日本沼虾生精细胞核的形态变化及其在真虾部Caridea生殖进化中的地位

应用透射电镜（ＴＥＭ）技术研究了日本沼虾精子发生过程中细胞核的形态变异。生精细胞的核经历了由圆形或椭圆形变为浅碟状的一系列变化过程；其核膜由原来的完整变为不完整，成熟精子仅在精子尾部具有核膜；核内染色质由松散逐渐聚合分化，在成熟精子核内形成了泡状和丝状两种形态的核物质。精子具备泡状和丝状两种核物质是日本沼虾的重要特征之一。精核的形态可以作为十足类甲壳动物的重要分类依据；研究精子发生过程中细胞核的形

Morphological variation of spermatogenic cell nucleus in M a crobrachium nipponense(de Haan) and its status during reproductive evolution of Caridea

The morphological variation of nucleus during spermatogenesis in Macrobrachium nipponense and its status during the reproductive evolution of Caridean shrimp were investigated using transmission electron microscopy(TEM) technique. During the whole process of spermatogenesis, the nuclear morphology of spermatogenic cell varied from spherical or ellipsoidal to shallow dish like shape,and the nuclear membrane existed only in the rear part of mature sperm varied from intact to unintegrated one. The chromatin gradually varied from loosen to coacervative one, and then,developed differentially into two types of nucleus in the mature sperm,i.e.,vesicular nucleus and filamental nucleus, which became an important characteristics of Macrobrachium nipponense .These nuclear morphological variations could be regarded as an important classifying property among Decapoda, on which,studies could contribute much to the analysis of the status of this species in the reproductive evolution of Caridean shrimp.