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本文利用组织切片的方法研究了双单倍体牙鲆的性腺发生、性别分化及早期发育。结果显示:双单倍体牙鲆中除雌性外,还有雄性和未分化鱼出现,所占比例分别为56%、38%和6%。双单倍体牙鲆雌性的性别分化晚于普通牙鲆。雌鱼至100日龄,卵巢腔仍未闭合;110日龄雌鱼的产卵板上存在大量向卵母过渡的卵原细胞,未见Ⅰ时相卵母细胞出现。双单倍体牙鲆雄鱼精巢的分化在时间上和普通牙鲆的基本相同。随着发育的进行,双单倍体牙鲆雌鱼的卵巢出现部分异常的卵母细胞以及卵巢退化现象;部分雄鱼的精巢也有退化现象出现。9～11月龄,双单倍体牙鲆雄鱼的精巢发育到Ⅲ期,而普通牙鲆性腺在同期进入了Ⅳ期;11月龄开始双单倍体牙鲆雄鱼精巢有退化的迹象;13～15月龄,精巢退化成精小叶,其中只含有精原细胞,初级精母细胞消失不见,似Ⅱ期精巢。
In this paper, the histological sections were used to study the gonadal occurrence, sex differentiation and early development of double-haploid flounder. The results showed that in addition to the female, there were male and undifferentiated fish in the double haploid flounder, accounting for 56%, 38% and 6% respectively. Double haploid Japanese flounder female sex differentiation later than the common flounder. Females to 100 days of age, the ovarian cavity has not closed; 110 days old laying eggs on the ovum there is a large number of transition to the oogonium oocytes, no oocytes appeared. The differentiation of male double-haploid flounder testis was similar to that of common flounder in time. As the development proceeds, some abnormal oocytes and ovarian degeneration occur in the ovary of the double-haploid P. virgata; some of the male testis also degenerate. At 9 to 11 months of age, the testis of double haploid P. mandarinus developed to stage Ⅲ, while the gonads of common Japanese flounder entered stage Ⅳ in the same period. The testis showed signs of degeneration in double haploid P. mandarinus at 11 months of age ; 13 to 15 months of age, sperm degeneration into sperm cells, which contain only spermatogonia, primary spermatocytes disappear, like Ⅱ stage of the testis.