Scientific name - Mithraculus sculptus Family – Majidae Common name – Mithrax, Emerald Crab Max Size – 2.5 in (5 cm) Care Level – Easy Temperament – Semi-aggressive Foods and feeding – This crab will scavenge debris and eat algae, especially bubble algae. If there isn’t enough growing in the aquarium you may need to provide supplement diet. Supplements - Calcium, Magnesium, Iodine, Trace Elements Aquarium suitability - Reef compatibility – Yes Captive care – The crab will help clear an aquarium of nuisance bubble algae. They are nocturnal and will spend most of the day hiding in the rockwork. They are an opportunistic predator and may eat fish, corals or other inverts if they get large enough or if there isn’t enough food available. The Emerald Crab comes in a variety of different colors, including red. Crabs are extremely sensitive to nitrates and copper and small amounts will kill them.