Effects of Different Types of Culture Condition and Diets on the Digestive Enzymes of Bleeker(Erythroculter ilishaeformis)

Four groups of bleeker(Erythroculter ilishaeformis) which are wild group(WG) harvested from Taihu lake,artificial group(AG) cultured with compound feed, with trash fish(TG) and no extra adding feed(NG) in ponds respectively,were collected.The experiment was conducted to investigate the effect of different type culture condition and diets on the three kinds of digestive enzymes such as protease,amylase and lipase.The results showed that the activities of protease,amylase and lipase in intestine were much higher than that in hepatopancreas(P0.05).The activity of protease was in descent ranged as: NGAGTGWG.The insufficient food at intervals may result in the lower activity of protease in WG.The activities of protease in foregut and hindgut of NG were 3.1—1.8 and 3.2—1.8 times as that in the same sector comparing with the other three groups.The activities of protease in AG were in ascent ranged as along with the different gut sector,contrary to the activities of protease in TG.It may result from the texture and moisture content of different feeds because the artificial feed is more firm than that of trash fish.In hepatopancreas,the activities of protease was significantly lower in TG than that in AG(P0.05).The activities of amylase in hepatopancreas were declined as follow as NGTGWGAG.In whole gut,except in hindgut,the activity of amylase was highest in TG and lowest in WG.The activity of lipase was in descent ranged as: AGWGTGNG,but there was no significant difference among the four groups except for the activity in hindgut.The lipase activity of hindgut in TG was significantly lower than that in AG and NG.It has shown that different types of culture condition and diets had less influence on lipase activity comparing with that of protease in bleeker.