Genus
Common name: Mithrax Crabs
Scientific name: Cyclocoeloma
Cyclocoeloma is a genus of crabs commonly known as Mithrax or Emerald Crabs in the reefkeeping community. These crabs are popular for their algae-eating habits, helping to control nuisance algae in the aquarium. They are small, with a distinctive green to greenish-brown coloration, and are generally peaceful, making them suitable for most reef tanks. They are also known for their ability to consume bubble algae, a particularly stubborn type of algae that many other clean-up crew members tend to ignore.