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One male and two female specimens of an undescribed species of the heterogeneous hermit crab genus Pagurus Fabricius, 1775, were found during the study of the collections of the Oceanographic Institute of Cádiz, containing specimens from African and European coasts collected during the scientific cruises carried out between in years 2008–2013. The new species is named Pagurus pectinidactylus n. sp., in reference to the presence of a well-developed toothless pectinate masticatory border in the dactylus of the left cheliped, composed by a row of tightly placed bristles forming a brush-like structure. The new species is compared to morphologically similar congeners, especially those that are genetically closest. Molecular phylogenetic analyses support the morphological delimitation, with P. pectinidactylus n. sp. forming a separate clade, more closely related to a group of South African species belonging to the Pagurus anachoretus group.

Raripagurus roseangelae n. gen., n. sp. (Figs 1A–F, 2A–F, 3A, B) Type material. Holotype: female, cephalic shield length 1.8 mm, CURI 17031, sta CURASUB17–33, 12°04.56′N, 68°53.51′W, Deep Reef Observation Project, Curaçao Sea Aquarium, E of downline, Bapor Kibra, Curaçao, 226– 276 m, 3 Nov 2017, colls. L. Weigt, D.L. Felder, B. Brandt, K. Matterson, USNM 1554278. Description. Shield (Figs. 1A, 3A) subtriangular, approximately 1.1 times as broad as long; dorsal surface weakly convex, glabrous, semi-translucent, lacking linea or grooves except for short linea-d; lateral lobe narrow, weakly delimited; anterior margin between rostrum and lateral projections weakly concave; anterolateral margins sloping; posterior margin roundly truncate. Rostrum rounded, reaching slightly beyond lateral projections. Lateral projections, broadly subtriangular, terminating bluntly. Ocular peduncles stout, approximately 0.5 length of shield; dorsal surfaces naked except for short setae dorsodistally; corneas weakly dilated. Ocular acicles subtriangular, each terminating acutely. Antennular peduncles exceeding distal margins of cornea when fully extended by nearly full length of segment 3 (ultimate). Segments naked or with scattered short setae; segment 1 (basal) with blunt ventromesial distal angle, and small spine on lateral face. Antennal peduncles, when fully extended, exceeding distal margins of corneas by approximately one-third of segment 5. Segment 5 slender, approximately 4 times as long as wide, unarmed except for scattered short setae. Segment 4 unarmed except for scattered short setae. Segment 3 with blunt ventrodistal angle. Segment 2 with dorsolateral distal angle produced into spine-like process with few short setae distolaterally; dorsomesial distal angle with small spine. Segment 1 unarmed, hidden by shield in dorsal view. Antennal acicles slender, straight, reaching forward to approximately distal two-thirds of corneas, each terminating in strong spine with tuft of setae distally. Flagellum reaching to tip of extended right cheliped, with few short setae 1 or less flagellar article in length. Mouthparts not dissected. Maxilliped 3 ischium with crista dentata consisting of approximately 14 small subequal teeth, and accessory tooth. Sternite with strong spine on each side of midline. Chelipeds strongly dissimilar in strength and shape, right distinctly larger and stronger than left. Right cheliped (Figs. 1B, C, 3A, B) dorsoventrally flattened, semi-translucent, dorsal and ventral surfaces of ischium to dactyl glabrous except for scattered setae. Chela ovate, approximately 1.7 times as long as broad; dactyl and fixed finger each terminating in inwardly curved blunt calcareous tip overlapping when closed. Dactyl about as long as palm; cutting edge with 3 subtriangular calcareous teeth approximately same size. Fixed finger cutting edge with 3 calcareous teeth increasing in size distally, becoming crenulate near fingertip. Palm slightly broader than long; dorsal surface slightly convex; ventral surface nearly flat; lateral and mesial margins with scattered short setae. Carpus ovate, dorsal surface slightly convex, ventral surface nearly flat; lateral and mesial margins well defined, each with row of short setae; dorsodistal margin unarmed. Merus subtriangular in cross-section and dorsal outline; dorsal margin rounded; dorsodistal margin unarmed; lateroventral and mesioventral margins weakly crenulate distally, setose. Ischium armed dorsally with blunt, setose spine; ventral margin sharply defined. Coxa with few setae on ventromesial distal angle. Left cheliped (Figs. 1D, 3A, B) slender, somewhat dorsoventrally flattened, reaching to approximately midpoint of chela of right cheliped, with surfaces of ischium to dactyl glabrous except for scattered setae; fingers terminating in inwardly curved tips crossed when closed. Dactyl approximately as long as palm; dorsal surface slightly convex; cutting edge with row of minute corneous spinules; lateral margin rounded. Fixed finger with dorsal surface slightly convex; cutting edge minutely crenulate. Palm dorsal surface slightly convex; ventral surface nearly flat; lateral and mesial margins rounded. Carpus approximately as long as merus, dorsal surface slightly convex; ventral surface nearly flat. Merus subtrianguar in cross-section; lateroventral and mesioventral margins weakly crenulate, with few setae. Ischium with small blunt spine dorsally, ventral margin sharply defined. Coxa with few setae on ventromesial distal angle. Pereopods 2 and 3 (Fig. 2A, B) sparsely setose, subequal left from right. Dactyl straight, approximately 0.9 times as long as propodus, with scattered setae dorsally and ventrally, terminating in sharp corneous claw curving ventrally; ventromesial margin with row of 9 distinct corneous spinules. Propodus straight, surfaces smooth, approximately 1.8 times times as long as carpus, unarmed except for few dorsal