【作者】 周海燕；

【导师】 刘筠；

【作者基本信息】 湖南师范大学 ， 动物学， 2004， 硕士

【摘要】 大鲵(Andrias davidianus)俗称娃娃鱼，属两栖类，有尾目，隐鳃鲵科，是国家二级保护动物和世界上最大的珍稀两栖动物。自20世纪70年代起，许多学者围绕大鲵的人工养殖、性腺发育和人工繁殖等方面进行了大量的调查和研究工作，丰富了大鲵的生物学资料。为了进一步研究大鲵繁殖生物学规律以及探讨大鲵人工受精率、人工孵化率低的原因，我们对人工养殖条件下的大鲵性腺发育规律、人工繁殖技术等方面进行了研究和探讨，现将结果报道如下： 一、大鲵性腺发育规律的研究 1．大鲵精巢发育规律：运用组织学切片技术和电镜技术对大鲵精巢进行了观察，大鲵精巢表面被覆致密的结缔组织，精巢内部由精细管和精细管之间的疏松结缔组织组成，精细管由生精细胞和支持细胞两类细胞组成。研究表明：大鲵由精原细胞发育为成熟精子的过程与鱼类、哺乳动物一样经历了5个发育阶段，即精原细胞→初级精母细胞→次级精母细胞→精子细胞→精子。大鲵精子由头部、中片和尾部三部分组成：头部呈棒状，细胞核前端呈细丝状，棒状细胞核内染色质高度浓缩；头部后端凹陷，称为中片，内有线粒体和中心粒结构；精子尾部细长，主要由轴丝和附属纤维组成，轴丝的外面具有波动膜。在精细管腔内成熟精子头并头、尾并尾成束排列。2.大统卵巢发育规律:运用石蜡切片技术，根据卵巢发育过程中卵细胞的形态和生理特征以及卵攀本身的组织学成分〔’〕，将卵巢划分为6(I一班)个时期。由于受到材料来源的限制，未能观察到I期卵巢的形态特征。11期卵巢以11时相卵母细胞为主，含有少量的亦原细胞。在冬季，己达性成熟的大蜕的卵巢属于11期卵巢。11时相卵母细 一~胞核质比大，滤泡细胞为单层，细胞质强嗜碱性，有许多核仁位子细胞核的边缘，核内可观察到灯刷染色体。111期卵巢:呈扁平囊状，卵巢一内卵粒肉眼可见，以m时相卵母细胞为主，也有11时相卵母细胞和少量的卵原细胞，在春季，己达性成熟的大蜕的卵巢属于111期卵巢。 ~111时相卵母细胞体积增大，滤泡细胞为双层，卵母细胞和滤抱细胞之间有一层较薄的放射膜，细胞质变为弱嗜碱性的疏松网状结构，核周围的细胞质更为疏松，卵母细胞皮质中有时可见少量的卵黄沉积。W期卵粱:是乡归桑棒积增长最快的时期，卵粱外观皇黄色，命粱占据腹腔后部较大空何，卵集腔内充满卵粒，经组织学切片观察，一w期卵巢内含有w时相、m时相和11时相的卵母细胞及少童的如原细胞，在夏季，己达性成熟的大貌的卵集属于W斯卵巢。w时相卵母细胞属初级卵母细胞进入到大生长期，卵母细胞内卵黄逐渐积累直至充满整个卵母细胞质，细胞体积迅速增长，在放射膜上观察到呈涌斗状画陷的受精孔，几受精孔内嵌合着一个精孔细胞。V期卵巢:卵巢内可观察到v时相卵细胞，以及w、llLn时相的卵母细胞和少量的几卵原细施。v时柑卵细咆处于第二次成熟分裂中期。在人工养殖条件下，一几W时相晚期卵母细胞经人工催产可发育一为生理成熟的卵子(V时相卵母细胞)，卵子为游离状态，具有受精能力。VI期卵巢:即产后卵巢，卵巢呈萎缩状，卵巢内可见许多皱缩的空滤泡腔和产后黄体。二、大蜕的人工繁殖 采用人工催产、人工受精的方法，开展了大织人工繁殖工作。结合对大蜕性腺发育规律的研究，初步确定人工养殖条件下大蜕的最佳繁殖季节为6、7月份，在繁殖季节选择体质健壮的亲貌进行人工催产，人工催产采用人工注射外源激素:鱼用绒毛膜促性腺激素(HCG)和促黄体生成素释放激素类似物(LRH一A)来促使大鱿排卵和产精，注射时采用两种激素混合一次性注射，注射剂量根据大蜕体重而定。人工受精采用干法受精:待雌性大鱿在池中开始产出卵带后，将大蜕放于木板桌面上，让其腹部朝上，人工将大鱿卵带拉出，放于光滑无水的盆中后，将人工挤出的且经过显微镜镜检的大鱿精液覆盖于卵带上，略加稀释液，缓慢转动盆子，使精卵充分结合，静置10分钟后加入池水，待30分钟后分装于孵化器具中进行孵化。在20.5℃士0.5℃条件下，大织受精卵经过27一29天发育过程，孵化为幼苗。更多还原

【Abstract】 Andrias davidianus is the biggest amphibian in the world. It’s protected as the secondary-order animal, in China. Many scholars have made survey and studies on the gonad development, farming and artificial reproductive of it and enriched the biological resources of it. For the deep study on the reproductive biological regularity of it and also exploration to the reason why the artificial insemination rate was low, we made a lot of studies and exploration on the hand of gonad development and artificial reproduction of it. The results were summarized as follows: 1 The gonad development of Andrias davidianus 1. The test is development of Andrias davidianusThe test is was covered with serous membrane in the surface. The essensce of testis consisted of seminiferous and loose connective tissue between seminiferous and the seminiferous epithelium in seminiferous consisted of spermatogenic cells and supporting cells. The spermatogenic cells developing from spermatogenous cells to mature spermatozoon included five phases and it was similar with other vertebrate. When the spermatozoon was not mature, they juxtaposed with tales on one side and heads on the other side. And it was different with othervertebrate. The spermatozoon consisted of a head, a middle piece and a tail. In the head there was a stick-like nucleus with highly condensed chromatin in it. There was a fossa in the end of the head and centrioles and mitochondria were located in the fossa. The tail of the spermatozoon was thin and long and with an undulating membrane. 2. The ovary development of Andrias davidianusOn the condition of artificial farming, it was distinctive that the season regularity of the development of ovary. The ovary development was divided into six phases. In the nuclear of II phase ovocyte, there were many lamp brush chromosome, and from III phase ovocyte there were some yolk, the yolk were farctus in IV phase ovary. 2 The artificial reproduction of Andrias davidianusWith the method of artificial ripening, we carried out artificial reproduction of Andrias davidianus. We found that the reproductive season of it were June, July and August and with the water temperature of 20. 5 + 0. 5C, Andrias davidianus embryogenesis needed 27 to 29 days.更多还原