Abstract:

Organization structure characteristics of digestive system and feeding are closely related, for basic research in different appetites freshwater fish feed, four freshwater fishes, like Xenocypris davidi Bleeker, Hypophthalmichthys molitrix, Erythroculter ilishaeformis Bleeker and Monopterus albus, are studied. The histology of the digestive system in the four species fishes were studied by optical microscopes and H.E dyeability. The organizational structure characteristics have been compared, include ratio of intestine gut length to body length, density of goblet cell, mucosal muscularis aggregate thickness, mucosal ruffle quantity and length, liver and pancreas, and so on. In this study, the relationship among the feeding, environment, evolution and the morphological characteristics of digestive system histology with the four species were discussed. The results show that ratio of intestine gut length to body length is longest in Xenocypris davidi Bleeker and Hypophth- almichthys molitrix. Goblet cells are distributes in buccopharyngeal cavity epithelial cells of Erythroculter ilishaeformis Bleeker, Hypophthalmichthys molitrix and Monopterus albus, but not in buccopharyngeal cavity epithelial cells of Xenocypris davidi Bleeker. Buccopharyngeal cavity Muscle layer is more thicker in Xenocypris davidi Bleeker than in other three fish, and the gills is the densest in Hypophthalmichthys molitrix. The ability of conveying food of esophageal and Intestinal digestion absorption ability becoming more and more little from Xenocypris davidi Bleeker, Hypophthalmichthys molitrix, Erythroculter ilishaeformis Bleeker to Monopterus albus. Digestive gland evolution is with the evolution of species direction as from Xenocypris davidi Bleeker, Hypophthalmichthys molitrix, Erythroculter ilishaeformis Bleeker to Monopterus albus.Then concluded that histologic features are adapt to predatory of fish and living environment, we should fully considered histologic features and living environment in feed formula design.