Histology of vas deferens and formation of spermatophore in prawn Metapenaeus ensis

The Metapenaeus ensis individuals were collected from Fujian coastal areas, body length 14 cm. The samples were observed under Olympus BH 2 microscope after vivisection,routine fixation and wax embedment. The results show that the reproductive duct of M. ensis consists of anterior vas deferens,middle vas deferens,posterior vas deferens and seminal vesicle. The epithelium of anterior vas deferens is columnar and its secretion is basophily. The forepart of the middle vas deferens is high columnar epithelium and the rear end is columnar epithelium. The secretion of the middle vas deferens is acidophily. The structure of the posterior vas deferens is similar to that of the middle vas deferens,but its diameter is shorter than that of the middle vas deferens. The seminal vesicle has three lumina with one spermatophore. The spermatophore consists of sperm mass and spermatophore wall which is divided into two layers-inner layer and outer layer with the sperm mass in the middle of the inner layer. The inner layer is called primary spermatophore wall which is homogeneous and basophily. The outer layer is called secondary spermatophore wall which is acidophily and partly encloses the primary spermatophore wall. The transvers section of the spermatophore is willow leaf shaped and is divided into smooth zone which is enclosed by the secondary spermatophore wall and corrugate zone which is composed of primary spermatophore wall. The spermatophore formed in the posterior region of the middle vas defrerens,is the product of the secretions of anterior vas deferens,middle vas deferens and secretory tube by complex chemical changes.