广东鲂性腺发育组织学研究

A histological study on gonadal development of black amur bream(Megalobrama terminalis)

利用组织学方法,对珠江下游野生广东鲂(Megalobrama terminalis)性腺进行了显微观察和研究,描述了其卵巢、精巢的结构特征以及各类型生殖细胞形态。结果显示,广东鲂属于一次性产卵类型,卵巢发育类型为部分同步型。其卵巢为细线或条状,卵巢发育经历卵原细胞期、单层滤泡细胞期、卵黄泡期、卵黄充满期、成熟期和退化期。卵细胞发生经历3个阶段:卵原细胞、初级卵母细胞和次级卵母细胞;卵巢初级卵母细胞中核仁外排现象出现在第2时相末期至第3时相早期;精巢呈线状或直棒状,精巢为叶状型结构。精细胞发生经历5个阶段:精原细胞、初级精母细胞、次级精母细胞、精子细胞及精子;繁殖季节精子充满于精小叶内,精小囊消失。

We used histological methods to observe the gonadal development of Megalobrama terminalis , and decribed the morphology in each type of germ cell and structural feature in ovary and testis. The results indicate that M. terminalis is a one-time spawning type fish, whose ovary development type is partially synchronous. The ovary was thin or flat. The ovarian development had oogonia, monolayer follicular phase, yolk vesicle phase, yolk filling phase, maturation phase and degeneration phase. Occurrence of oocytes had undergone three stages: oogonia, primary oocytes and secondary oocytes. The nucleolar efflux phenomenon occurred in the primary oocytes of ovary from the late Stage Ⅱ to the early Stage Ⅲ. The testis was thin or straight with a leaflet structure. The spermatogenesis had undergone five stages: spermatogonia, primary spermatocyte, secondary spermatocyte, spermatid and sperm. The spermatids were filled with spermatozoa and the spermatic capsules disappearred in breeding season.