Fiddler crabs are small, colorful crabs that are popular in the aquarium hobby. They are named for the distinctive oversized claw that the male of the species uses to attract mates and ward off predators. Fiddler crabs are native to estuaries and marshes along the coasts of the Americas, Africa, and Asia, and they are often found in brackish or slightly salty water. In the aquarium hobby, they are usually kept in freshwater aquariums, and they can be a fun and interesting addition to a community tank. Fiddler crabs are social creatures that prefer to live in groups, and they require an aquarium with a mix of land and water areas, as well as a source of food and shelter.