Place the shrimp in a small bowl. Cover with ½ cup lime juice and ½ cup lemon juice. Cover and refrigerate until the shrimp have turned pink, about 2 hours.
In a separate bowl combine the remaining ingredients (except the radicchio and the endive), allow to marinate for at least one hour.
Just prior to serving, drain the shrimp, add to the mango bowl and toss to combine.
Scoop a few tablespoons of the ceviche into the leaves of the endive and the radicchio, serve chilled
Notes
For a lower heat level, reduce Sriracha to 1/4 or 1/2 tsp.