Carapace surface smooth and about 1 ½ times as wide as long in males, less in females; medially convex with central longitudinal crest; anterior margins undulated and expanded almost as far forward as rostrum which broadens distally. Eyestalk cone-shaped with small cornea. Antennal scale leaf-like. Chelipeds unequal in size, smooth, and with short setae on inner margins of fingers. Walking legs much compressed with sharp dorsal margins; dactyl short with ventral movable spines and sharp, curved claw. Abdomen of female wider than that of male.
SizeCarapace: male 65 x 90 mm, female 68 x 87 mm.
ColourCarapace with unusually broad range of colour; small individuals are often white or pale brown, and males of any size may be scarlet. Otherwise combinations of all shades of orange, pink, red-brown, green, grey purple and white occur. One colour may predominate or there may be a mixture with spots, streaks, or a pattern of finely etched, usually symmetrical, lines. Appendages and ventral surfaces mostly white. Chelipeds and walking legs usually have tinges of tan or brown. Eyestalk white; cornea black. Antennal flagellum banded in light and dark brown.