A new species of the alpheid shrimp genus Salmoneus is described and illustrated from Aqaba, the Red Sea. Salmoneus chadwickae, sp. n., is the fifth member of the S. cristatus species-group, it is distinguishable from all congeners by a strongly hooked, right-angled tip of the fixed finger on the major chela.
The new species is compared with known species from the Red Sea, and with other species of the S. cristatus species-group from other Indo-West Pacific regions, and confirmed also with the combined analysis of mitochondrial and nuclear gene sequences (16S and H3, respectively). A 19th century sample of Salmoneus spp. donated by H.
CoutiSre to the Mus,um National d'Histoire Naturelle, Paris, was examined; it revealed a mix of several species that are reported and illustrated here. New records of S. auroculatus from the Philippines, S. aff. cristatus from Papua New Guinea (PNG), S. gracilipes from PNG, and of S. tricristatus from Taiwan, are provided, and a possible occurrence of S. aff. gracilipes and S. aff. seticheles in the Red Sea is discussed.
Five species of the Indo-West Pacific S. cristatus species-group have been analysed using morphological and molecular comparisons. An identification key to the species of the S. cristatus species-group is provided.