The fiddler crab has a rectangular gray-white carapace that is 1-3 cm wide with an H-shaped groove in the center. The chelae of the male are distinctly different in size. The claw is mostly yellow with granules all over the outer side of the major claw. The pollex has a vertical groove on the outer margin and protruding triangular teeth at the base. Sexual dimorphism is apparent, as the claws of the female are small and symmetrical. These crabs are active when the tide ebbs and are often away from their burrows foraging. Courting and mating occurs on the surface, where males wave their claw vertically in an effort to attract females.
This fiddler crab can be seen on mudflats with small puddles along the south shore of Gaomei Wetlands.
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