and ventral setae. Carpus with blunt dorsodistal angle, with scattered setae dorsally. Merus unarmed except for scattered setae dorsally and ventrally. Ischium unarmed. Anterior lobe of sternite XI (of pereopods 3; Fig. 2C) subovate, glabrous, lacking spines. Pereopod 4 (Fig. 2D, E) semichelate, glabrous except for scattered setae. Dactyl nearly straight, terminating in small corneous spinule; lateral face lacking scales; cutting edge with 4 sharp corneous spinules distally. Propodus ovate (lateral view) lacking scales or rasp; with 4 sharp corneous spines on distal margin opposite to cutting edge of dactyl. Carpus unarmed except for scattered setae dorsally. Merus unarmed. Pereopod 5 chelate (Fig. 2F). Dactyl with 2 minute scales dorsally. Propodus with row of 4 scales on dorsodistal margin. Coxae symmetrical. Uropods (Fig. 1E) nearly symmetrical, with few short setae; exopods each with 2 or 3 rows of minute scales anterodorsally. Telson (Fig. 1F) symmetrical, without transverse suture; terminal margin unarmed, weakly divided medially into 2 broadly rounded lobes. Males unknown. Females with paired gonopores; with paired first pleopods (gonopods), and unpaired left pleopods 2–5. Genetic data. The barcode fragment of the cytochrome c oxidase subunit I (CO1-5P) is provided under GenBank (www.ncbi.nlm.nih.gov/genbank) accession number OQ211624, BOLD (Barcode of Life Database) specimen number PAGNS9001-23 (dataset dx.doi.org/10.5883/DS-CRUSTACE). Color (Fig. 3A, B). Overall semi-translucent; eyestalks pale rose pink with transverse ventrolateral slash of deep red near midlength, cornea turquoise with distinct spotting of deep red; chelipeds largely translucent, very pale yellow-orange cast darkest near margins of segments and joints, overall with scattered minute red spots; meri of chelipeds and pereopods 2 and 3 with pale bands of yellow-orange at proximal and distal ends in addition to another centered just beyond midlength; translucent anterior thorax with pale mottling of salmon pink to rose red, shield slightly more opaque and somewhat more yellowish with faint reddish spots and mottling; pleon translucent, faint reddish markings on pleopods and uropods. Etymology. The species name is given to acknowledge and honor Rose Angela Gulledge (Museum Specialist, National Museum of Natural History, Smithsonian Institution), who has assisted the research of both authors in numerous ways during three decades. Habitat. Found living in the rariphotic zone of the deep reefs of Curaçao, Lesser Antilles. Housing or associations unknown. Distribution. Southeastern Caribbean Sea, known so far only from Curaçao, Lesser Antilles. Depth: 226– 276 m. Remarks. The dorsoventrally flattened condition of the segments of the right cheliped, in particular, the carpus and chela, as well as the presence of what appears to be grasping spinules on the propodus and dactyl of pereopod 4, are unique among the Paguridae. Regrettably, the single known specimen of this new species was found loose in the sample without any indication of housing or possible association with another organism. These morphological adaptations are intriguing, and any explanation of their function at present can only be speculative. The armature of the propodus and dactyl of pereopod 4, however, does suggest that this species may grasp onto some housing or perhaps a soft organism while alive in order to protect its pleon or camouflage the body. The virtually symmetrical uropods and telson might suggest a tubular type of housing or association. The semi-transparent cephalothorax and all appendages might represent an adaptation to adopt the color of a possible host or substrate. The only female known of this new species and type specimen, has paired first pleopods (gonopods), a condition that is considered a defining characteristic of the species in the 13 genera of the Pylopagurus - Tomopagurus group of pagurids (Lemaitre & McLaughlin 2003). However, the reduced number of gills consisting of eight phyllobranchs in this new species, does not make it possible to assign it to any of the Pylopagurus - Tomopagurus group of genera, all of which have 11 pairs of gills., Published as part of Lemaitre, Rafael & Felder, Darryl L., 2023, A new genus and species of micro-pagurid hermit crab (Crustacea, Decapoda, Paguridae) from the rariphotic reef zone in Curaçao Lesser Antilles, Caribbean Sea, pp. 374-380 in Zootaxa 5277 (2) on pages 376-379, DOI: 10.11646/zootaxa.5277.2.7, http://zenodo.org/record/7889980, {"references":["Lemaitre, R. & McLaughlin, P. A. (2003) Revision of Pylopagurus and Tomopagurus (Crustacea: Decapoda: Paguridae) with descriptions of new genera and species. Addendum and taxonomic summary. Proceedings of the Biological Society of Washington, 116 (2), 464 - 486."]}

During field investigations of deep-reefs off the coast of Curaçao in the Lesser Antilles, Caribbean Sea, a female specimen was collected of an undescribed micro-pagurid crab with striking dorso-ventral flattening of the right cheliped. It was further characterized by a reduced branchial formula, fourth pereopods with grasping-like spines instead of typically pagurid rasp-like scales, nearly symmetrical uropods and telson, and a minute pair of first pleopods (gonopods). The single specimen was discovered in samples from the rariphotic zone (~130–309 m) obtained using a suction sampler operated from the manned submersible R/V Curasub over cryptic habitats and surfaces populated by communities of sessile macro-organisms. As the specimen does not fit any known pagurid taxon, we regard it to represent a new monotypic genus. We fully describe this new micro-pagurid as Raripagurus roseangelae n. gen., n. sp. and also provide photographs of its live coloration. The CO1 barcode for the holotype in the Barcode of Life Database and GenBank accession number are included as part of the description for any future phylogenetic investigations.

