细鳞鲑早期发育过程中的消化系统发生  

Organogenesis of the digestive system in Brachymystax lenok during early development

作　　者：徐革锋[1,2] 刘洋[1] 李永发[1] 牟振波[1] 

机构地区：[1]中国水产科学研究院黑龙江水产研究所,黑龙江哈尔滨150070 [2]东北农业大学动学科技学院,黑龙江哈尔滨150030

出　　处：《中国水产科学》2013年第4期733-742,共10页Journal of Fishery Sciences of China

基　　金："十二五"农村领域国家科技计划(2012BAD26B05);国家科技支撑计划(2012BAD25B10);中央级公益性科研院所基本科研业务费专项(HSY201312)

摘　　要：应用连续切片技术和显微观察法,对胚胎至幼鱼期的细鳞鲑(Brachymystax lenok)消化系统(口咽腔、胃、幽门盲囊以及肠道等组织)早期发生进行了系统研究。研究表明,在实验水温为12.0～16.2℃时,细鳞鲑胚胎期消化系统原基发生与分化的过程为,在卵受精后125～165 h,胚胎进入原肠期发育,随着原肠作用的进行,脊索开始分化;卵受精后201 h,消化系统原基细胞团在脊索下方出现,为单层的扁平细胞;卵受精后480 h,消化系统原基位于脊索和卵黄囊之间,呈直管状;卵受精后552 h,管状消化系统内层细胞大量增殖,外层由两层细胞构成。细鳞鲑胚后消化系统的发育过程为,初孵仔鱼即具有富含油球的大卵黄囊,消化系统呈简单的盲管状,肛门尚未与外界连通;2～7 DAH,仔鱼消化系统分化加快;7 DAH后,仔鱼已初步分化出口咽腔、食道、胃、肠以及肝;10 DAH,仔鱼消化器官已基本分化完毕,肛门已向外界连通;14 DAH,仔鱼从内源性营养向外源性营养的过渡基本完成,卵黄囊和油球吸收完毕;19 DAH,稚鱼胃固有膜内出现胃腺;49 DAH,幼鱼幽门盲囊分化完毕,肝和胰脏功能完善;64 DAH,幼鱼口咽腔和胃的组织结构与成鱼基本相同,前后肠组织结构相似;105 DAH,幼鱼幽门盲囊指状分支已具有28～36个。细鳞鲑仔鱼的最佳人工开口驯化时间应该在10～14 DAH,可通过不断投喂适口饲料的方式来强化仔鱼的主动摄食行为。本研究旨在为深入了解细鳞鲑仔鱼的消化生理、摄食转变及开口驯化时机提供基础资料。Brachymystax lenok is an economically important, cold, freshwater species in China. The species is cultured because of its taste and high protein value. Knowledge of the ontogeny of the alimentary canal and accessory glands is essential for understanding the nutritional physiology of B. lenok larvae and juveniles. We described the development of the digestive tract in B. lenok larvae reared under culture conditions based on histological observation. The larvae were held in one of three 0.3 m^3 circular tanks （12-16.2℃）for 185 d and fed an artificial diet. Based on the structural changes in the digestive system, we identified three distinct stages during embryonic development： （1） 0-201 h post-fertilization; （2） 202-480 h post-fertilization, and （3） 481-552 h post-fertilization. During the first stage, the embryo initiated the intestinal phase of development, the original base cells of the digestive tract were localized below the chordoma, in a single layer of flat cells. During the second stage, the original base cells of the digestive tract began to differentiate into a straight tube. During the third stage, the inner layer cells of the digestive tube proliferate, and the outer layer forms as two layers of cells. At the end of the embryonic period, the hatched larvae have an oil-rich yolk sac, a simple digestive system that resembles a blind tube, and lack of external connection in the anus. Between 2-7 days after hatch （DAH）, the digestive system begins to rapidly differentiate but larvae remain entirely dependent on endogenous nutrition from the yolk sac. At 7 DAH, the digestive tract was fully differentiated into the buccopharynx, esophagus, non-glandular and glandular stomach, and anterior and posterior intestine. By 14 DAH, larvae were transitioning from being dependent on en- dogenous nutrition to being exotrophic. The yolk sac was completely absorbed. At 49 DAH, the pyloric caeca was completely differentiated, and the liver and pancreas were functional. Between 64-105 DAH, the orop

关 键 词：细鳞鲑 消化系统 幼鱼 胚胎 器官发生 组织学 形态学 

分 类 号：S963[农业科学—水产养殖]