Effect of Temperature on the Activities of Digestive Enzymes in Catfish(Silurus asotus Linnaeus) in the Jialing River

An experiment was conducted to study the effect of temperature on the activities of digestive enzymes in stomach,intestine and hepatopancreas of Silurus asotus by means of enzymology analysis.The results showed that within the range of the designed temperature the activities of all digestive enzymes in S.asotus increased at first and then decreased.The optimal temperature was 40 ℃,44 ℃ and 36 ℃,respectively,for protease and 44 ℃,40 ℃and 40 ℃,respectively,for amylase in the stomach,the intestine and the hepatopancreas of the fish.The optimum temperature for lipase in all the organs studied was 36 ℃.Under the optimum temperature,the activity of protease in different organs was in the order of anterior intestinehepatopancreasstomachmiddle intestineposterior intestine,and the activity of both amylase and lipase was in the order of hepatopancreasstomachanterior intestinemiddle intestineposterior intestine.Significant differences(p0.05) existed among different digestive organs at the same temperature,indicating that the activities of digestive enzymes in S.asotus are organ-specific.