Kumepagurus Komai & Osawa, 2012

Komai, Tomoyuki, Rahayu, Dwi Listyo & Fujita, Yoshihisa, 2021, Hermit crabs of the family Paguridae (Crustacea: Decapoda: Anomura) from Christmas and Cocos (Keeling) Islands, Indian Ocean Territory of Australia, with descriptions of three new species and reappraisal of the genus Kumepagurus Komai & Osawa, 2012, Raffles Bulletin of Zoology 69, pp. 378-402 : 384-385

Genus Kumepagurus Komai & Osawa, 2012

Type species. Kumepagurus cavernicolus Komai & Osawa, 2012 .

Emended diagnosis. Gills biserial, 13 pairs (2 arthrobranchs above bases of maxilliped 3 and pereopods 1–4, and pleurobranch on thoracomeres 5–7). Ocular acicles simple. Maxilliped 3 with crista dentata consisting of widely spaced teeth; no accessory tooth. Right cheliped massive, chela operculiform; dactylus articulating obliquely with palm. Left cheliped fixed finger terminating in 2 tiny corneous claws. Pereopods 4 simple, with propodal rasp consisting of single row of corneous scales; no preungual process. Male with medium, coiled, laterally oriented sexual tube on coxa of right pereopod 5; left coxa with short sexual tube, directed posteriorly or posterolaterally, tapering distally to slender, acute tip. Male with unpaired left pleopods 3–5. Female with paired pleopods 1, modified as gonopods; unpaired left pleopods 2–5; paired gonopores on pereopods 3 coxae. Pleon dextrally twisted. Pleomere 6 tergite not strongly calcified. Telson with terminal margins oblique; anterior lobe posterolateral margins each with conspicuous tuft of setae.

Composition. Kumepagurus covernicolus (type species of the genus) and K. noelensis , new species.

Remarks. Kumepagurus was originally established for K. cavernicolus Komai & Osawa, 2012 , described from a unique male holotype from a marine cave on Kume Island, Ryukyu Islands. Subsequently, Komai (2020) described a new species, K. kaikata , on the basis of material from sublittoral water on Kaikata Seamount, Ogasawara Islands , Japan, although the generic assignment was considered provisional because of the difference in the gill number (13 pairs in K. cavernicolus versus 11 pairs in K. kaikata ). The assignment was based on the lack of an accessory tooth on the maxilliped 3 ischium, the operculiform right chela, the presence of two distal corneous claws on the left chela fixed finger, the simple pereopods 4, and the development and structure of the male sexual tubes on both coxae of pereopods 5 ( Komai, 2020); all shared by the type species of the genus, although the gill number has been one of the critical characters to diagnose paguroid genera (cf. McLaughlin, 2003). The discovery of the present new species, for which both male and female specimens are available for study, confirms that Kumepagurus kaikata Komai, 2020 , is indeed generically distinct from the other two species of Kumepagurus . In addition to the difference in gill number, Kumepagurus kaikata differs from Kumepagurus noelensis , new species, in the absence of paired pleopods 1 in the female, which are present in the new species. A new genus, Vounopagurus , is established for Kumepagurus kaikata (see below).