Uca uruguayensis Nobil, 1901 Leptuca uruguayensis, commonly known as the Uruguayan fiddler crab or the southwestern Atlantic fiddler crab, is a species of fiddler crab native to temperate and subtropical areas of the southeastern coast of South America.

[2][3] The adult crab's carapace is usually between 10 and 16.5 millimetres (0.39 and 0.65 in) wide.

[4] The major cheliped can remain red or also whiten.

The crab is native to South America where its range includes Brazil, Uruguay, and Argentina.

[1] The species lives on silty sand or sandy silt soils with some organic matter.