I know this might be a little late, but I have a cube w/ a Peacock Mantis Shrimp. Also inside I have a Damsel fish and a Blemmie ( I dont know if thats spelled right). Though I think each shrimp is different, they all live very well together and are even allowed in the Matis Shrimp's den. One impotant thing if you want other fish in the tank w/ the mantis is to keep him well fed so that he doesn't go after the others. We are going to get a clown fish and anenome next and see how they do. Our tank is set up w/ lots of different corals also and though he will rearrange sometimes, most of the time he stays close to the ground and doesnt mess with things up on the rocks. Hope that helps if you havent already gone w/ the seahorses, we love our mantis he has personality and is as interested in you as you are in him.