A revision of the genus Scylla de Haan, 1833 (Crustacea: Decapoda: Brachyura: portunidae)

Abstract

There has been considerable confusion regarding the taxonomy of species in the genus Scylla, commonly known as mud or mangrove crabs. To resolve this confusion we collected material from the Red Sea (the original type locality of Scylla serrata), and from many other locations throughout the Indo-Pacific. Two independent genetic methods, allozyme electrophoresis and sequencing of two mitochondrial DNA genes, cytochrome oxidase I and I 6s RNA, were employed in an attempt to discriminate species. The genetic data show that there are at least four distinct Scylla species. Using this knowledge their morphology was critically examined, and morphometric data analysed, to determine useful characters for field separation. Nomenclatural problems have been addressed with appropriate neotype and lectotype designations. The species recognised are: S. serrata (Forskal, I 775), S. olivacea (Herbst, 1796), S. tranquebarica (Fabricius, 1798), and S. paramamosain Estampador, 1949.