【作者】 高艳丽；

【导师】 华育平；

【作者基本信息】 东北林业大学 ， 野生动植物保护与利用， 2006， 博士

【摘要】 施氏鲟是黑龙江特有的经济鱼类，目前已成为重要的养殖品种。鲟鱼最有价值的产品是鱼子酱，随着养殖技术的提高和生产规模的扩大，通过人工养殖获得鲟鱼子酱已成必然趋势。对施氏鲟性腺发育和性别控制的研究，是解决鲟鱼养殖过程中人工繁育和全雌化生产的基础和必要手段。本文采用组织学、生物化学及放射免疫学等方法，对不同发育时期施氏鲟的性腺组织、外源性激素诱导后血液和组织中性类固醇激素、及雌性化比率进行观察和测定，同时也探讨了人工养殖条件下施氏鲟的雌雄比率。 人工养殖条件下，施氏鲟血液中睾酮（Testosterone，T）的含量随着年龄增长而增加，从1龄到4龄T含量是处于上升状态，到5龄时表现了下降趋势。雌二醇（17β-estradiol，E₂）与T含量有所不同，在1龄时维持较低水平，到2龄时仍保持较低的水平，2～4龄E₂水平缓慢上升，4～5龄E₂水平快速上升。雌性亲鱼可达到904pmol1·L^-1，雄性亲鱼的E₂水平维持在较低的水平内。 施氏鲟性成熟晚，性腺发育时间较长，雌鱼成熟需9～11年，雄鱼则为6～7年，而人工养殖的雌鱼性成熟提前1～2年。鱼苗出膜12天，在其肾管区下方可见有一棒状突起，由上皮细胞构成，为生殖腺原基。至六月龄时性腺切片可见原始生殖细胞进行有丝分裂，分裂后发育为性原细胞，但在显微镜下无法判断其雌雄。七月龄后显微镜下可以看到不同性别性腺结构某些特征，组织学可以观察到明显卵巢结构和精巢结构。性腺二期是性腺中脂肪大量积累的阶段，同时也出现了大量的初级性母细胞，此阶段发育时间较长，可长至数年。性腺三期性腺增生较快，脂肪消耗的速度加快，性腺重量明显增加，横切面上性腺组织面积扩大。精巢外型展开为两端尖细的长梭形，淡红色、黄色或上有青色斑，由鳔前1／3处至泄殖腔前。卵巢中脂肪消耗较快，色素和脂肪集中于卵巢中、侧部，性腺组织上分散血管，性腺细胞贴附在脂肪上，脂肪裹着性腺组织，后者呈橘瓣状或指状交叉重叠。性腺四期雌雄性腺极易分辨，已接近生理成熟。精巢还残存着一些脂肪，上面分布大量血管使整个精巢呈粉红色，此时表面可见精子，输精管变粗，内已有少量的精子。卵巢体积很大且脂肪全部消失，剖开腹壁及可见到有透明薄膜包裹的大量的卵细胞，卵细胞长轴直径在2.5～4mm之间。性腺五期鱼体腹部胀大而松软，此时性腺达到生殖成熟。轻按腹部有泄殖孔流出乳白色的精液或黑褐色的卵。性腺六期为退化期，其内的发育成熟的性腺细胞被排出或自然吸收。卵巢体积因产卵而显著减小，颜色暗淡，松软萎缩，其内残留滤泡和第Ⅳ、Ⅴ时相的卵母细胞，它们很快被卵巢吸收退化，形成半透明、桔黄色的不规则结构。生殖后的精巢，体积缩小，外观萎瘪，经恢复后转为Ⅱ期。 通过电镜观察的施氏鲟卵巢中卵原细胞核常染色质较多，异染色质呈浅月牙形在核一侧，核膜完整。胞质中大量的腊肠状或蚕豆状的线粒体，在脂肪之间和血管附近弥散大量的梅花状的糖原，一些糖原趋近卵原细胞，并能看到糖原向胞核处运输。更多还原

【Abstract】 Amur sturgeon is endemic economic fish in Heilongjiang River and become important culture fish at present. The studies on gonad and sex control in Amur sturgeon are necessary for artificial propagation and breeding and hologynic production in the process of sturgeon cultivation. Using histological, biochemical and radioimmunologic methods, this article observed the gonads in different decelopment periods and determined the blood and tissue sex steroid hormone and feminination ratio after sex control, and investigated the proportion of cultured female and male.Under the condition of artificial cultivation, the serum level of testosterone （T） in Amur sturgeon increased following the age from 1-year to 4-year and began to decrease at 5-year. In contrast, the serum level of estradiol-17 β （E2） was constantly low during 1-year and much lower at 2-year, then increased slowly until 4-year, at 5-year it increased rapidly and reached 904pmol·L^-1 in female but kept low level in male.Sexual maturation is late and the period of gonad development is long in Amur sturgeon. The female need 9¹1 years and the male need 6⁷ years while the cultured female 1-2 years earlier. The primordial gonad, genital fold which composed of epithelial cells formed below the nephridium area 12 days after hatching. When fish was 6 months old, primordial germ cells had mitosis and became gonium. The gonad still not sex differentiate at that time. At the age of 7 months some structural features in different sex gonad could be observed by microscope so the testis and ovary could be distinguished. At the second stage the fat was accumulating a lot, and a large number of auxocyte had emerged. This period lasted a long time to several years. At the third stage the gonad grew fast so the weight of it increased obviously. The rate of fat consumption was high. The testis was fusiform shape, light red or yellow, from the front of swim-bladder to cloacal chamber. The ovary was digitation juxtaposed shape, and was wrapped up by fat. The pigment and fat was in the middle and lateral part of the ovary, and the blood vessels distributed on it. The sex of gonad was identified easily at the fourth stage. The gonad was getting close to physiological maturity. A little fat remained in the testis, and the testis was pink because of the bulk of blood vessels. There were some spermatozoa on the face of testis. Testicular duct expanded containing a small quantity of spermatozoa. The volume of ovary with no fat was large. There were a plenty of egg cells which were coated by diaphanous membrane, and the diameter of the ovum macroaxis was between 2.5-4mm. In the fifth stage the abdomen of fish was inflated and soft, and the gonad was matured. Pressing the abdomen lightly, the ivory sperm or pitchy egg would flow from the cloacal opening. After mature, the更多还原