Salmoneus cristatus (Coutière, 1897) is one of the first described species in the alpheid genus Jousseaumea Coutière, 1897, a name later invalidated and replaced by Salmoneus Holthuis, 1955. The species was described based on material from Djibouti and was initially characterised by the presence of a pronounced, posteriorly extending carina on the mid-dorsal line of the carapace, a shoulder-like elevation of the orbital hoods, and a red-banded colour pattern. Relying mainly on morphological features, various authors reported S. cristatus from several localities in the Indo-West Pacific, from the Red Sea to southern China and Australia. However, recently collected material attributable to S. cristatus on morphological grounds allowed for the combination of morphological characters, molecular data and colour patterns, demonstrating the existence of at least four species under the name of S. cristatus, including three species that are morphologically similar to, but phylogenetically distant from S. cristatus s. str. Therefore, S. cristatus is redescribed herein based on recent material from Saudi Arabia and Iran, as well as older material from Israel and Madagascar, with designation of a neotype from the Red Sea coast of Saudi Arabia. Three new species, viz. S. paracristatus sp. nov., S. franseni sp. nov., and S. alius sp. nov., are described based on recent material from Papua New Guinea for the former two species, and New Caledonia, Papua New Guinea and the Solomon Islands for the latter species. However, at least two of these new species seem to have wider distributions in the Indo-West Pacific.
Keywords: Alpheid shrimps; Indo-West Pacific; Marine biodiversity; New species; Phylogeny; Salmoneus.