Effects of Different Temperatures and pH on the Protease and Amylase Activities in the Digestive Tract of Anguilla rostrata

[Objective] The study aimed to know the digestive physiological characteristics of Anguilla rostrata,and provide scientific basis for its feed formulation and reasonably feeding.[Method] With healthy juvenile A.rostrata weighted about 30 g as tested material,the tissues from stomach,intestine and hepatopancreas were made for homogenate and centrifuge.With the obtained supernatants as tested enzyme liquid,the changes of protease and amylase activities in 3 kinds of digestive tissues under the reaction temperature of 20～60 ℃ and pH of 1.0～12.0 were determined resp.The effects of different temperatures and pH on the protease and amylase activities in stomach,intestine and hepatopancreas of A.rostrata and the activities and change law of these digestive enzymes in different digestive organs.[Result] The optimum temperatures and pH were 55,55,50 ℃ and 2.0,7.5,7.5 resp.in turn for protease,the optimum temperatures were all 40 ℃ and the optimum pH were 4.0,7.0,7.0 resp.for amylase in stomach,intestine and hepatopancreas of A.rostrata.Under the mode of reaction temperature,the order of protease activity in different peptic was stomach intestine hepatopancreas,the order of amylase activity was hepatopancreas intestine stomach.Under model of pH,the order of protease activity was intestine stomach hepatopancreas,and that of amylase was hepatopancreas intestine stomach.[Conclusion] The protease activity of A.rostrata were higher in stomach and intestine,while the amylase activity were lower.The A/P value of A.rostrata were all less than 1,which indicated that it was carnivorous or partial to be carnivorous.