Raripagurus n. gen. Diagnosis. Eight pairs of biserial phyllobranch gills: 1 on maxillipeds 3, 1 on pereopods 1, 1 on pereopods 2, 2 on pereopods 3, and 3 on pereopods 4 (including 1 pleurobranch). Shield broader than long, glabrous; rostrum broadly triangular, distally rounded. Ocular acicles terminating in acute spine. Ischium of maxilliped 3 with accessory tooth. Chelipeds markedly unequal; carpus and propodus of right distinctly flattened dorsoventrally. Sternite of somite XII (thoracomere 6, pereopod 3) with ovate anterior lobe. Pereopod 4 semichelate, lacking propodal rasp; dactyl and propodus modified for grasping with small sharp spines distally, lacking preungual process. Pereopod 5 chelate, with few scales on rasp of dactyl and propodus. Male unknown. Female with paired gonopores; with paired first pleopods (gonopods) and unpaired left pleopod 2–5. Uropods and telson nearly symmetrical; telson lacking transverse sutures, terminal margin weakly subdivided into 2 broadly unarmed rounded lobes. Species and distribution. Monotypic, with R. roseangelae n. gen., n. sp. known thus far from only Curaçao, Lesser Antilles, in the southeastern Caribbean. Etymology. The generic name is derived from the genus name Pagurus, combined with the Latin prefix rarus, which denotes something scarce or rare, in reference to both the rareness of the morphology of the single species in this new genus and the rare, insufficiently explored rariphotic zone where this new species lives. Remarks. The single species of this, for the time being monotypic genus, is distinct among the Paguridae in the flattened morphology of the right cheliped, grasping condition of the propodus and dactyl of pereopod 4, shape of telson, presence of paired first pleopods (gonopods) in the female, and having a reduced branchial formula of eight gills. Furthermore, the surfaces of carapace and thoracic appendages are unusually smooth, semi-transparent, unarmed, having only scattered setae. The flattened right cheliped and armature of the grasping spines on the propodus and dactyl of pereopod 4 is a unique condition among pagurids. However, other generic diagnostic characters are present in species of a few pagurid genera. In the single species of Raripagurus n. gen. the reduced gill formula with only eight pairs of gills is a character shared with species of Decaphyllus de Saint Laurent, 1968, Paguriscus Lemaitre, Felder & Poupin, 2017, Paguruncio Lemaitre, Felder & Poupin, 2017, and Pusillopagurus Lemaitre, Felder & Poupin, 2017. The shape of the telson of the single species of Raripagurus n. gen., lacking a transverse suture and having a posterior margin without spines or teeth and at most obscurely divided, is similar in species of Enallopaguropsis McLaughlin, 1981. Finally, the presence in the single species of Raripagurus n. gen. of paired pleopods (gonopods) in females is a condition shared with all species of the 13 genera of the Pylopapagurus - Tomopagurus group (Lemaitre & McLaughlin 2003). It would appear that none of these characters alone are indicative of close phylogenetic affinity., Published as part of Lemaitre, Rafael & Felder, Darryl L., 2023, A new genus and species of micro-pagurid hermit crab (Crustacea, Decapoda, Paguridae) from the rariphotic reef zone in Curaçao Lesser Antilles, Caribbean Sea, pp. 374-380 in Zootaxa 5277 (2) on page 375, DOI: 10.11646/zootaxa.5277.2.7, http://zenodo.org/record/7889980, {"references":["Saint Laurent, M. de (1968) Revision des genres Catapaguroides et Cestopagurus et description de quatre genres nouveaux. I. Catapaguroides A. Milne Edwards et Bouvier et Decaphyllus nov. gen. (Crustaces Decapodes Paguridae). Bulletin du Museum national d'Histoire naturelle, Series 2, 39 (5), 923 - 954. [dated 1967, published 1968]","Lemaitre, R., Felder, D. L. & Poupin, J. (2017) Discovery of a new micro-pagurid fauna (Crustacea: Decapoda: Paguridae) in the Lesser Antilles, Caribbean Sea. Zoosystema, 39 (2), 151 - 195. https: // doi. org / 10.5252 / z 2017 n 2 a 1","McLaughlin, P. A. (1981) Revision of Pylopagurus and Tomopagurus (Crustacea: Decapoda: Paguridae), with the descriptions of new genera and species: Part I. Ten new genera of the Paguridae and a redescription of Tomopagurus A. Milne Edwards and Bouvier. Bulletin of Marine Science, 31 (1), 1 - 30.","Lemaitre, R. & McLaughlin, P. A. (2003) Revision of Pylopagurus and Tomopagurus (Crustacea: Decapoda: Paguridae) with descriptions of new genera and species. Addendum and taxonomic summary. Proceedings of the Biological Society of Washington, 116 (2), 464 - 486."]}

