Studies On The Sturcture Of Spermatozoon, Spermatogenesis And Spermiogenesis Of Silurus Meridionalis Chen

From January, 2005 to January,2006, the testes of 15 heathy male Silurus meridionalis Chen collected in the Hechuan and Beibei of Jialing River and Hechuan of Fu jiang River which were sampled for histological observation under both light microscope and 4 of them were using by transmission electron microscope.The pair of mature testicular looks like oblate bag, and milk white which has some nikes on the edge of the testis.The testis was lobular type, which was typical of most teleosts. The Sertoli cell envelop the germ cells forming spermatocyts which show characteristic synchronous development. Spermatogenesis was characterized histologically, and staged according to the most advanced type of germ cell present: spermatogonia (Stage I),spermatogonia and spermatocytes (Stage II), spermatogonia, spermatocytes and spermatids (Stage III), spermatogonia, spermatocytes, spermatids and spermatozoa (Stage IV), and regressing testis(Stage V).Examined with a light microscope, the head of spermatozoa is smaller and nuclear is condensed ,the midpiece looks very unconspicuous, and the flagellum is more long. With germ cells defferent ial ,they become smaller gradually.Their diameter are (10.06±3.27) μm,(6.54±2.15) μm, (4.47±0.52) μm, (2.24±0.16) μm, respectively. Their nuclear diameter are (5.13±1.02) μm, (3.06±1.78) μm,(3.05±0.41) μm, (2.12±0.24) μm. The head length and the tail length are about (2.11±0.16) μm, (48.07 ±3.21)μm.The ultrastruture of spermatogenesis and spermiogenesis of the Silurus meridionalis were investigated by using transmission electron microscope. There are five developmental stages in the spermatogenesis, namely are primary spermatogonium, secondary spermatogonium, primary spermatocytes, secondary spermatocytes and spermatid .The spermtid develop into sperm via the process of spermiogenesis. and it developed 3 periods: early - spermtid stages, mid-spermtid stages, later-spermtids stages. At the end of develop the mature spermatozoa.The primary spermatogonium has double nuclear envelopes , and nucleonus is bigger. There are a lot of chromatoid body(CB) outside of nuclear envelopes. The mitochondrion are distributed around the...