Common name: Emerald Crab

Mithraculus is a genus of small crabs often referred to as Emerald Crabs in the reefkeeping community. These crabs are popular for their vibrant green coloration and their appetite for algae, including bubble algae which can be problematic in reef tanks. They are generally peaceful and can be a beneficial addition to a clean-up crew in a reef aquarium. They are known for their ability to navigate around corals without causing harm, making them a safe choice for reef enthusiasts. It's important to provide them with ample hiding spaces and ensure they have enough algae to graze on, as they can turn to corals for food if underfed.