A Morphological Study On Spermatogenesis In The Liver Fluke, Clonorchis Sinensis.

ABSTRACT

Spermatogenesis in liver flukes, C. sinensis, was investigated by using light and electron microscopes. The epithelium of the testis was composed of a basement membrane, numerous lamellae protuded from the membrance and large number of spermatogonia supported by the lamellae. The lumen of the testis was filled with numerous 8, 16 and 32-cell groups representing primary spermatocytes, secondary spermatocytes and spermatids respectively. None of cell groups with over 32 or under 8 cells was noticed. The process of spermatogenesis is presumably as follows; A cell group of 8 spermatogonia, attached together by a cytophore, is separated from the testis epithelium during the growth period, thus becoming primary spermatocytes. The primary spermatocytes divide to form a cell group of 16 secondary spermatocytes giving rise to a cell group of 32 spermatids through meiotic germ cell division. The spermatids begin to undergo a spermiogenesis. The newly formed sperms remain attached together in the lumen for a while before migrating through the vasa efferentia.