Electron Microscopic Study on the Spermatogenesis of Chimaera, Chimaera phantasma

Abstract

Comparing with the fine structure of spermatogenic cell of selachians and oter vertebrates, that of the chimaera was observed with light and electron microscopes. The origin of chimaera testis differed essentially from that of selachians. However the chimaera had many resemblances to the selachians in the formation of the spermatozoon, except for the following two points; first, the X organ and the axial midpiece rod of the neck were amorphous and, second, there was only one accessory on the tail flagellum.

ギンザメの精細胞の微細構造について,板鰓類並びに他の脊椎動物のそれと比較しながら,電子顕微鏡的観察を行った.精巣の起源は板鰓類のそれとは全く異なる.精子の形態は次の二点を除いて板鰓類とは多くの類似点を有する.すなわち,その相違点とは,頸部のXorganとaxial midpiece rodのいずれもが無構造であること,および尾部のアクセサリーが一つしかないことである.