Effects of starvation on digestive organs and activities of protease and amylase of largemouth bass (Micropterus salmoides)

An experiment was conducted to study the effects of starvation and refeeding on digestive organs and the activities of protease and amylase in largemouth bass (Micropterus salmoides). The course of starvation lasted for 30 days. From day 3 the liver weight/body weight (LW/BW) began decrease (P < 0.05), and maintained a constant after 20 days of starvation (P > 0.05). The pyloric caeca weight/body weight (PW/BW) grew up first, and then went down. The stomach weight/body weight (SW/BW) kept growing through the starvation period (P < 0.05). The intestine weight/body weight (IW/BW) maintained stably for the first 10 days (P > 0.05).The intestine length/body length (IL/BL) kept growing (P < 0.05). The activity of protease in stomach was increasing for the first 3 days, and decreasing after day 10. The activity of protease in pyloric caeca was decreasing from day 10. The activity of protease in intestine decreased during the entire starvation period.The activities of amylase in liver, stomach and pyloric caeca all went down after starvation (P < 0.05). The activity of amylase in intestine kept at lower level after day 10. When refeeding was applied, the activities of protease and amylase increased, and returned to normal level after 10 days of refeeding.