I've bought many of dourada catfish, about 8, over years. I am sure some of them or most /all of them had been fed live before coming to me. I never offered anything live, only humble catfish pellets and thawed fish cut to appropriate size. Usually within the first week they started taking new feeds. In a couple of weeks they would firmly take to the new feeds... if comfortable, which can be hard with these fish. They are skittish and bolt full speed from perceived threats until hitting a wall and eventually can kill themselves.