锯缘青蟹精子超微结构的研究

ON ULTRASTRUCTURE OF THE SPERM OF SCYLLA SERRATA (CRUSTACEA, DECAPODA, BRACHYURA)

利用光镜和电镜观察了锯缘青蟹（Ｓｃｙｌｌａ ｓｅｒｒａｔａ）成熟精子的形态和超微结构。精子呈陀螺形，无鞭毛，在较宽的一端环生着１０余条辐射臂。精子由球状的顶体、核杯以及核衍生的辐射臂三部分组成。顶体包括顶体管和顶体囊；后者包绕在顶体管的中央管周围，并可分为头帽，亚帽带，内层和外层四个区。顶体被杯状的核包裹，仅头帽露于精子表面。成熟的精子中，位于核杯和顶体管之间的核膜出现局部断续或消失，中心粒和一些胞器出现在核杯腔中。 比较了二十多种短尾类精子的超微结构，并讨论了精子结构在分类和进化研究中的意义。

Morphology and ultrastructure of mature sperm of Scylla serrata were examined by means of light-and electron-microscopy. The mature sperm of the crab has a top-like shape with several (12-15)radial arms, but lack flagellum. The transmission microscopic observations reveal that the sperm is composed of acrosome,nuclear cup and radial arms. The spherial acrosome includes two submicroscopic structures, acrosomal tubule and acrosomal vesicle. The acrosomal vesicle surrouding the central cannal of acrosomal tubule can be divided into four zones according to their electronic denses, i. e. apical cap, subcap zone, inner layer and outer layer. The whole acrosome is embedded in a nuclear cup with only its apical cap being exposed to sperm surface. In mature sperms,which have been entered in seminal receptacle of female crab,the nuclear membrane between acrosomal tubule and nuclear cup is broken or disappears partially, and centriol, mitochondria and other organelles are located in the compartment of nuclear cup.