Scylla serrata (often called mud crab or mangrove crab, although both terms are highly ambiguous, as well as black crab) is an ecologically important species of crab found in the estuaries and mangroves of Africa, Australasia and Asia. In their most common form, the shell colour varies from a deep, mottled green to very dark brown Our Mud Crabs are caught from the vast pristine estuaries around natuna islands.