Family: Portunidae
Commom name: Box crab
Synonym: Portunus lucifer, Goniosoma luciferum, Charybdis lucifera Cancer philargius, Calappa dristata

Main morphological features:
Carapace bare, but with microscopic granules and transverse ridges; front with 6 teeth, middle four subequal in size, outermost teeth narrower and sharper; anterolateral margin with 6 teeth, first to fifth gradually increasing in size,; the last the smallest, spiniform. Chelipeds asymmetrical, merus with 3 spines on the anterior margin;, carpus with a stout spine at the inner angle and 3 obtuse spines on the outer surface,; manus with 5 short spines on the dorsal surface. M; merus of the forth ambulatory legs with a spine at subtermination.

Colour:
Carapace purple, abdomen white; posterior portion of carapace marked with 4 pale yellow elliptical-shaped spots; tips of spines of chelipeds spines and anterolateral teeth reddish brown; tips of cheliped fingers black.

Specimen size:
Carapace length of the male 66.0 mm, breadth 95.0 mm.

Distribution:
China (Taiwan), Japan, Thailand, Malaysia, Indonesia, Sri Lanka and India.

Habitat:
Habitat: Inhabits on muddy-sandy or reef-associated bottoms.