虹鳟与鲤鱼消化系统形态和组织学研究

Study on morphology and histology of the digestive system in Oncorhynchus mykiss and Cyprinus carpio

探究虹鳟和鲤鱼消化系统结构异同及其与食性的关系。采用解剖和组织染色对虹鳟和鲤鱼消化系统进行了形态和组织学研究。结果显示,鲤鱼胃部微有隆起,呈I型,肠长而细;虹鳟胃部膨大,呈U型,肠形复杂。虹鳟的肝脏和胰脏是分开的,肝分两叶,胰脏主要分布在围绕幽门盲囊的脂肪组织表面上;鲤鱼肝胰脏外观上混杂在一起,肝小叶不明显,胰腺多分布于肝脏浅表部位。虹鳟和鲤鱼胃、肠肌层排列均是内层为环肌,外层为纵肌,不同的是虹鳟肌层环肌较纵肌发达得多。虹鳟的胃里有大量胃腺,胃是其重要的消化场所,而鲤鱼的胃里没有胃腺,鲤鱼的胃不具备化学消化功能,其真正消化吸收的场所是肠。虹鳟消化系统在形态和组织学方面具有典型肉食性鱼类的特点。

The study was designed to investigate the difference in digestive system and its relationship with feeding habits of rainbow trout(Oncorhynchus mykiss)and carp(Cyprinus carpio).Morphological and histological studies on the digestive system of rainbow trout and carp were conducted by anatomical and histological staining techniques.Results showed that the stomach of carp was I-shape and the intestine was long and thin.The stomach of rainbow trout was U-shape and the intestine was more complex.The liver of rainbow trout was morphologically separate from the pancreas and divided into two lobes,and pancreas was scattered on the surface of the adipose tissue surrounding the pyloric caeca.The hepatopancreas of carp was morphologically mixed together,hepatic lobule was not obvious,and pancreatic tissue was distributed mainly in the superficial layer of liver.The arrangement of the muscle layers in the stomach and intestine of rainbow trout and carp was the same that the inner layer was circular muscle layer and the outer layer was longitudinal muscle layer,however,the circular muscle layer of rainbow trout was much more developed than the longitudinal muscle layer.There were a large number of gastric glands in the stomach of rainbow trout,and the stomach was important as a site of digestion.There was no gastric gland in the stomach of carp,therefore the stomach of carp had no chemical digestion function,and the intestine was the site of digestion and absorption for carp.The results suggest that the digestive system of rainbow trout shows typical characteristics of carnivorous fish.