STUDY ON DISTRIBUTION CHARACTERISTICS OF INTESTINAL MUCOUS CELLS AND DIGESTIVE ENZYME ACTIVITIES IN PARAMISGURNUS DABRYANUS

Distribution of mucous cells and digestive enzyme activities in the intestinal tract of Paramisgurnus dabryanus were analyzed by AB-PAS histochemical staining and enzymatic testing techniques. The results showed that there were four types of P. dabryanus intestinal tract mucous cells (Ⅰ‒Ⅳ). The number of mucous cells decreased from the anterior to posterior intestinal tract. The types of mucous cells in anterior intestinal tract were mainly mixed Ⅲ and Ⅳ types. The mucous cells, however, consisted of mainly Ⅱ and Ⅳ acidic types in the posterior intestine. Trypsin activity was significantly higher than amylase and lipase activities. Digestive enzyme activities in the posterior intestine were lower than that in the anterior and middle intestine. According to distribution characteristics of the intestinal mucous cells and digestive enzyme activities, P. dabryanus appears to be a type of polyphagic fish. Its intestinal tract has digestion and respiratory functions. Digestion and absorption occur in the anterior intestine. In the posterior intestine, the lack of neutral mucus cells and low digestive enzyme activities indicate that its digestive and absorptive abilities are weak. It may be related to its assistive respiratory function.