Genus Pagurus Fabricius, 1775 Type species. Cancer bernhardus Linnaeus, 1758, by monotypy. Species included. For data on extinct forms, reference is made to lists provided by Schweitzer et al. (2010) and to subsequent records by Beschin et al. (2012), De Angeli & Caporiondo (2017) and Polkowsky & Fraaije (2019). Extant species have recently been discussed by Lemaitre & McLaughlin (2021a)., Published as part of Wallaard, Jonathan J. W., Fraaije, René H. B., Van Bakel, Barry W. M., Nance, John R., Lindholm, Adam & Jagt, John W. M., 2023, New hermit crab species (Anomura, Paguroidea) from the upper Miocene St Marys Formation of Maryland (USA), preserved in their host shells, pp. 389-397 in Zootaxa 5227 (3) on page 390, DOI: 10.11646/zootaxa.5227.3.7, http://zenodo.org/record/7518846, {"references":["Fabricius, J. C. (1775) Systema entomologiae: sistens insectorum classes, ordines, genera, species, adiectis synonymis, locis, descriptionibus, observationibus. Officina Libraria Kortii, Flensbergi et Lipsiae, xxx + 832 pp.","Linnaeus, C. (1758) Systema naturae per regna tria naturae, secundumclasses, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Vol. 1. Editio 10. Reformata. Laurentius Salvius, Holmiae, 824 pp.","Schweitzer, C. E., Feldmann, R. M., Garassino, A., Karasawa, H. & Schweigert, G. (2010) Systematic list of fossil decapod crustacean species. Crustaceana Monographs, 10, 1 - 222.","Beschin, C., De Angeli, A., Checchi, A. & Zarantonello, G. (2012) Crostacei del giacimento eocenico di Grola presso Spagnago di Cornedo Vicentino (Vicenza, Italia settentrionale) (Decapoda, Stomatopoda, Isopoda). Museo di Archeologia e Scienze Naturali \" G. Zannato \", Montecchio Maggiore, Vicenza, 101 pp.","De Angeli, A. & Caporiondo, F. (2017) I granchi eremiti (Crustacea, Decapoda, Anomura, Paguroidea) dell'Eocene medio di cava \" Main \" di Arzignano (Vicenza, Italia settentrionale). Studi Trentini di Scienze Naturali, 96, 11 - 32. [http: // www. muse. it / it / Editoria-Muse / Studi-Trentini-Storia-Naturale / Documents / STSN _ 95 - 2016. aspx]","Polkowsky, S. & Fraaije, R. H. B. (2019) A new Oligocene hermit crab (Decapoda, Anomura, Paguroidea) from the erratic ' Sternberger Gestein', northern Germany. Neues Jahrbuch fur Geologie und Palaontologie Abhandlungen, 291 (1), 61 - 63. https: // doi. org / 10.1127 / njgpa / 2019 / 0789","Lemaitre, R. & McLaughlin, P. (2021 a) World Paguroidea & Lomisoidea database. Pagurus J. C. Fabricius, 1775. World Register of Marine Species. Available from: http: // www. marinespecies. org / aphia. php? p = taxdetails & id = 106854 (accessed 15 March 2021)"]}

Pagurus hazenorum n. sp. (Fig. 1) Zoobank: urn:lsid:zoobank.org:act: 9E06A12D-8371-4F45-B75F-60E3032C4847 Diagnosis. Major carpus (right) covered with small, randomly scattered tubercles, increasing in size toward outer margin, there becoming setose. On minor carpus (left), tubercles arranged in rows and slightly increasing in size toward distal end. Both claws densely covered with large granules, decreasing in size toward outer margin. Outer margins of propodus and dactylus covered with blunt teeth, smaller on dactylus. Outer lateral surface of dactylus with longitudinal, medially elevated surface. Walking legs covered with row of teeth, decreasing in size toward distal end. Dactylus of walking leg only covered by blunt teeth and surface with some longitudinal grooves. Type material. The holotype, and sole specimen known to date, is CMM-I-4785. It is preserved inside its gastropod host shell (Buccinofusus parilis Conrad, 1832), which is severely damaged and allows the hermit crab inside to be observed in more detail. The right and left chelipeds are preserved within the gastropod aperture. A relatively complete walking leg, consisting of carpus, propodus and dactylus, is seen posterior of that aperture. A second walking leg, of which only the carpus is preserved, is found anterior of the aperture, while several fragments of other legs are present just behind the chelipeds. The carapace should have been situated here, but this part of the individual has suffered considerable damage and there is no trace of a carapace. Etymology. In honor of Dr Robert M. Hazen, senior staff scientist at the Carnegie Institution for Science, and his wife, Margaret Hazen, writer and historian. Locality and stratigraphy. Driftwood Beach, Calvert County, Maryland, from the upper Miocene (Tortonian) Little Cove Point Member of the St. Marys Formation in a silty lens within Bed E (Ward & Andrews 2008). Kidwell et al. (2015) identified this level as belonging to “SM-C,” assigned to Shattuck zones 22–23 and part of dinocyst zone 8. Description. Chelipeds stout, broad, with propodus of major (right) claw