湛江地区光裸星虫的生殖细胞发育和生殖周期

Development of Germ Cells and Reproductive Cycle of Sipunculus nudus L in Zhanjiang

采用活体观察和常规石蜡切片技术对湛江地区光裸星虫生殖周期、生殖细胞的发育及形态结构进行研究.结果表明:星虫雌雄异体,无肉眼可见生殖腺结构,原生殖细胞在体腔液中发育;雌性生殖细胞根据其卵膜的形成和卵黄积累情况可以分为4个发育阶段,小生长期、大生长期、成熟前期和成熟期;雄性生殖细胞也分为增殖期、生长期、成熟期和变态期4个阶段;成熟的生殖细胞经肾管排出体外.生殖季节为5～9月,其中7～8月为高峰期.

Studies were carried out on the reproductive cycle and the development of germ cells of Sipunculus nudus by histological technique in this paper. The results show that the animal is dioecious. Gonad cannot be found in the Sipunculus nudus during one-year observation. The dissociated germ cells multiply and develop in the coelomic cavity. The development of oocyte can be divided into four stages: small-growth, largegrowth, pre-mature and mature stage. Whereas, that of the germs of male includes four stages as well: multiplication, growth, maturity and metamorphogenesis stage. The mutiplication season of the S. nudus is from May to September, and the peak appears in July and August. The mature germ cells move outside throught nephridia.