人工养殖的大黄鱼性腺发育及性周期研究

Studies on the Gonadal Development and the Annual Reproductive Cycle of the Cultured Large Yellow Croaker, Pseudosciaena crocea (Richardson)

本文描述了大黄鱼生殖细胞发生的形态特征及性腺发育规律。证实海区网箱养殖的大黄鱼可以达到性成熟。雌鱼完成第一次性周期需要3年,雄鱼则提早1年。每年4月中旬至6月,9月至10月均为大黄鱼繁殖期。雌鱼产后卵巢经恢复发育至第Ⅱ期进入越冬。翌年3—4月迅速经第Ⅲ期发育至第Ⅳ期。少部分雌鱼在秋季成熟,但都必须经人工诱导方可产卵。雄鱼精巢在大部分季节均能产生精子,越冬时发育亦处于第Ⅱ期。

During the years from 1986 to 1990, the gonadal development and the annual reproductive cycle of the Large Yellow Groaker were studied. The samples whose ages ranged from 30 days to 4 years were the same group of larvae cultured up to adult. According to the histological and cytological observation, we divided the development of the testis and the ovary into six stages, oogenesis was composed of six phases. The results showed that the fish cultured in floating net cages could reach sexual maturity. To finish the first sex cycle development, tho females needed 3 years, and the males, one year earlier than the females generally.The breeding period in which time spawning could be induced was from middle April to June and from September to October. After spawning, the resting period began with the oocytes(phase Ⅳ. Ⅴ)naturally degenerating and the primary oocytes (phase Ⅰ. Ⅱ)increasing. In winter and early spring, the histoloical structure of the ovaries returned to stage Ⅱ. They began to develop once more in middle March and attained stage Ⅳ in April. The developmental regulation of the ovaries which matured in Autumn was very complicated, which involved the problem of spawning type. In most of the seasons the sperms formed in testis. During the breeding period the spermatogenesis almost tended to synchronism. In winter the development of the testis returned to stage Ⅱ, too, but the period was shorter than that of ovary.