measuring 21 mm by 14 mm; that of minor (left) claw measuring 16 mm by 12 mm. Entire surface of carpus of major claw covered with small, randomly scattered tubercles, increasing in size and setation toward outer margin. Carpus of minor claw with tubercles arranged in rows and slightly increasing in size toward distal end. Both left and right propodi densely covered with large granules, decreasing in size toward outer margin. Outer margin of propodus arcuate; that of dactylus almost straight. Outer margin of both propodus and dactylus covered with blunt teeth, smaller on latter. Outer lateral surface of dactylus covered with longitudinal, medially elevated ridge. Walking legs covered with row of teeth, decreasing in size toward distal end. Dactylus of walking leg with blunt teeth; surface with some longitudinal grooves. Remarks. The new species compares fairly well with the extant Pagurus impressus (Benedict, 1892), from the west coast of Florida (Provenzano 1959), as well as with Diacanthurus rubricatus Henderson, 1888, from the coast of New Zealand and P. bernhardus (Linnaeus, 1758) from the eastern North Atlantic. Discussion. The assignment of the Maryland material to the genus Pagurus is based on several morphological features which P. hazenorum n. sp. has in common with extant congeners, as described below. Although P. hazenorum n. sp. is preserved in situ within its gastropod shell, the carapace appears to be missing, most likely as a result of the damage to the host shell. Overall, the shape of the dactylus is more elongated and bears a closer cover of granules in P. impressus, whereas that of P. hazenorum n. sp. is stout, with blunt teeth along the outer edge and a cover of large granules. Chelipeds of the present-day D. rubricatus bear small spines, in equal density as in P. hazenorum n. sp. Pagurus bernhardus is comparable as well; this has a coarse ornament which, however, is less dense than that of P. hazenorum n. sp. (see Hyžný & Dulai 2021: fig. 35.8). Our comparison of P. hazenorum n. sp. with both extant and extinct species has yielded numerous forms with closely comparable anatomical features. Molecular and genetic research carried out recently on extant representatives of the genus Pagurus has shown that this is in fact a wastebasket taxon, comprising forms with closely comparable morphologies, but widely divergent genetic structures (e.g., Olguin & Mantelatto 2013; Sultana et al. 2018). Naturally, genetic research cannot be carried out on extinct forms, which makes any workable subdivisions of the genus Pagurus even more difficult. This morphological similarity amongst genetically diverse species is most likely a reflection of functional morphology. Particularly in paguroids, the shell has a marked impact on cheliped shape, and most hermit crabs inhabit comparable mollusks, which explains the closely comparable morphology of the chelipeds. In the fossil record, isolated paguroid chelipeds (mostly propodi) are quite common, whereas carapaces are extremely rare. In view of this, it is highly unlikely that the difficulties surrounding the ‘lump’ taxon Pagurus can be resolved on the basis of extinct forms., Published as part of Wallaard, Jonathan J. W., Fraaije, René H. B., Van Bakel, Barry W. M., Nance, John R., Lindholm, Adam & Jagt, John W. M., 2023, New hermit crab species (Anomura, Paguroidea) from the upper Miocene St Marys Formation of Maryland (USA), preserved in their host shells, pp. 389-397 in Zootaxa 5227 (3) on pages 391-392, DOI: 10.11646/zootaxa.5227.3.7, http://zenodo.org/record/7518846, {"references":["Conrad, T. A. (1832) Fossil shells of the Tertiary formations of North America, illustrated by figures drawn on stone by T. A. Conrad, 1 (2), 21 - 28. [reprinted by Harris, G. D., 1893 and by the Paleontological Research Institution, Ithaca, New York, 1963]","Ward, L. W. & Andrews, G. W. (2008) Stratigraphy of the Calvert, Choptank, and St. Mary's formations (Miocene) in the Chesapeake Bay area, Maryland and Virginia. Virginia Museum of Natural History Memoir, 9, 1 - 60.","Kidwell, S. M., Powars, D. S., Edwards, L. E. & Vogt, P. R. (2015) Miocene stratigraphy and paleoenvironments of the Calvert Cliffs, Maryland. Bulletin of the Geological Society of America, 40, 231 - 279.","Provenzano Jr., A. J. (1959) The shallow-water hermit crabs of Florida. Bulletin of Marine Science, 9 (4), 349 - 420.","Henderson, J. R. (1888) Report on the Anomura collected by H. M. S. \" Challenger \" during the years 1873 - 76. Scientific results of the exploratory voyage of HMS Challenger, Zoology, 27, i - xi + 1 - 221 pp., 21 pls.","Linnaeus, C. (1758) Systema naturae per regna