1. It is quite difficult to identify the species of Coenobita purpureus and Coenobita rugosus for some small individuals or white colour adult individuals, but for most individuals it was possible to determine by means of the existence of a black band on the lower surfaces of the eyestalks, outer surface of propodus of 3rd walking leg and male coxae of 5th legs.
2. Generally, Coenobita rugosus with bushy and more obvious granules (on outer surface of left cheliped) than Coenobita purpureus.