Put paprika, sage, cumin, garlic powder, sugar, salt, cayenne and onion powder in a 1-gallon food-storage bag. Close bag and shake until well blended. Put 1 fillet in bag at a time and shake until lightly coated. Coat large nonstick skillet with cooking spray. Add oil and heat over medium-low heat until hot. Add catfish fillets, skinned side up, and cook 4 to 5 minutes until lightly blackened. Carefully turn with spatula. Cook 4 to 5 minutes longer, or until fish feels firm and is opaque at the thickest part. Serve with lemon slices.