tria naturae, secundumclasses, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Vol. 1. Editio 10. Reformata. Laurentius Salvius, Holmiae, 824 pp.","Hyzny, M. & Dulai, A. (2021) Badenian decapods of Hungary, GeoLitera Publishing House, Institute of Geosciences, University of Szeged, Szeged, 300 pp.","Olguin, N. & Mantelatto, F. L. (2013) Molecular analysis validates of some informal morphological groups of Pagurus (Fabricius, 1775) (Anomura: Paguridae) from South America. Zootaxa, 3666 (4), 436 - 448.","Sultana, Z., Asakura, A., Kinjo, S., Nozawa, M., Nakano, T. & Ikeo, K. (2018) Molecular phylogeny of ten intertidal hermit crabs of the genus Pagurus inferred from multiple mitochondrial genes, with special emphasis on the evolutionary relationship of Pagurus lanuginosus and Pagurus maculosus. Genetica, 146 (4), 369 - 381."]}

Two new species of hermit crab are recorded from the upper Miocene (Tortonian) St. Marys Formation of Maryland, named Pagurus hazenorum n. sp. and Paguristes timoni n. sp. and assigned to the families Paguridae Latreille, 1802, and Annuntidiogenidae Fraaije, 2014, respectively. Both new species are morphologically close to present-day congeners, but can be differentiated on details of ornament (tubercles, granules and teeth).

Eutrichopagurus crassoculus n. sp. [New Japanese name: Kurayami-yadokari] (Figs. 1–4) Type material. Holotype: RUMF-ZC 6115 (HD 2020-56), male (sl 1.2 mm), Hedo Dome (= Ginama) cave, Kunigami, Okinawa Island, Ryukyu Islands, zone 2, 3–5 m depth, 24 September 2020, SCUBA, collected by Y. Fujita & T. Fujii. Paratype: RUMF-ZC 6116 (HD 2020-54), 1 male (sl 1.2 mm), same data as in holotype. Description. Eleven pairs of deeply quadriserial gills. Shield (Fig. 1A, B) subtriangular in general outline, 1.1–1.2 times as long as wide; anterior margin between rostrum and lateral projections concave; anterolateral margins sloping; posterior margin roundly truncate, slightly concave on median part; dorsal surface slightly convex transversely, with 1 median, 1 submedian, and 1 lateral pairs of few short setae on anterior half. Rostrum triangular, terminating in acute tip, distinctly overreaching lateral projections. Lateral projections obtusely triangular, each with short marginal spine. Posterior carapace (Fig. 1A) with lateral lobes very narrow. Cardiac sulci not discernible. Sulci cardiobranchiales extending to posterior carapace margin, converging posteriorly. Posteromedian and posterolateral plates poorly calcified; branchiostegites membranous, almost glabrous. Ocular peduncle (including cornea) (Fig. 1B, C) stout, about half-length of shield, widest at about midlength, with sparse tufts of setae distally on each dorsomesial surface; cornea greatly reduced, rounded on distal margin, much narrower than peduncle; lateral surface strongly convex on proximal half and concave and somewhat decalcified on distal part including cornea (in preserved condition, showing strongly concave appearance, but in fresh condition, only weakly concave; Fig. 4A); mesial surface flattish, with bluntly delimited dorsomesial margin. Ocular acicle ovate, with small submarginal spine reaching proximal 0.2 of ocular peduncle; dorsal surface flattish. Interocular lobe separated from ocular acicles, overhung by rostrum, visible in dorsal view; anterior surface slightly convex. Antennular peduncle (Fig. 1B, D) long, when fully extended, overreaching distal corneal margin by full length of article 3 and distal one-third of article 2. Article 3 3.2 times as long as high, approximately 2.1 times as long as article 2, somewhat widened distally, with prominent tuft of long setae (length subequal to that of dorsal flagellum) on dorsodistal margin. Article 1 with distolateral margin not markedly produced; statocyst lobe slightly inflated, with small spine on lateral face. Dorsal flagellum 1.4 times longer than peduncular article 3, consisting of short aesthetasc-bearing proximal portion (about 10 articles) and long distal portion (about 10 articles, about 2.8 length of aesthetasc-bearing portion); ventral flagellum about half length of dorsal flagellum, consisting of about 10 articles. Antennal peduncle (Fig. 1B, E) overreaching distal corneal margin by nearly full length of article 5. Article 5 slightly flattened, with few setae marginally. Article 4 with few short setae ventromesially. Article 3 unarmed but with oblong capsule-like structure and few short setae on ventromesial distal margin. Article 2 dorsolateral distal angle produced, barely reaching midlength of article 4, terminating in simple spine, bearing few distal setae; dorsomesial distal angle with small spine; ventromesial