1. In a large bowl, combine cornmeal, flour, salt, pepper, paprika, garlic powder, and onion powder.
2. Pour buttermilk into another bowl. Dip each catfish fillet in buttermilk, then dredge in the cornmeal mixture, ensuring an even coat.
3. Heat vegetable oil in a frying pan over medium-high heat. Fry catfish fillets for about 3-4 minutes on each side, or until golden brown and cooked through.
4. Remove fillets from the pan and drain on paper towels. Serve hot.