短盖巨脂鲤(Piaractusbrachypomum)消化系统组织形态学研究

Histomorphology of Digestive System of the White Achama (Piaractus brachypomum)

短盖巨脂鲤 (Piaractusbrachypomum)消化系统由口咽腔、食道、胃、前肠、中肠、后肠、肛门、肝脏和胰脏等构成。口咽腔内具有发达的颌齿和数量多的绒毛状咽齿。口咽腔粘膜褶蜂窝状 ,粘膜上皮为复层扁平上皮。食道粗短 ,表面具发达的纵行褶。食道粘膜的复层上皮具有丰富的粘液细胞。胃呈“V”形 ,粘膜表层为单层柱状上皮 ,贲门部上皮下有一层发达的胃腺组织。肠道较短 ,幽门盲囊发达。肠上皮都为单层柱状上皮 ,其间分布着较多的粘液细胞。中、后肠吸收细胞顶端有少量蛋白质吞噬颗粒。肝脏较大 ,分叶。胰脏为弥散性 ,在肠系膜周围、幽门盲囊之间、肝脏内部都有分布。短盖巨脂鲤是杂食性鱼类 ,但其消化系统有着肉食性鱼类消化系统特点。

The digestive system of the white achama consists of oral-pharyneal cavity,oesophagus,stomach,fore-gut,mid-gut,hind-gut,anus,liver and pancreas.There are strong teeth in the mouth and villi-formed teeth in pharynx.The epithelium of oral-pharyngeal cavity is multi-layered.The oesophagus with longitudinal fold on the inner wall is short and thick. The epithelium of oesophagus is also multi-layered,and with plenty of mucous cells in it. The V-shaped stomach has a single-layered columnar epithelium. In the cardiac portion,gastric glands are well developed under the epithelium. The gut is short, and its epthelium consist of columnar cells,among which mucous cells are distributed. Many protein granules are found in the upper part of the absorbtive cells of the mid-gut and hind-gut. The liver is big and lobulated. The pancraes distributes among the liver,around the gut and between the pyloric caeces. Although it's a omnivore fish,all these characters indicate the digestive system of the white achama has the character of that of the carnivorous fish.