Vounopagurus, Komai & Rahayu & Fujita, 2021

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 : 390-391

Vounopagurus , new genus

Type species. Kumepagurus kaikata Komai, 2020 , by monotypy.

Diagnosis. Gills biserial, 11 pairs (2 arthrobranchs above bases of maxilliped 3 and pereopods 1–4, and pleurobranch on thoracomere 7). Ocular acicles simple. Maxilliped 3 with crista dentata consisting of moderately 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 without pleopods 1; 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.

Remarks. Kumepagurus kaikata , originally described on the basis of material containing both male and female, was provisionally assigned to Kumepagurus because of 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 similar development and structure of the sexual tubes, in spite of the different gill formula (11 pairs versus 13 pairs). Kumepagurus noelensis , new species, agrees well with the type species of Kumepagurus , K. cavernicolus , in every diagnostic aspect, including the gill number (13 pairs). There is little doubt that the two species are congeneric. It is remarkable that female specimens of K. noelensis , new species, have paired pleopods 1 modified as gonopods. In contrast, in female specimens of K. kaikata , there are no paired pleopods 1. The differences in the gill formula (11 pairs in K. kaikata versus 13 pairs in K. cavernicolus and K. noelensis , new species) and the development of female pleopods 1 (absent in K. kaikata versus present in K. noelensis , new species) fully warrant the establishment of a new genus for K. kaikata following the current criteria in the generic classification of the Paguridae (cf. McLaughlin, 2003). Here, K. kaikata is reassigned to a new genus, Vounopagurus , as Vounopagurus kaikata , new combination.

Etymology. The name is a combination of the Greek ‘vouno’ (= mountain), referring to the seamount ( Kaikata Seamount ) where the type species was found, and combined with Pagurus . The gender is masculine, as in Pagurus .