Morgan'S Hermit Crab

This hermit crab has a shield 1.15 to 1.4 times as long as it is broad. The rostral lobe is triangular and the lateral projections very small and blunt. The eye-stalks have inflated bases and are nearly as long as the shield. The left cheliped (claw) has four to six robust calcified teeth on its cutting edge and the dactyl has two to four teeth on its cutting edge. The right cheliped is somewhat smaller with fewer teeth. The surfaces of both are dotted with small tubercles and low protuberances. The third pair of pereopods (walking limbs) have a brush of setae (bristles) near the claw while the other pereopods have scattered setae.

Calcinus morgani is found in the tropical and subtropical Indo-Pacific region, its range extending from Madagascar to western, northern and eastern Australia, the Philippines, Indonesia and other western Pacific island groups. It is typically found in the intertidal zone of coral reefs and on rocky shores exposed to strong wave action. This is in contrast to C. gaimardii which prefers sheltered inlets and is found subtidally.