The Mudflat Fiddler Crab

A male mudflat fiddler crab (Uca rapax) waves its huge claw to impress females and threaten competitors. Only the males have the large claw. When the tide is high, fiddler crabs retreat to their burrows. More about the animals and plants living in mangrove ecosystems can be found in the Mangroves section.

Credit: 

Steven Paton/Smithsonian Tropical Research Institute