In a large saucepan, over medium heat, add the oil. When the oil is hot, stir in the onions, celery, and carrots. Season the vegetables with salt, cayenne, and bay leaves. Saute for 6 minutes, or until the vegetables are soft and tender. Stir in the clam juice and tomatoes and bring up to a boil. Add the potatoes and corn. Simmer for 15 minutes, or until the potatoes are fork tender. Season the seafood with salt and cayenne. Add the seafood and simmer the soup for 5 minutes. Stir in the parsley and ladle the soup into serving bowls.