Emerald Crab (Mithraculus sculptus)

Emerald crabs are a small grazing species of crab very useful for helping control algae growth on live rocks and around coral. They will consume many types of algae including Bryopsis and bubble algae. While peaceful in some cases they may become destructive during feeding and damage soft corals, thankfully this is usually only found in some males though in rare cases females may as well. They will also consume some softer species of macro algae so take care when deciding if emerald crabs are right for your reef.