Abstract: Thymallus is a kind of cold water fishes which is rare and endangered now.In this study,the activities of ACP,AKP and CAT related to immunity response were measured in the livers,kidneys and muscles of the wild and farmed populations.The results showed that AKP activities exhibited a tendency among the three tissues in both two populations;with the highest level in kidneys while the lowest in muscles.ACP activities were highest in kidneys while lowest in livers,and CAT activities were highest in livers while lowest in muscles.Meanwhile,ACP activities detected in kidneys and muscles in wild populations were significantly higher than those in farmed population,with a contrast situation in livers.In addition,activities of CAT and AKP in different tissues changed with the same tendency,which was identified to be higher in livers and kidneys of farmed populations while in muscles of wild populations.This study aimed to understand the changeable tendency of the immunity related enzyme activities in wild and farmed Thymallus populations,and might offer the important guidance to the artificial reproduction and culture of Thymallus.

Key words: Thymallus, wild population, farmed population, Alkaline phosphatase, Acid phosphatase, Catalase