斑点鳟(Oncorhynchus mykiss)稚鱼消化道组织学观察

The histological observation of Oncorhynchus mykiss digestive tract

利用石蜡切片技术观察斑点鳟稚鱼（Oncorhynchus mykis）消化道组织。结果表明，斑点鳟稚鱼的消化道分为口咽腔、食管、胃肠管3个部分，食管、胃、幽门盲囊、肠管均由黏膜层、黏膜下层、肌层和浆膜层4层组成。食管、胃部结缔组织中有大量腺体，胃体幽门部长有44～46条不等幽门盲囊，幽门盲囊中皱褶相互挤压，几乎充满整个腔体；肠管自胃贲门起至肛门段，肠壁逐渐变薄，褶皱数量逐渐减少，后肠处观察有大量黏液分泌细胞。因此，斑点鳟消化道组织结构具有肉食性鱼类消化道的典型特征，可进行以动物蛋白为主的配合饲料日常多次投喂饲养。本研究结果可为斑点鳟稚鱼配合饲料的开发提供参考。

The digestive tract of juvenile Oncorhynchus mykiss was observed by paraffin tissue section. The results showed that its digestive tract consisted of oral - pharyngeal cavity, esophagus, and gastrointestinal tract. The tissue of esophagus, stomach, pyloric caeca, and intestine consisted of 4 layers, which were mucous menbrane, submucosa, muscularis, and serous membrane. There were a large number of glands observed in the connective tissue of esopha- gus and stomach. There were 44 - 46 pyloric caeca in the pyloru. The folds in pyloric caeca extruded one by one and almost covered the whole cavity. From gastric cardia to anus, the intestinal wall was gradually thinning, and the number of folds were also gradually decreased. A great number of mucus secretion cells were observed in hindgut. Therefore, the gastrointestinal histoXogy of Oncorhynchus mykiss demonstrated the typical characteristics of carnivorous fishes. Oncorhynchus mykiss can be fed with the formula feed based mainly on animal protein for many times in the routine. The results provided references for the development of formula feed to juvenile Oncorhynchus mykiss.