Crude Lip Catfish Gonad Histology And Ultrastructural Study

The testis of Leiocassis crassilabris Gunther presents the comb form, stretching out a flat form branch outwardly, each side of the branch can reach to 20-30.The female and male compares to 1:2-3. The bisexual fish body all presents Huang green, breed the season body color is a yellow, the female is opposite smaller and thin long, the male fish is robust and emollient. The mature female's belly swellow greatly soft and full of flexibility, it is obvious ovary in form, and egg grain can be seen when belly is pressed lhightly.The male fish belly thin long,sharp and long, present a white, usually, semen could not extrude easily. Spermatogenesis passes through the following stages that are primary spermatogonium, secondary spermatogonium, primary spermatocyte, secondary spermatocyte and spermatid then becomes mature sperm. The primary spermatogoniums are spermatogenic stem cells, spermatogenic cells of latter stages are derived from it by division. It has the biggest volme in all spermatogenic cells and distributes separately. It has a weak- alkalophilic nuclus, with an apparent nucleoli and very low-electron-densed chromatin. An abundance of mitochondria in the cytoplasm always have few cristae, and the electron dense of the matrix is low. There are lots of chromatoid bodies in the cytoplasm too. The spermatids undergo all the changes of spermiogenesis, such as the flagellum formed, nucleus condensed, and the mitochomdria enter into the sleeve, and so on. The flagellum lies on one side of the nucleus, where the implantation fossa is formed by invagination of nuclear membrane. The centriolar complex is in the implantation fossa. The proximal centriole is perpendicular to the basal body. As spermiogenesis proceeds, flagellum formed earlier than nucleus condensed of the spermatid. Another special phenomenon appears in the development of the spermatid, there are many transient granules produced in the cytoplasm. Subsequently, the number of these granules decreases gradually and disappear in the sperrmatid near mature, the function of these granules is not clear.The oogenesis also can be divided into phrases I-VI according to the following characters: the size of oocyte, the number and volum of nucleolus, the change of karyoplasms and karyothec, the appearance and change of yolk nucleolus in cytoplasm, the distribution of granulose cell, vacuole, and yolk granule as well as the histological traits of the components and change of follicle cell. This paper reports phrases I-VI. As for the phrase I, Most of the cells are round with one nucleolus which is prone to absorbing alkali and has the big ratio of nucleus to cytoplasm. In the phrase II, the distinctive traits are as follows: oocyte goes into the small growth stage; the number and volume of oocyte get bigger and bigger; the ovarian wall forms spawning plates which comes to shape, and its plasma is the silk shape. As for the phrase III, the vacuole extends to the area of nucleolus till it fills cytoplasm; the yolk granules extend with the movement of vacuole. The yolk granules have different morphological structure in different areas; the big nucleolus is different from those little ones, and there is also excluding phenomenon of karyoplasm. The ability of absorbing acid of cytoplasm becomes stronger. Cytoplasm only appears in the area of cortical layer. The vacuole and yolk granules are filled in the cytoplasm; in the middle period of this phrase, zone radiata appears; there are many capillaries appear among the oocytes; follicular cells increase and form one layer flat follicle cells. As for the phrase IV, vacuole begins to degenerate and its number decreases, while yolk granules begin to fill the cytoplasm. Yolk granule has the tendency to conjugate together; some nucleolus membrane disappears and diffuses into cytoplasm; there are many nucleoli in small volume; zone radiata gets thicker and its channel become very apparent; follicular layer differentiate into two layers. The inner layer has granulose cell and the outer one has thecal cell.The testicular and overy structure, cycle development and spermatogenesis of the Leiocassis crassilabris Gunther have been studied at microscopic and submicroscopic levels in this thesis.