Macrobrachium ngankeeae, a new species of freshwater shrimp (Crustacea: Decapoda: Palaemonidae) from Papua Barat Province, Indonesia

A new freshwater prawn, Macrobrachium ngankeeae n. sp., is described from two rivers in the Kaimana Regency on the southern coast of Papua Barat Province, Indonesia. The new species belongs to the Macrobrachium placidulum species- group, but it can be easily distinguished from the other members of this group by having fewer postorbital teeth and the epigastric tooth placed more anteriorly with a relatively shorter epigastric length, i.e. 0.23–0.27 of carapace length (vs 0.24–0.55 in the other species members). Other distinguishing morphological characters and a molecular analysis of this new species are discussed. A key to the species of the M. placidulum species-group is also provided.