隆线溞雄性生殖系统的组织学研究

Histology of the Male Reproductive System in Daphnia (Ctenodaphnia) carinata

隆线潘雄性生殖系统由一对精巢、一对输精管和一个雄性生殖孔组成.精巢呈腊肠形,管壁由结缔组织膜和生殖上皮构成.输精管呈细直管状,末端膨大,管壁以结缔组织膜为主.雄体的生殖细胞发生经历精原细胞、初级精母细胞、次级精母细胞、精子细胞和成熟精子五个时期.成熟精子呈棒状.精子群的发生具有同步化趋势.雄体的性成熟一般经历四个龄期.隆线溞雄性生殖系统在结构与功能上表现出相对的原始性和适应性,两者相互结合,使以隆线溞为代表的枝角类更能适应复杂多变的生活环境.

The male reproductive system of Daphnia (Ctendaphnia) carinata is composed of a pair of testes, deferens and one male gonopore. The wall of the sausage-shaped testis is composed of connective tissue and ger minal epithelium inside. The tube-shaped deferens, which gets larger at the end of it, is mainly made up of connective tissue. The spermatogenesis includes five stages: spermatogonium、 primary spermat-ocyte、 secondary spermatocyte、spermatid and spermatozoon. The mature sperm is clubbed and the spermatogenesis shows a tendency of synchronization. The sexual maturation experiences four stages. The male reproductive system retains its primitive characters on structure and function, but it has also made up its a-daptability through the long-time evolution, which enables Daphnia (Ctenodaphnia) carinata and other species of Cladocera to live with the changeable living enviro nment.