margin with few short setae. Article 1 with minute distal spine on lateral surface; ventromesial distal margin somewhat produced anteriorly, but without armature. Antennal acicle overreaching distal corneal margin by distal one third length and reaching midlength of peduncular article 5, terminating in small spine; dorsomesial margin with row of sparse setae. Antennal flagellum (Fig.1F) 3.1–3.3 times shield length, overreaching extended right cheliped; each article with 0–3 short setae on distal margin. Mouthparts not dissected. Maxilliped 3 (Fig. 1G, H) moderately stout; carpus and merus unarmed; ischium with crista dentata composed of about 10 small closely set corneous teeth and 1 accessory tooth, dorsal margin with minute distal spine; basis-ischium fusion incomplete; basis with few minute denticles on ventromesial margin; exopod reaching slightly short of distal margin of carpus. Chelipeds (Fig. 2A, B, E, F) subequal in length, dissimilar with right much more robust than left. Right cheliped (Fig. 2A–D) moderately stout, moderately large compared to body. Chela elongate subovate in dorsal view, 1.8 times as long as wide (greatest width at midlength of palm), 1.7 times longer than carpus; dorsomesial margin somewhat narrowing distally; dorsolateral margin gently arched. Dactylus 0.7 length of palm, weakly curved in dorsal and mesial views, with sparse tufts of setae on surfaces, terminating in small corneous claw; dorsal and mesial surfaces proximally with sparse granules, dorsomesial margin not delimited; occlusal margin with 3 subacute calcareous teeth on submedian part and row of small corneous teeth on distal concaved part. Palm with sparse short to moderately long setae and covering of coarse granules on surfaces, granules on fixed finger sparse; dorsomesial margin delimited by row of short granular ridges; dorsolateral margin weakly delimited; dorsal and ventral surfaces gently convex. Fixed finger terminating in small corneous claw; occlusal margin with low rounded calcareous tooth proximally and prominent roundly triangular calcareous tooth subdistally, concaved distal part with row of small corneous teeth. Carpus slightly widened distally in dorsal view, 1.4–1.5 times longer than distal width, 0.9 length of merus, bearing sparse bristle-like setae on dorsomesial and dorsomesial margins and short transverse ridges and granules dorsally on mesial and lateral surfaces; few short setae on ventral surface; all surfaces with coarse granules, fewer on dorsal surface; dorsomesial margin with 3 or 4 distal spines followed by some short granular ridges; dorsolateral margin with blunt distal projection followed by some short granular ridges; mesial surface dorsally with 2 distal spines and few short granular ridges, distomesial margin granular; lateral surface with few short granular ridges dorsally and distal small spine ventrally, distolateral margin with row of coarse granules; ventral surface convex. Merus with very low, short transverse ridges and some bristle-like and simple setae on dorsal surface, dorsodistal margin unarmed; mesial surface with coarse granules and few distal bristle-like setae ventrally, ventromesial margin with 2–4 distinct distal spines followed by some short ridges or minute spines; lateral surface with few short setae and short granular ridges and single granules ventrally; ventrolateral margin 3 spines on distal half followed by some short ridges; ventral surface slightly convex on proximal half, with coarse granules. Ischium with sparse setae on dorsodistal margin and ventral surface; ventromesial margin unarmed. Coxa laterally with minute distal spine. Left cheliped (Fig. 2E–H) slender. Chela 2.7–2.9 times longer than wide (greatest width at midlength of palm), 1.3–1.5 times longer than carpus; dorsolateral margin weakly undulate on distal two-thirds Dactylus 1.5 times longer than palm, gently curved distally in dorsal view, terminating in small corneous claw; surfaces with sparse setae, dorsal surface proximally with coarse granules, otherwise nearly smooth; mesial surface proximally with arc of granules, dorsomesial margin not delimited; occlusal margin with row of minute corneous teeth (teeth on proximal half widely to narrowly spaced, those on distal half contiguous). Palm with sparse setae on dorsal and ventral surfaces; dorsal surface convex, elevated with some proximal subacute or spinulose tubercles on midline, covered with minute granules, dorsomesial and dorsolateral margins each delimited by row of small tubercles; lateral surface covered with granules; ventral surface gently convex, nearly smooth. Fixed finger distinctly curved distally in