【作者】 王开顺；

【导师】 张志峰；

【作者基本信息】 中国海洋大学 ， 海洋生物学， 2004， 硕士

【摘要】 石鲽属鲽形目经济动物，本研究采用组织学和细胞学等手段研究了其性腺的发生、分化以及周年变化，为石鲽的生殖生物学研究补充内涵，同时也为其人工繁殖和资源的开发利用等提供基础数据。 采用活体拍照，对石鲽从受精卵至变态的发育过程进行了观察，描述了其发育各期的形态特征和发育速度。受精卵在(12±0.5)℃水温下，历时77h脱膜孵化，孵化后2.5d开口，孵化27d后完成变态。 采用组织学方法对室内人工培育石鲽的性腺发生与分化进行了追踪观察。结果显示：刚孵化石鲽的原生殖细胞(PGCs)数量在2个左右，位于体腔肠管与中肾管之间的背肠系膜附近，至孵化3d后数量增至8个左右，之后PGCs开始迁移。孵化9d左右PGCs分别迁移至生殖嵴处，并与生殖嵴共同构成性腺原基。性腺原基在孵化10d后的仔鱼(全长7.2mm)中最先开始形成，孵化18d后(全长8.5mm)基本形成。原始性腺在孵化40d后全长大于15mm的幼鱼中开始形成，在孵化66d后的一尾全长为32.5mm的幼鱼中最先发现有雌性分化的特征，即卵巢腔开始形成。而精巢开始分化的时间较晚，在一体长为91mm的幼鱼中最先见到雄性分化开始的特征。卵巢腔的形成方式是由性腺一端体细胞增生向另一端延伸直至两端愈合而成卵巢腔，精巢性腺分化最先出现的特征是输精导管的形成。 通过按月从市场上购买性成熟石鲽，采用组织学和电镜技术对其性腺发育的周年变化和生殖细胞发生进行了研究，我们将石鲽性腺划分为6期，Ⅰ期的性腺在雌雄鱼中都是一生只出现一次，其中的生殖细胞为卵原或者精原细胞。在每年的3月-8月期间性腺处于Ⅱ期，此期精巢中精原细胞明显增多，胞质局部可见有线状的生殖质存在，平均成熟系数为0.037％；卵巢中以2时相卵母细胞为主，可见细胞质中出现强嗜碱性的卵黄核，细胞外由一层滤泡细胞包围，但尚无放射带，平均成熟系数为1.95％。9月-10月期间性腺处于Ⅲ期，此期精巢中仍有大量精原细胞，同时可见部分精母细胞，平均成熟系数为0.086％；卵巢中以3时 石鲜孟加限加$玩印面n洲匆s性腺发生、分化及发育的周年变化相卵母细胞为主，细胞质中的卵黄核己消失，平均成熟系数为3.35%。11月性腺处于IV期，此期精巢内精细胞正处于不同的形成过程中，平均成熟系数为0.93%;卵巢中以4时相卵母细胞为主，胞质中充满染成桔红色的卵黄颗粒。卵膜增厚，形成放射带，核膜开始解体，核仁分解形成许多细小的核仁，细胞核开始向卵母细胞的一端迁移。平均成熟系数为9.37%。i2月至次年的2月间性腺处于V期，为其生殖季节。此期精巢内充满精子，平均成熟系数为1.97%;卵巢中以5时相卵母细胞为主，核膜溶解，生殖细胞开始游离于卵巢腔中，平均成熟系数为26.78%。更多还原

【Abstract】 Stone flounder (Kareius bicoloratus) is a high-value flatfish prized by commercial fishers. The ontogenesis, differentiation and developmental annual change of gonad in K. bicoloratus were studied by histological and cytological methods in this research. The results will provide basic biological data for reproductive biology of K. bicoloratus. This information is useful for commercial stone flounder culture.The morphological characteristic and development speed of embryos and larvae in K. bicoloratus have been studied by photographed alive. Fertilized eggs hatch out at about 77 h post fertilization (HPF) at (12?.5) . Mouth opens at 2.5 d, and metamorphosis Is compIetecTaTabbut 27 d after Hatching (DAH)A systemic study on the gonadal ontogenesis and differentiation in K. bicoloratus raised in an aquaculture plant has been made through histological methods. The results show that there are about 2 primordial germ cells (PGCs) present in the newly hatched larva, and are located between the gut and the mesonephric duct. After the mitotic proliferation the number of PGCs increases to about 8. Then PGCs migrate to the genital ridge. In larva 9 days after hatching (DAH) PGCs reach the germinal ridge and begin to form the gonadal rudiment together. Gonadal rudiment begins to form in a larva 10 DAH, which is 7.2mm total length (TL), and completes at about 18 DAH (larva is 8.5mm TL). The primordial gonad starts to be form in a 15mm TL larva 40 DAH. And the presence of an ovarian cavity, an early sign of female sex differentiation, is first seen in stone flounder 32.5mm TL 66DAH. In presumptive testis the differentiation is late, and is found in a 91mm TL fish. The form of ovarian cavity is begun with an aggregation of somatic cells in one side of the primordial gonad, then extends to the other side of it and eventually fuse together to form anarrow ovarian cavity. The testicular differentiation character is the formation of the tubules leading to the sperm duct.The annual change of gonad development and the ontogenesis of germ cells in Kareius bicoloratus have been studied by using histological methods and electronic microscope. The samples were bought from the market monthly. The gonadal development can be divided into six stages. Stage I of both male and female stone flounder appears only once in all its life, and the germ cells are comprised by spermatogonia or oogonia. The gonad from Mar to Aug keeps at stage II. The gonad index (GI) of testis at this stage is 0.037%, and the amount of spermatogonia is increased quickly. There is some linear germ plasm in the cytoplasm of spermatogina. In ovary at this stage it is mostly composed by oocyte of phase 2 which the character is the appearance of yolk nucleus, and no zona radiate in membrane. The mean GI of ovary is 1.95%. From Sep to Oct gonad is at stage III which testis is composed by lots of spermatogina and few spermatocytes, and the mean GI of testis at this stage is 0.086%. In ovary the ooctyes at phase 3 are in dominate position, the yolk nucleus disappear. And the GI of this stage is 3.35%. Both testis and ovary are at stage IV in Nov. hi testis the germ cells are in spermiogenesis, and the mean GI is 0.93%. hi ovary the oocytes are mostly at phase 4, which are filled in the cytoplasm with vitellin granule, and the zona radiate in membrane begins to formation. Nucleus moves to one side of the oocyte gradually. The mean GI of ovary at this stage is 9.37%. The reproductive season of stone flounder is between Dec and Feb, and during this period the GI is the highest in a year, 1.97% in testis and 26.78% in ovary respectively, and the gonad stage was at stage V. The testis is filled with spermatozoa, and the ovary is composed by oocytes at phase 5. The oocytes are dissociated in the ovary cavity, and the nucleus membranes begin to dissolve.更多还原