Species Specifics You’ll likely hear of three major catfish species across the United States: channels, blues, and flatheads. For this topic of our discussion, we’ll stick with channel cats, as they are the most numerous, inhabiting nearly every waterway, lake and swamp in the South and across the country’s midsection into Canada. Bonus: They are great to eat. Blues are big river fish (think Mississippi), and flatheads are an outlandish predator capable of tipping 100 pounds. Both are incredible fish, and numerous outfitters specialize in trophy fishing for each. But, today, we’ll dial in the broader target: channel cats.