The number of different types of catfish is amazingly large, with over 30 different species found in the United States alone. Catfish are native to all the continents, but are found mostly countries bordering the Atlantic and Indian oceans, and generally are not found in the Pacific regions. South America accounts for the overwhelming majority of different catfish species.To the average American, the most important of the different types of catfish, is the one that is pan fried, Cajun-style. This is typically one of the species of channel catfish, at times caught in the wild, at other times coming from catfish farms. The largest catfish in the United States is the Mississippi catfish, which often weighs well over 100 pounds, and is considered to be an excellent food fish.