Mud Fiddler Crab

• The male waves his giant claw in a rhythmic motion to court females and warn off rivals, a gesture that recalls a fiddler and gives the group its name.
• If it loses the large claw, it regrows a new one on the opposite side, often lighter and less substantial: it serves to threaten, but it fights less well.
• Its burrows aerate the marsh mud and encourage plant growth, which makes it an ecosystem engineer.
• The male has one disproportionately large claw, almost the size of his own body, which he waves rhythmically to attract females and warn off rivals. Hence the name fiddler crab.
• The other claw is tiny and is the only one he uses to feed, so the male takes twice as long as the female to eat.
• It sifts the mud with its mouthparts, keeps the organic matter and leaves pellets of cleaned sediment at the burrow entrance.
• Its burrows aerate the marsh sediment, which benefits the vegetation.

Skeleton type

Invertebrate - articulated calcareous exoskeleton (crustacean)

Habitat and environment

Brackish saltmarsh and intertidal mudflats of the Atlantic coast of North America

Sources consulted: Wikipedia (es): Uca pugnax · ScienceDirect (Hughes 1989) · Science Advances, How colonial animals evolve · Wikipedia, Zooid

The pins mark the parks and dive sites where its presence is documented.