Redescription of Petrolisthes militaris (Heller, 1862), with description of a new species from the Indo-West Pacific (Decapoda, Porcellanidae)

Petrolisthes militaris (Heller, 1862) is redescribed on the basis of material from the Nationaal Natuurhistorisch Museum - Naturalis, Leiden, and the Museum National d'Histoire Naturelle, Paris. A different morphotype, consistently showing a different distributional and ecological range from that of Petrolisthes militaris , is here described as Petrolisthes holthuisi n. sp. Phylogenetic analyses of a dataset based on DNA sequences of a fragment of the mitochondrial COI gene from individuals representing the two forms support the separation of these into two species. While Petrolisthes militaris has a wide distribution in the Indo-West Pacific including the Red Sea, the new species seems to be restricted to the western side of the Malayan Peninsula through the Malayan Archipelago, eastward to Vanuatu. In addition, Petrolisthes militaris has a broad bathymetric range from the intertidal to 600 m, while Petrolisthes holthuisi n. sp. is limited to shallow water. Keywords: Petrolisthes holthuisi ; Petrolisthes militaris