Morphology and histology of digestive tract in Oplegnathus fasciatus

Oplegnathus fasciatus,a marine fish, is of commercial value. With the development of marine aquaculture,the potential culture prospect of Oplegnathus fasciatus is becoming more and more optimistic. And thus it is essential to get appropriate feeds for it. So as a theoretical reference, the morphology and histology of the digestive tract in Oplegnathus fasciatus were studied by optical microscopes.The digestive tract in Oplegnathus fasciatus consists of the buccal pharynx cavity with well-developed mandibular teeth, oesophagus, stomach, intestine and rectum. The oesophagus shows two portions,cranial with pavement epitheliums and caudal with simple columnar epitheliums,and there are many goblet cells and mucous secretory cells in the epitheliums of oesophagus.The V-shaped stomach has a single-layered columnar epithelium under which,in the cardiac and fundic portion,well-developed gastric glands are present. The intestine epithelium is composed of simple columnar cells with a distinct microvillus brush border, in which intestinal glands are distributed, while no muscularis mucosa is detected in the rectum. There are many goblet cells in the epithelium of the intestine and rectum. Meanwhile the average intestinal coefficient of Oplegnathus fasciatus was calculated, which came to about 0.78. Four types of goblet cell were also found in the whole digestive tract. In this paper, the microscopic structure of the digestive tract was studied,and it was proved that the histological and anatomical features of its digestive tract were consistent with the omnivorous habits of Oplegnathus fasciatus. It was expected that greater efforts should be made to have a further study on histochemistry of the digestive tract in Oplegnathus fasciatus.