利用透射电镜观察大竹蛏(Solen grandis Dunker)精子发生和精子的超微结构，描述了从精原细胞发育到成熟精子过程中超微结构的变化。大竹蛏精子发生历经精原细胞、初级精母细胞、次级精母细胞、精细胞和成熟精子5个阶段。成熟精子属典型的原生型，全长52—57 μm，由头部、中段和尾部三部分组成。头部由顶体和细胞核组成；中段由4—5个椭圆形线粒体和2个相互垂直的中心粒组成；尾部细长，为典型的“9+2”型结构。大竹蛏与同属的长竹蛏精子发生和精子超微结构存在差异。大竹蛏精细胞前顶体囊的高电子密度物质分布在周缘呈一个带缺口的弧形而不是圆形，而长竹蛏前顶体囊周缘的高电子密度物质呈一圆形分布；大竹蛏的前顶体囊是先内凹变形，然后一边变形一边移动，而长竹蛏的前顶体囊是在到达核前端后才开始变形。大竹蛏的顶体比长竹蛏的稍长；大竹蛏精子核形似子弹头而长竹蛏精子核形为圆球状；大竹蛏有卫星体结构而长竹蛏无卫星体结构；大竹蛏精子尾部鞭毛比长竹蛏的长。结果可以为竹蛏科相似种类的鉴定及亲缘关系的探讨提供参考依据。

The ultrastructure of spermatogenesis and spermatozoon of Solen grandis was observed by transmission electronic microscope. The results showed ultrastructural changes from spermatogonium to spermatozoa. The spermatogenesis of Solen grandis included five stages: spermatogonium, spermatocyteⅠ, spermatocyteⅡ, spermatid and spermatozoon. The spermatozoon, of a typical primitive type (52—57 μm), consisted of a head, a middle piece and a tail. The head comprised of a bowl-shaped acrosome and a warhead-shaped nuclear. Four or five ellipsoidal mitochondria and two centrioles made up the middle piece. The tail was thin but long, with a typical structure as type “9+2.” The distinctions of spermatogenesis and sperm morphology between Solen grandis and Solen strictus were also discussed. High-density material lying at the circumference of a proacrosomal vesicle was arched with a gap in Solen grandis, but round in Solen strictus. From this gap a proacrosomal vesicle of Solen grandis began to invaginate and deform while it moved to the nuclear front. However a proacrosomal vesicle of Solen strictus did not deform until it reached the nuclear front. Solen grandis was longer than Solen strictus. The nuclear of Solen grandis was warhead-shaped while one of Solen strictus’s was spherical. A satellite body was found in Solen grandis but not in Solen strictus. In addition, Solen grandis had a longer tail than Solen strictus. The results can provide reference for identification and genetic relationship analysis of Solenidae.