In a large skillet, melt the butter over medium heat and saute shrimp until pink. Add crabmeat and cook one more minute or until heated through. Set aside.
Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain.
Transfer the shrimp and crabmeat to a large mixing bowl and let cool to room temperature. Stir in pasta, celery, bell pepper and green onion. Add mozzarella cheese, slivered toasted almonds, mayonnaise and lemon juice. Season with parsley, and old bay seasoning. Toss to mix thoroughly.