A new species of the hermit crab genus Pagurus (Decapoda: Anomura: Paguridae) from Pakistan

A new species of the hermit crab genus Pagurus Fabricius, 1775, P. nisari, is described from shallow waters of Pakistan, northern Arabian Sea. It is most closely related to P. decimbranchiae Komai & Osawa, 2001, a species considered to be endemic to Japan. Both species are characterized by the possession of a single rudimentary arthrobranch above the base of the third maxilliped, rather than the typical pair of arthrobranchs typical for the genus Pagurus. The strongly bi-spined interocular lobe and the absence of spines on the ventrolateral and ventromesial margins of the merus of the left cheliped distinguish the new species from R decimbranchiae, although colouration in life is very similar. The new species is placed in the P anachoretus group, as was P. decimbranchiae.