Beautiful specimen of spiny crab Charybdis from Indonesia. Completely natural. Found in the forest inland of the island of Java. Dating back to the Miocene period. Charybdis is a genus of crabs belonging to the family Portunidae, and like other members of this group, they are characterized by the flattening of the fifth pair of legs which are used for swimming. This adaptation, combined with their powerful claws, allows this genus of decapods to be strong and agile predators.