The Convict Blenny is also commonly referred to as the Engineer Blenny. It is in a separate family from the gobies and blennies. Its markings change throughout its life. Consistently, the colors involved are dark blue to black on white. As a juvenile, the markings are horizontal, running the length of the body. With age, they become vertical bands.It should be kept in a 30 gallon or larger aquarium with a sand covered bottom where it may make burrows. It needs peaceful tank mates and plenty of hiding places. Small groups or pairs tend to do better in an aquarium, but need to be introduced simultaneously to the tank.