南方鲇的繁殖生物学研究：性腺发育及周年变化

依形态学特征将南方鲇性腺的发育分为６个时期，据组织学特点将雌雄性细胞的变化各分为６个时相，幼鱼的精原细胞经历时间比卵原细胞长；发育的早期和中期，精母细胞的发育速度不同步，但到晚期则趋于同步化，３时相卵母细胞仍有卵黄核，大，小核仁数随卵母细胞的发育而变化，精孔细胞和卵胶膜源于滤泡细胞，雌雄鱼成熟年龄均为３龄，繁殖期３－５月，一次产卵类型，繁殖时不能将卵完全产出。

REPRODUCTIVE BIOLOGY OF SILURUS MERIDIONALIS CHEN:THE DEVELOPMENT AND ANNUAL CHANGE IN THE GONADS

This paper describes the morphology, histology and annual cyclical changes of gonads in Silurus meridionalis Chen collected from the lower reaches of the Jialing River. According to the morphological and histological features, the development of gonads can be divided into six stages and the change of germ cells of male and female can be divided into six phases. The duration of spermatogenous cells in the male larvae is longer than the ovogonia in the female. The spermatocytes develop at different rates during the early and middle stages, but in the later the development of all the cells becomes synchronized. The oocyte of early phase 3 has a yolk n ucleus too. Many nucleon which can be divided into 2 types i.e. large and small, are observed in oocytes. The number of the nucleon changes with the oocyte development. The micropylar cell and the stick membrance of the egg are derived from the follicular cells. The maturation age of male and female are 3 years old. The spawning period lasts from March to May. The results of this paper indicate that this fish spawns only once a year, and not all of mature eggs in the ovary can be laid out during spawning.