Activities of main digestive enzymes of Exopalaemon modestus in Taihu Lake at different growth stages

Activities of main digestive enzymes of Exopalaemon modestus at different growth stages were studied.The results showed that the growth of E.modestus could be divided into three stages based on the digestive enzymes activity.The first stage was when the body weight below 0.1 g and the protease activity continued rising with the increasing size of shrimp.The second stage was when the body weight was 0.1～0.3 g and the protease activity declined to varying degrees.The third stage was when the body weight was over 0.4 g and the protease activity reduced further.Additionally,the activities of lipase,amylase and cellulose were very weak.There was significant difference among the digestive enzyme activities of three different digestive organs of hepatopancreas,stomach and intestine in adult shrimps.The order of protease activity from strong to weak was stomach hepatopancreasintestine,and the order of amylase activity was stomachintestine,hepatopancreas.