effects* / Q000502:physiology; D057850:Hermaphroditic Organisms; D008297:Male; D009865:Oocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D010473:Perciformes / Q000502:physiology*; D012727:Sex Characteristics; D019849:Sex Determination Processes; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects / Q000502:physiology
chemical_list: D000728:Androgens