Place the shredded carrots, chopped celery and red onion in a large bowl. Cook your pasta shells till Al dente and rinse. Add to the vegetables. Drain the can tiny shrimp. Add the shrimp to the pasta and vegetables. Add in the Mayonnaise, salt, pepper and lemon juice. Gently stir till all ingredients are mixed well. Place in covered bowl and chill for 2 hours. When ready to serve sprinkle with paprika.