文献类型： 外文期刊

作者： Liu, M. ¹ ; Wang, Y. -Y. ¹ ; Shan, X. -J. ² ; Kang, B. ³ ; Ding, S. -X. ¹ ;

作者机构： 1.Xiamen Univ, Coll Ocean & Earth Sci, State Key Lab Marine Environm Sci, Xiamen 361102, Fujian, Peoples R China

2.Chinese Acad Fishery Sci, Yellow Sea Fisheries Res Inst, Shandong Prov Key Lab Fishery Res & Ecol Environm, Qingdao 266071, Shandong, Peoples R China

3.Jimei Univ, Coll Fisheries, Xiamen 361021, Fujian, Peoples R China

关键词： bisexual;Epinephelidae;primary male;sequential hermaphroditism;sexual differentiation

期刊名称：JOURNAL OF FISH BIOLOGY （ 影响因子：2.051； 五年影响因子：2.25 ）

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收录情况： SCI

摘要： Gonad ontogeny of the Hong Kong grouper Epinephelus akaara (a bi-directional sex changer) and the yellow grouper Epinephelus awoara (a protogynous hermaphrodite) was examined for the first time from post-larval phase until first sexual maturation, by histology. Approximately 20 specimens of each species were collected randomly every 2-7weeks from rearing tanks with natural sea water and temperature between June 2013 and June 2014. The paired gonadal primordia (GP) were observed at 6weeks after hatching (wah) for both species; however, gonia were first observed in GP at 16wah for E. akaara and at 8wah for E. awoara. The timings for the appearance of primary-growth stage oocytes (O1) and the completion of ovarian lumen (OL) varied; both at 27wah for E. akaara, and at 18 and 23wah for E. awoara respectively. A bisexual-phase gonad with an OL, O1 and scattered spermatogenic cysts (SC) was observed at 27-29wah for both E. akaara and E. awoara. Sexual differentiation was subsequently observed from the bisexual-phase gonad at 34wah for E. akaara, and 41wah for E. awoara, with the appearance of cortical-alveolus stage oocytes (O2) for developing female and the proliferation of SC for developing primary male (i.e. from juvenile directly). Ovaries of mature females contained the vitellogenic stage oocytes (O3) and scattered SC; testes of mature primary males had sperm in sperm sinuses within the gonadal wall and remained O1. Minimum age of first sexual maturation for both female and primary male of E. akaara was at 41wah; minimum total length (L-T) of female (143mm) was larger than that of primary male (137mm L-T). Minimum age and size of first sexual maturation for female of E. awoara (47wah and 149mm L-T, respectively) were larger than those of E. akaara. Developing primary males of E. awoara were found at 41-58wah, however, mature males were not observed, indicating inconsistency in first sexual maturation for E. awoara. This study provided strong evidences of primary male pathway in E. akaara and E. awoara; the latter is confirmed to be diandric. (C) 2016 The Fisheries Society of the British Isles