可口革囊星虫的精子发生和精子结构.pdf

53(4) : 733- 741, 2007 Acta Zoologica Sinica * 1, 2,3** 2** 1, 3 1,3 竺俊全 王 武 许式见 曾海祥 1 , 315211 2 , 200090 3 , 315211 ( Phascolosoma esculenta) , , , , , , ; , , , , 6 ( 5 7 ) ; , , 9+ 2 : : ! ; ∀ , ; # , ; ∃ , [ 53 (4) : 733- 741, 2007] Spermatogenesis and sperm morphology of Phascolosoma esculenta 1, 2, 3** 2** 1,3 1, 3 ZHU J nQ an , WANG W , XU ShiJian , ZENG HaiXiang 1Fac lty of Life Sciences and Biotechnology, Ningbo University, Ningbo 315211, Zhejiang, China 2 College of Aq aLife Science andTechnology, Shanghai Fisheries University, Shanghai 200090, China 3Key Laboratory of Applied Marine Biotechnology by the Ministry of Ed cation, Ningbo University, Ningbo 315211, Zhejiang, China Abstract The characteristics of spermatogenesis and sperm str ct re were investigated in Phascolosoma esculenta by means of light and electron microscopy. The testis is a narrow band of tiss e sit ated at the base of the ventral retractor m scles. Cells at vario s stages of spermatogenesis ( incl ding spermatogonia, spermatocytes and spermatids) are readily identifiable in the mat re testis. Early in spermiogenesis, a spermatid mass is shed into the coelom. Spermatozoa develop within the spermatid mass, and then enter the nephridi m. Each mat re sperm consists of a head and a tail. The head incl des a conical acrosome and contains a dr mshaped n cle s. The rear part of the acrosome is wrapped aro nd the anterior portion of the sperm n cle s. The acrosome comprises three layers ( exterior, interim and interior layers) . The exterior layer contains radiate septa. An