Abstract:

This paper dealt with the histological structure in the digestive system of young Cromileptes altivelis so as to provide morphological basis for understanding its development and growth characteristics and improving the survival rate in seedling production. Paraffin section and HE staining were used conduced to observe the tissue slice in the digestive tract of young fish. Results showed that mucous cells and taste buds were found both in the lips and tongue, goblet cells were not found in lips, but abundant in tongue; The mucosa layer of esophagus, esophagus was short and think, covered with wrinkles and folds with numerous mucous cells and goblet cells, taste buds were not found, muscle layer of esophagus were well developed which was striated muscle; The stomach consisted of cardiac，blind and pylorus. The account of mucosa layer’s folds:
cardiac stomach > blind stomach> pylorus stomach, the average height of mucosa layer’s folds: blind stomach> cardiac stomach> pylorus stomach. Concave-shaped structure was observed in stomach without goblet cells be found, the gastric gland were well developed; he intestine was divided into foregut, midgut and hindgut. The number and average height of mucosa layer’s folds in intestine: foregut > midgut > hindgut, he striated border was obvious in intestine with numerous goblet cells and mucous cells; he results of observation in pyloric caeca were similar with that in intestine. Lobuli hepatis were obvious. The distribution of central vein was irregular. Hepatic sinusoid was abundant. The hepatic cell cords were obvious, hepatic artery and bile duct could be observed. The pancreas was dispersing around the liver. Langerhans' islet was oval cluster, the pancreatic acinuses were abundant, and the pancreatic cells could be observed obviously. In conclusion: histological structure of digestive system in young stage of C. altivelis is typical carnivorous, and associated with function, feeding habit and environment.

Key words: Cromileptes altivelis, young fish, digestive system, histology