云南盘鳇消化系统解剖学、组织学及消化酶活性研究

采用形态学、组织学及酶学方法对云南盘逗(Discogobio yunnanensis)成体消化系统进行研究。结果表明, 云南盘逗消化系统有以下特征: 口下位, 口腔上皮分布有较多味蕾及杯状细胞, 食道粗大, 含有大量黏液细胞, 无胃, 肠道较长, 盘旋于体腔中, 成鱼盘旋10回, 肠道系数为5.06±0.61, 肠分为前中后三段, 肠腔中密布肠绒毛。消化腺为肝胰脏, 肝脏分为左右两叶, 胰脏弥散分布在肝脏中。消化系统不同部位消化酶活性大小不同, 脂肪酶活性: 肝胰脏>前肠>中肠>后肠, 胰蛋白酶、淀粉酶、碱性磷酸酶活性: 前肠>中肠>肝胰脏>后肠。云南盘逗口下位, 食道粗短, 肠道细长, 肠绒毛丰富, 肠道含较高的胰蛋白酶和淀粉酶活性, 消化系统所具有的这些特征与其以固着藻类为食有关。

ANATOMICAL,HISTOLOGICAL OBSERVATIONS OF DIGESTIVE SYSTEM AND DIGESTIVE ENZYME ACTIVITY INDISCOGOBIO YUNNANENSIS

The present study investigated the structure and function of the digestive system inDiscogobio yunnanensis by morphological, histological and zymologic methods. Results showed that the mouth ofD. yunnanensis was inferior, and the digestive tract was composed of oral cavity, esophagus and gut without an obvious stomach. Many taste buds and goblet cells were distributed in oral epithelia. The esophagus was short and thick with abundant goblet cells in the mucous layer. The intestinal index was 5.06±0.61, and the gut was the largest part, which hovered in the body cavity. According to the morphology, the gut with abundant villi was divided into the cranial, middle and posterior parts. Di-gestive gland was hepatopancreas, and the liver was divided into two parts, with pancreas diffused in. The different di-gestive parts had diverse digestive enzyme activities. The activities of lipase in different digestive parts ranged as fol-lows: hepatopancreas>foregut>midgut>hindgut, while those of trypsase, amylase and alkaline phosphatase were fore-gut>midgut>hepatopancreas>hindgut. These results suggest the adaptation of this fish in feeding fixed algaes.