Place the shrimp, red onion, jalapeno, cucumber, tomatoes, and cilantro in a large bowl.
In a smaller bowl, mix the lime, lemon and orange juices. Pour over the shrimp and vegetable mixture. Season with salt and pepper to taste and mix gently to combine.
Cover and refrigerate for 15 minutes. Add the chopped avocado and gently mix to combine. Serve.
Notes
You can purchase any size shrimp as it will be cut into smaller pieces.
You can marinate the shrimp and vegetables and refrigerate for up to 8 hours. Add the avocado before serving.