THE GROWTH AND DIGESTIVE ENZYMES ACTIVITIES OF COMMON CARP (CYPRINUS CARPIO) DURING LARVAL STAGE

In order to explore activities of digestive enzymes fluctuation of common carp (Cyprinus carpio) larvae during growth stage, this study investigated the growth, soluble protein content and the activities of digestive enzymes of laboratory-reared common carp. The results indicated that total length and body weight of larvae at 40 days after hatching (DAH) increased greatly with a 14.81% growth rate. The activities of amylase, lipase, trypsin, chymotrypsin, alkaline phosphatase and aminopeptidase were detected at 1 DAH in common carp. During the development of larvae, soluble protein content of larvae decreased firstly, and then gradually increased. The activity of digestive enzymes in larvae increased before feeding. With the development of digestive systems and change of alimentation mode, activities of digestive enzymes of larvae changed continually from 3 to 25 DAH. After 25 DAH, activities of digestive enzymes of common crap were relatively stable, a sign of completed larval digestive function. In order to improve the ecological restoration effect of artificial fishnest and reduce starvation effect on the survival rate of larvae, organic materials could be used for artificial fishnest according to the digestive enzyme activity of common carp at different developmental stages.