Dactylus of fifth pereiopod paddle shaped. Frontal margin cut into six lobes. Distant between the external angles of the eye orbits is not much less than the width of the carapace. Basal antennal segment broad with two fused spines. In adults the antennal flagellum is excluded from the orbit of the eye. Anterolateral margin of carapace with five teeth, the fourth the fourth tooth is the smallest. Carpus of cheliped with four spines.
This species is characterised by its smooth green carapace, which often has two large black spots. Like other swimming crabs, they are predators, feeding on fish and other animals.