Effects of starvation and refeeding on activities of digestive enzymes in Culter alburnus Basilewsky juveniles

The effects of starvation for diferent time and refeeding on the activities of digestive enzymes (protease, amylase and lipase) in three parts of digestive organs (foregut,hindgut and hepatopancreas) of Culter alburnus Basilewsky juveniles were investigated indoor under 20.3-24.8 ℃.After two weeks acclimation,375 juveniles, body weight (4.22±0.29)g,were divided into ?ve groups(A,B,C ,D and E respectively,three replicates, each 25 individuals),which were starved for 0 d(contro1),4 d,8 d,12 d and 16 d,respectively,then all re-fed for 16 d. The results showed that the activities of digestive enzymes were in?uenced markedly by starvation(P0.05). The activities of three kinds of enzymes all decreased sharply during the ?rst 4-8 days of starvation;the lipase activities of ?sh starved for 12 d still decreased and were greatly lower than those starved for 8 d(P0.05),and then the digestive enzymes activities tended to decrease smoothly. Upon refeeding,the protease activities in the three parts rose quickly,reaching peak on the 4th day,of which the protease activities in hepatopancreas(except the ?sh starved for 4 d) were greatly higher than those before starvation,and then fell down to the level before starvation;after refeeding for 4 d,the amylase activities in three parts mostly reached the level that was greatly higher than those before starvation,and then recovered to the normal level after refeeding for 8 d;the lipase activities also rose to a peak after refeeding,and then recovered to the normal level;the longer time the fish starved,the higher the lipase activities rose. The distribution of the activities of digestive enzymes in three parts of digestive organs of C. alburnus juveniles were also discussed in this paper.