1. Preheat oven to 425.
2. Place fish in an 11X7 inch baking dish coated with cooking spray.
3. Combine lime juice, mayonnaise, onion powder, and pepper in a small bowl and spread over fish.
4. Sprinkle with breadcrumbs; drizzle with butter.
5. Bake for 20 minutes or until fish flakes easily with a fork; sprinkle with parsley.