Gobies and Blennies are small fish well suited for the reef tank and each perform a duty in keeping the tank clean. They are bottom dwellers and many gobies will sift through the bottom substrate for food keeping it stirred, while blennies will perch on live rocks eating microalgae. They are somewhat territorial and only one of each species should be kept except for larger tanks. Neon Gobies are cleaners which will service tank mates and help control some diseases and parasites. In a well established reef aquarium these fish will find their own food and do not have to be fed.