Designation of a new genus Bathymenes for the deep-sea pontoniine shrimps of the ‘Periclimenes alcocki species group’ (Decapoda, Caridea, Palaemonidae), with a checklist of the species assigned to the genus

A new genus of the deep-sea pontoniine shrimps, Bathymenes gen. nov., is established for the ‘ Periclimenes alcocki species group’ of the genus Periclimenes Costa, 1844. The new genus is distinguished from other genera of the Pontoniinae by a combination of characters: the posteriormost dorsal rostral tooth remote from other teeth, situated in the epigastric position, cornea usually reduced, the propodus of second pereiopods covered with fine granules, the dactylus of the major second chela being generally flanged, the ambulatory pereiopods with the dactyli being biunguiculate and telson with more than two pairs of dorsolateral spines. The genus is mainly distributed in the tropical to warm-temperate Indo-West Pacific waters at depths greater than 200 m. Fifteen species previously recognized as belonging to the ‘P. a lcocki species group’ are now placed in Bathymenes gen. nov. A key for their identification and a checklist of congeneric species are provided.