野生鲻鱼和养殖鲻鱼消化系统的组织学观察

野生与养殖鲻鱼(Mugil cephalus)的消化系统在形态和组织结构上存在一定差异.(1)形态方面:食道粗而短,胃呈球形,包括贲门部、盲囊部、胃体部和幽门部4个区域,胃与肠相接处有2个指状幽门盲囊,肠道在腹腔内盘旋5圈.肝脏黄褐色,右叶较左叶大,未发现独立的胰脏.养殖鲻鱼消化道周围包裹更多脂肪,胃较小但胃腔更大,肠...

On histology of digestive system of wild and cultivated prey mullet Mugil cephalus

Results showed that there were some differences between wild and cultivated grey mullet in the shape and histology of digestive system.(1)In terms of morphology : oesophagus was crude and short;the spherical stomach was divided into four portions: cardia,gastric caeca,fundic stomach and pyloric part.There were two finger-shape pyloric caeca,intestine was circled 5 laps in the abdominal cavity.Brown liver,right lobe was larger than the left lobe,single pancreas was not found.For cultivated mullet,the digestive tract was wrapped by more fat,the stomach smaller but stomach cavity bigger.Intestinal tract was longer than that of wild mullet.Meanwhile the average intestinal coefficient of Mugil cephalus was 2.909 for the wild and 3.080 for the cultivated mullet;(2)Histological studies have shown that:there were two regions in the oesophagus,including cranial with pavement epitheliums and caudal with simple columnar epitheliums,and muscularis mucosa was thicker;in wild mullet,the surface of esophageal mucosa was covered with keratinocytes,and longitudinal muscle was thicker.Stomach had a single-layered columnar epithelium under which in the mucosa of cardiac and fundic portion well-developed gastric glands and gastric pits were present.The mucosal folds and small mucosal fold in cultivated mullet was higher than that of the wild mullet.The mucosa of fundic stomach was composed of stratified squamous epithelium with many goblet cells,the muscle of fundic stomach and pyloric part was almost the entire thickness of the stomach,and the wild mullet was thicker.The histological features of pyloric caeca were similar to the cranial intestine's.The intestine epithelium was composed of simple columnar cells with a distinct brush border,in which there were many goblet cells.Meanwhile the distribution trends in the whole intestine was:hindgut>foregut>midgut and cultivated mullet >wild mullet.The mucosal folds of wild mullet was showing irregular branch-like,and non-branching strip to cultured mullet.The liver lobule was not clear but its hepatic cell cord was obvious.The pancraes were distributed in the surrounding mesentery around the stomach,gut and bile duct.