The term "fiddler crab" refers to about 100 species and subspecies of crabs from the genus Uca. They’re found along beaches and brackish (a mixture of saltwater and freshwater) waterways around the world. Male and female fiddler crabs are easily distinguished by looking at their claws. The females have small claws while the males have one distinctive large claw. This large claw, held in such a way that it resembles a fiddle (violin), is how fiddler crabs got their name. Fiddler crabs are fun to watch and fairly easy to keep as pets, with few health concerns and docile personalities. Their housing takes up minimal space, and there are many commercial foods available to provide them with a balanced diet.
Fiddler Crab Behavior and Temperament
Unlike land hermit crabs, fiddler crabs spend a lot of their time in water. In the wild, they retreat to muddy burrows as the ocean tide goes out. In addition to digging burrows, picking up food, and defending themselves, fiddler crabs also use their claws to communicate. They will raise and lower their claws like a wave, which alerts other crabs to their presence.
Fiddler crabs should be handled as little as possible, as this can cause them undue stress. Plus, they might pinch you with their claws if you frighten them. Instead, simply enjoy watching them as they move about their tank. And expect to spend just a few hours per week on feedings and keeping the tank clean.
Housing the Fiddler Crab
Provide at least a 10-gallon aquarium if you have one to four fiddler crabs. Add 3 to 5 more gallons of tank space per each additional crab. Overcrowding is a major source of stress for crabs, and it can lead to health problems and aggression. Make sure the tank has a secure lid with ventilation (such as a mesh screen), as fiddler crabs can climb out of their tank when given the chance.