塔里木裂腹鱼消化系统形态学与组织学研究

利用传统石蜡切片、HE染色等方法对塔里木裂腹鱼(Schizothorax biddulphi)消化系统形态学和组织学特征进行研究。结果显示，塔里木裂腹鱼消化系统由消化管和消化腺组成，消化管包括口咽腔、食道和肠(前肠、中肠、后肠和直肠)。口咽腔内具有发达的咽齿。无胃，肠与食道紧接，前肠膨大。消化道由腔面向外依次为黏膜层、黏膜下层、肌层和浆膜层，但口咽腔只有黏膜层、黏膜下层和肌层，未发现有浆膜层。消化道4层中，黏膜层差异最大：口咽腔黏膜层为复层扁平上皮，其间分布有味蕾和大量黏液细胞；食道粗而短，黏膜层为复层扁平上皮，黏膜褶两侧分布大量黏液细胞，且固有膜血管丰富；肠道上皮细胞为单层柱状上皮，上皮间分布有杯状细胞，其数量由前向后逐渐增加，而黏膜褶高度逐渐降低。消化腺由肝脏和胰脏组成，肝脏的肝小叶不明显，但明显可见肝血窦及中央静脉分布，肝门管区不典型。胰脏仅在肠系膜中出现，而未在其他组织中发现，胰小叶间中央静脉明显，中央静脉中可见大量椭圆形有核的红细胞。本研究对塔里木裂腹鱼消化系统形态学和组织学特征与其食性的关系进行了探讨，旨在丰富塔里木裂腹鱼的生物学研究内容，可为其食性分析及饵料开发提供理论依据。

Morphology and Histology Studies of the Digestive System of Schizothorax biddulphi

This study aimed to investigate the morphological and histological features of the digestive system of Schizothorax biddulphi using conventional HE-stained paraffin sections. The digestive system of S. biddulphi consisted of a digestive tract and a digestive gland. The digestive tract comprised the oropharynx, esophagus, and intestine (anterior intestine, middle intestine, posterior intestine, and rectum). A pharyngeal tooth had developed in the oropharynx, but no stomach was present; the intestine adjoined the esophagus and the anterior intestine was inflated. The general structure of the digestive tract consisted of the mucosa, submucosa, muscular layer and serous membrane; however, the oropharyngeal cavity only had the mucosa and muscular layer. The mucosal layer showed the greatest difference, mainly in the following aspects. First, the tunica mucosa of the oropharynx was made of a stratified squamous epithelium with taste buds and numerous mucous cells. Second, the esophagus was thick and short, and the mucosa consisted of a stratified squamous epithelium. Third, there was a large number of blood vessels in the lamina propria. Last, the intestinal epithelial cells were single columnar epithelial cells, and the number of goblet cells increased gradually from the anterior intestine to the rectum, while the mucosal fold height gradually decreased. The digestive gland of S. biddulphi is composed of a liver and pancreas. The hepatic lobule of the liver was not obvious, but the distribution of hepatic sinuses and central veins was regular, however, the portal area of the liver was not typical. The pancreas was an independent structure, separated from the liver, and not found in any tissue other than the mesentery. The veins were more obvious in the pancreatic lobule, and there were numerous nucleated red blood cells in the vascular system. The relationship between morphological and histological features of the digestive system and feeding behavior of S. biddulphi was discussed, in order to enrich the biological research of S. biddulphi and to provide a theoretical basis for the analysis of its trophic behavior and development of its bait.