| 摘要: |
| 运用组织学方法对牙鲆(Paralichthys olivaceus)的性腺分化和发育过程进行了观察。结果表明，牙鲆的性腺发育可分为3个阶段，即原始性腺阶段、性腺分化阶段和性腺分化后阶段。培育水温为18℃～20℃下，孵化后第45天、平均全长为22.0 mm±2.8 mm的牙鲆，其性腺分化尚未开始，属于原始性腺。70日龄、平均全长为38.0 mm±1.7 mm的牙鲆，部分个体中观察到卵巢的雏形，其余个体中性腺变化并不大；到了第110天、平均全长达到86.5 mm±5.9 mm时，雌性个体卵巢的卵巢腔进一步增大，并出现卵原细胞向卵母细胞的转变。精巢的分化开始于90日龄、平均全长为63.5 mm±3.4 mm的幼鱼，此期精原细胞快速增殖，体细胞进行有丝分裂并逐渐形成输精管原基；进一步的细胞学分化则出现在100日龄、平均全长为76.0 mm±8.6 mm的个体中，此时可以看到精小叶的形成；在平均全长为140.0 mm±15.2 mm时，精巢中出现初级精母细胞，标志着性腺分化的基本完成。 |
| 关键词: 牙鲆(Paralichthys olivaceus) 性腺分化 组织学 |
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| 基金项目:国家863计划重大项目（2006AA10A404）；国家自然科学基金资助项目（30571445） |
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| Histological evaluation of gonadal differentiation in olive flounder (Paralichthys olivaceus) |
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| Abstract: |
| Gonadal differentiation and development in olive flounder (Paralichthys olivaceus) were studied by histological observation. A gonad development process could be divided into three phrases, i.e., primary gonad stage, gonadal differentiation stage and post-differentiation stage. When fish were raised at temperature of 18～20℃, gonad formed and remained undifferentiated till the 45th day post hatching (D45). When juveniles reached about 38.0±1.7 mm of mean total length (TL) on the D70, ovarian cavity was observed in presumptive ovary. On the D110, when mean total length reached about 86.5±5.9 mm, ovarian cavity grew bigger, and oocytes were firstly detected. Differentiation of testis was firstly observed in juvenile flounder with mean total length of 63.5±3.4 mm on the D90, when spermatogenous cell proliferated rapidly and spermaduct formed. Seminal lobule appeared on the D100 when juveniles reached about 76.0 mm of total length. And when flounders reached total length about 140.0 mm, appearance of spermatocyte indicated the completion of gonadal sex differentiation. |
| Key words: Paralichthys olivaceus gonadal differentiation histology |
