Rostrum triangular, reaching near end of first antennular article. Large chela 2.4 times as long as broad. Superior margin of chela proximal to dactyl with transverse shallow depression, extending on inner palm as shallow triangular depression, on outer palm as quadrangular depression. Inferior margin of chela deeply notched opposite superior groove, notch U-shaped. Small chela sexually dimorphic, male chela balaeniceps. Ischium of third pereopod bearing movable spine.
body greenish-brown, faint pale longitudinal stripes on abdomen, chela brownish, fingers of larger chela orange apically violet.
common size :
TL 5.5 cm.
Orbital hoods unarmed, autochthonous species with large grooved chela have spinose orbital hoods. Inner lip of notch on upper surface of chela not overhanging, movable finger of smaller chela in male with fringe of setae.
BIOLOGY / ECOLOGY
Euryhaline. Ovigerous females in July, August.
sand, mud flat, rock and rubble; intertidal to 18 m, once record in 36 m.