多鳞四指马(鲅)幼鱼消化道形态学和组织学的初步观察

摘要

对多鳞四指马鲅(Eleutheronema rhadinum)幼鱼消化道的形态解剖和组织显微结构进行了初步研究.结果表明:多鳞四指马(鲅)幼鱼的消化道从前到后依次是口咽腔、食道、胃、幽门盲囊和肠.口裂宽大,上下颌、犁骨和腭骨上均有绒毛状臼齿.食道的粘膜上皮为复层扁平上皮,上皮内含有粘液细胞.胃Y型,分为贲门部、盲囊部及幽门部,胃的粘膜上皮是单层柱状细胞,其间无杯状细胞,贲门部和盲囊部均有胃腺,而幽门部未发现.肠由前肠、中肠和后肠构成,Z字形,肠道系数为0.508,肠道的粘膜上皮是单层柱状细胞,上皮细胞游离面的微绒毛密集排列形成纹状缘,粘膜上皮中含有大量杯状细胞,粘膜层中并未发现肠腺的存在.由前肠到后肠粘膜皱褶的厚度和宽度呈现低-高-低的变化趋势,而肌层厚度则是高-低-高的变化趋势.幽门盲囊菜花状,其组织学结构类似于肠道结构,但粘膜上皮中无杯状细胞.%The morphology and histology of the digestive tract in young Eleulheronenw rhadinum were observed by optical micro-scopes. The digestive tract was composed of orol-pharyngeal cavity, esophagus, stomach, pcyloric caeca and intestines. The orol-pharyngeal cavity was large, and there were villiform molars rnon the jaw teeth, palate teeth and vomerine teeth. The mucosa of esophagus was covered with stratified squamous epithelium with many mucous cells. The Y-shaped stomach consisited of cardia, blind sac and pylorus. The stomach had a single-layered columnar epithelium, in the lamina propria of cardia and blind sac, enormous stomach glands were present, while no goblet cells was detected in the whole stomach. Intestines were Z-shaped, including foregut, midgut and hindgut, and the average intestinal coefficient was about 0.583. The intestine epithelium was composed of simple columnar cells with a distinct microvillus brush border in which there were many goblet cells, while intestinal gland was not detected in intestines. The low-high-low tendency was found in the mucosal thickness and width from front to back, whereas the muscularis was in the contrary condition. Pcyloric caeca was like cauliflower, the histological characters were similar to that of the intestines, but no goblet cells was found in the epithelium.