Three new species of pagurid hermit crabs (Decapoda: Anomura: Paguroidea) from the Northern Mariana Islands, Micronesia.

We describe three new species of hermit crab of the pagurid genera, Catapagurus A. Milne-Edwards, 1880, Nematopagurus A. Milne-Edwards Bouvier, 1892 and Pagurixus Melin, 1939, on the basis of material collected during the scientific cruise to the Northern Mariana Islands conducted by the U.S. National Oceanographic and Atmospheric Administration (NOAA) in 2015. Catapagurus tenuilamina n. sp., referred to the C. ensifer Henderson, 1893 species group, appears close to C. granulatus Edmondson, 1951, but differs from the latter in the more slender ultimate article of the antennular peduncle, more slender dactyli of pereopods 2 and 3, and the possession of two dorsal subdistal spines in the meri of the pereopods. Nematopagurus marianicus n. sp. resembles N. gardineri Alcock, 1905 and N. lewinsohni Trkay, 1986, but is distinguished from the latter two by the characteristic dense setation on the upper part of the left cheliped carpus and by the elongate dactyli of pereopods 2 and 3 that lack a row of bristle-like setae on the dorsal margins. Pagurixus eminens n. sp. is referred to the P. boninensis Melin, 1939 species group and appears closest to P. annulus Komai Poupin, 2013, but is differentiated from the latter in the shape and ornamentation of the right coxa of pereopod 5 in the male as well as details of the colour pattern on the chelipeds and ambulatory legs. Partial sequences of the mitochondrial 16S rRNA gene from the three new species were sequenced and deposited in the GenBank database for future genetic and phylogenetic study.