Thaw fish, if frozen. Rinse fish; pat dry with paper towels.
Cook pasta according to package directions. Drain, reserving 1/4 cup of the cooking water. Set pasta and water aside. Meanwhile, sprinkle fish with salt and pepper. In an extra-large skillet heat 1 Tbsp. of the oil over medium-high heat. Add fish. Cook about 6 minutes or until fish flakes easily. Remove fish from skillet.
Add the remaining 1 Tbsp. oil to skillet. Add onion and fennel. Cook and stir 5 minutes or until tender. Stir in garlic, capers, and Italian seasoning; cook and stir 1 minute more. Stir in undrained tomatoes, tomato sauce, and the reserved pasta water. Bring to boiling. Boil gently, uncovered, 8 minutes, stirring occasionally. Remove from heat. Stir in the pasta and fish, stirring to break up fish slightly. Sprinkle with parsley.