Catfish are bottomfeeders...but do not confuse that with only eating dead food. Flathead catfish (another large species) are generally caught using live bait. Catfish can only afford to be lazy when living in a river enviroment because they can set up shop in a rivers eddy which inherently bring food to them. Fish that live in lakes are much more active. This is partly the reason that many large cats are caught in Texas lakes. There are many contributing factors required for a body of water to sustain trophy or world record fish, some of those include genetic strain of fish, water temperature, forage base, commericial harvest, fishing pressure, size of water.