THE EFFECT OF PERIODIC STARVATION ON FEEDING,GROWTH AND DIGESTIVE ENZYME ACTIVITY OF MIICHTHYS MIIUY JUVENILE

Food shortage is often a stress in natural environment to many fish species,causing growth retardation or even death. However,response to the stress differs in species. After the food become available again,they would re-gain growth,which is called compensatory growth. In this study,juvenile of Miichthys miiuy was tested for the effect of periodic starvation on feeding,growth,and digestive enzyme activity. At 22±2℃,the juveniles were divided into four groups(S0,S3,S6,and S12) ,which were starved for 0,3,6,12 days and then fed for 0,3,6,12 days respectively. All individuals were tested in starvation-feeding in 72 days. The results showed that the daily performance of weight growth is significantly different among groups in feed efficiency,feed rate,and specific growth rate. The juvenile M. miiuy is able to develop in partially compensatory manner. Moreover,changes in three digestive enzymes are different too. In early starvation,protease,lipase,and amylase decreased in stomach,intestine,and liver. As the starvation continues,all three enzymes increased at different rates. After re-feed the fish,contents of lipase and amylase rebounded. As the feeding time passed,changes in the content of digestive enzyme in digestive organs were different among five groups.