Watchman Goby (Cryptocentrus  pavoninoides) - Watchman Goby, commonly referred to as the Sulphur Goby  
It should be housed in a 30 gallon or larger aquarium with plenty of loose coral rubble. It requires ample swimming room and a sand bottom for burrowing. Rarely will it become aggressive towards other fish, but it is territorial, and will fight with its own kind unless they are a mated pair.
The Watchman Goby feeds mostly on prey suspended in the water column but will pick food off the substrate. The diet should include mysis shrimp, brine shrimp, and table shrimp. It should be fed at least three times per day.
The blue spotted watchman goby is a species of goby native to the western central Pacific Ocean where it occurs in coastal waters at depths of from 1 to 15 meters forming small colonies on the sea floor. It grows to a length of 15 centimeters