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为探究黄河濒危鱼类兰州鲇(Silurus lanzhouensis)消化系统的形态学和组织学结构特点,以鲇(Silurus asotus)为对照,对兰州鲇消化系统形态学和组织学进行了深入研究。结果表明:(1)兰州鲇与鲇的消化道和消化腺形态相似,具有肉食性鱼类的特征。兰州鲇消化道较短,有发达的“U”型胃,胃内皱褶明显,无幽门盲囊,肠道短且粗,可分为前肠、中肠和后肠三部分,前肠粗大,后肠较细。两种鲇属鱼类都有独立致密的肝脏和胰脏。(2)兰州鲇的比肠长显著大于鲇(P<0.05),比胃重、比肝胰脏重显著低于鲇(P<0.05),但二者的比肠重无显著性差异(P>0.05)。(3)兰州鲇胃的皱襞幅度小于鲇,且环肌层比兰州鲇薄。兰州鲇与鲇前肠的肠黏膜均形成了大量皱襞,肠黏膜、褶皱粗大,但鲇的褶皱分支较细密。兰州鲇与鲇的后肠与前肠相比,肠腔变小,褶皱数量明显减少,高度降低。黏膜层分布有杯状细胞和柱状细胞。兰州鲇与鲇的肝脏肝小叶间缺少结缔组织,分界不明显,而兰州鲇肝细胞的密度大于鲇。综上所述,兰州鲇与鲇的消化系统相似,均符合肉食性鱼类消化系统特征,结合消化生理等研究结果,表明兰州鲇的消化能力弱于鲇,这可能是在自然情况下兰州鲇的分布区域及适应性不及鲇的原因之一。
In order to explore the morphological and histological features of the digestive system of Silurus lanzhouensis in the Yellow River, Silurus asotus was used as a control to study the morphology and histology of the digestive system of the Lanzhou fern. The results showed that: (1) The morphology of digestive tract and digestive gland in Lanzhou population was similar to that of 鲇, with the characteristics of carnivorous fish. Lanzhou 鲇 digestive tract shorter, well-developed “U ” type stomach, stomach folds obvious, no pyloric blind capsule, intestinal short and thick, can be divided into three parts, the foregut, midgut and hindgut, before Intestinal thick, hindgut finer. Both species of fish have independently dense liver and pancreas. (2) Compared with gut (P <0.05), gavage of Lanzhou gruel was significantly larger than gavage (P <0.05), and was significantly lower than gavage (P <0.05) > 0.05). (3) Lanzhou stomachache fold less than 鲇, and the ring muscle thinner than Lanzhou. Lanzhou 鲇 and 鲇 intestinal foregut intestinal mucosa have formed a large number of folds, intestinal mucosa, folds coarse, but 鲇 fold branch more closely. Compared with the hindgut and foregut, the intestine became smaller and the number of folds significantly decreased and the height decreased. Mucosal distribution of goblet cells and columnar cells. Lanzhou 鲇 and 鲇 of the liver lobules between the lack of connective tissue, the boundary is not obvious, and Lanzhou 鲇 hepatocytes density greater than 鲇. In conclusion, the digestive system of Lanzhou chinense and chieh are similar to that of carnivorous fish, and the results of digestive physiology and other researches show that the digestibility of Lanzhou chongnakis is weaker than that of Lanzhou chinense, which may be under natural conditions One of the reasons why the distribution area and adaptability are not enough.