He is a Japanese pistol shrimp- The Japanese Pistol Shrimp may also be called the Red Pistol Shrimp, and originates from Sri Lanka. Their body is bright red in coloration, and is marked with several white spots. The base of the tail and the claws are also banded in white. These beneficial shrimp will constantly move gravel making them excellent sand stirrers in the reef aquarium, as well as scavenging any uneaten food.
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 very small shrimp. They may form a symbiotic relationship with a shrimp goby if they are compatible.