Journal of Dalian Ocean University  2008, Vol. 23 Issue (6): 451-454 DOI: 10.3969/j.issn.1000-9957.2008.06.008 |
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| Histological observation of gonadal differentiation in cultured Japanese flounder Paralichthys olivaceus |
| SUN Zhao-hui , LIU Hai-jin, SI Fei, WANG Yu-fen, JIANG Xiu-feng
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| 1. College of Animal Science and Technology, Northeast Agricultural University, Harbin 150030, China; 2. Chinese Academy of Fishery Sciences, Beijing 100039, China; 3. School of Life Science and Technology, Dalian Fisheries University, Dalian 116023, China;4. Beidaihe Central Experiment Station, Chinese Academy of Fishery Science, Qinhuangdao 066100, China |
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Abstract The occurrence, process and histological characteristics of gonadal differentiation were histologically observed in Japanese flounder Paralichthys olivaceus. One elliptical primordinal germ cell （PGC） was observed by the 10th day posthatching（dph） （4.2 mm in total length）. On the 20th dph （6.6 mm TL）, the gonad anlage emerged, and remained undifferentiated by 30th dph （9.7 mm TL）. The anlage of the efferent duct was found on the 50th dph （23.8 mm TL）. On the 65th dph （47.5 mm TL）, the dorsal and ventral edges of the gonads began to extend laterally and eventually fused to form the presumptive ovarian cavities along the lateral sides of the gonads. The spermatogonia were first recognized in the testis on the 85th dph （84.3 mm TL） and oocytes in early meiosis were first observed from the 105th dph ovary （124.5 mm TL）, indicating that the sex differentiation is evident distinctness between female and male. The differentiation occurred earlier in male than in female.
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Published: 30 December 2016
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