Found some info for you, hope this helps:
The Pistol Shrimp may also be called Symbiosis Shrimp and Snapping Shrimp. It is found in a variety of colors and sizes. Pistol Shrimp are not easily sexed, but the males of many species are thought to have a larger pincher. The sound it makes comes from an appendage on the pincher which moves when the pincher is opened or closed and water is ejected. The Pistol Shrimp can be easily confused with Mantis Shrimp if judged by sound only. Unlike the Mantis Shrimp, it is not harmful and will not pose any threat in the tank, with the possible exception of smaller shrimp.
The name Symbiotic Shrimp comes from the equally beneficial relationship the Pistol Shrimp has with gobies (e.g.;Amblyeleotris or Stenogobius). The goby, with better eyesight, warns the shrimp of predators. The shrimp share its food with the goby. Depending upon the species, Pistol Shrimp may also have symbiotic relationships with sponges, corals, or anemones (e.g.; Bartholomea annulata).
It is beneficial to the tank as it churns the sand. It thrives in environments with sand, rock caves, and dim light. If in pairs, one will often stand guard at the burrow while the other is inside. The Pistol Shrimp are intolerant of copper or high nitrate levels, but need a correct level of iodine in the water to promote proper molting.
Pistol Shrimp will accept freeze-dried and frozen foods and bottom feeder tablets. The Pistol Shrimp are intolerant of copper or high nitrate levels, but need a correct level of iodine in the water to promote proper molting.