dorsal view, with scattered setae on dorsal and ventral surfaces, terminating in small corneous claw; occlusal margin bordered with thin corneous plate. Carpus slightly widened distally in dorsal view, 2.8–3.2 times longer than distal width, 0.9 length of merus; dorsolateral and dorsomesial margins with 4 (1 distal and 3 median) and 2 distal spines followed by few short ridges, respectively, spines and short ridges bearing bristle-like and simple setae; mesial surface smooth, with few bristle-like setae dorsally and distally; lateral surface with some scaley ridges medially, distolateral margin with row of small tubercles and few short bristle-like setae; ventrodistal margin with 2 small distal spines; ventral surface convex, with few very short setae. Merus with row of short ridges bearing few bristle-like and simple setae on distal half of dorsal surface, dorsodistal margin unarmed; mesial surface smooth, with few very short setae ventrally, ventromesial margin with row of 4 or 5 small spines and terminal bristle-like setae on distal half and with some short somewhat elevated ridges and bristle-like setae on proximal half; lateral surface with sparse short ridges bearing short setae, ventrolateral margin with 2 or 3 small spines on distal one third followed by some short somewhat elevated ridges; ventral surface flattish, bearing few short setae. Ischium unarmed, with few setae. Coxa laterally with minute distal spine. Ambulatory legs (Fig. 3A–D) moderately long and slender; surfaces mostly smooth. Dactyli 1.0–1.1 times as long as propodi, in dorsal view slightly curved mesially, in lateral view slightly curved ventrally; dorsal margins each with irregularly arranged row of setae, setae on distal one-third more closely set than on those on remaining part; lateral and mesial faces almost glabrous; ventral margins each with row of 3 or 4 (second) and 5 or 6 (third) slender corneous spines. Propodi distinctly longer than carpi, slightly narrowing distally, 5.0–5.1 times as long as maximum high; dorsal surfaces each with sparse setae; lateral and mesial faces glabrous; ventral margins each with 1 or 2 slender corneous spines at distal end and 1 or 2 corneous spines on median one third. Carpi unarmed, with sparse setae on dorsal surfaces; ventrodistal margin unarmed. Meri 3.6–3.8 (second) and 3.0–3.9 (third) times as long as maximum high, with sparse setae on dorsal surfaces; lateral surfaces almost glabrous; ventral margins with 1–3 small spines on posterior half (second) and unarmed (third). Ischia unarmed, with sparse tufts of setae distally on dorsal and ventral margins. Pereopod 4 (Fig. 1I) semichelate. Dactylus slightly curved. Propodus with rasp consisting of single row of corneous scales. Carpus unarmed on dosrsal surface. Dactylus to merus with sparse tufts of setae on dorsal surfaces, dorsodistal tuft of setae on merus prominent. Pereopods 5 chelate. Coxae (Fig. 1J–L) asymmetrical; right coxa with long, filamentous sexual tube (about 4.7 times of coxal length) directed posterolaterally and recurved toward anterior between dorsal surface of ischium and base of pleon, with hooked part on about distal one third, prominent tuft of setae at base of sexual tube; left coxa with very short sexual tube, directed mesially and tapering distally. Thoracic sternite 6 anterior lobe (Fig. 1M) transversely ovate, with pair of short setae anterolaterally. Thoracic sternite 8 (Fig. 1J) consisting of 2 contiguous lobes. Pleon dextrally twisted. Male with unpaired, unequally biramous left pleopods 3–5. Uropods markedly asymmetrical, protopods unarmed. Telson (Fig. 1N) with lateral indentations at posterior one-third; posterior lobes subtriangular, terminal margins oblique, each with 3–5 minute acute or blunt spines, posterolateral margins each with fringe of long setae. Coloration. In fresh condition, body and appendage are entirely translucent white with pale brown tint (Fig. 4). Distribution. So far only known from the type locality, Okinawa Island (Ryukyu Islands, southwestern Japan). Habitat. The two type specimens were obtained from the area between “main tube” zone and “innermost part” zones in Hedo Dome cave (cf. Osawa & Fujita 2019), having an anchialine environment with salinity cline. They each carried a shell of gastropod referred to an unidentified species of the genus Collonista Iredale, 1918 (Fig. 4B; H. Kubo, personal communication). Numerous empty and living shells of that species were found in the same environment of the cave. Prior to this study, hermit crabs found in Hedo Dome cave included 12 species (Osawa & Fujita 2019): Aniculus retipes Lewinsohn, 1982; Paguristes jalur Morgan, 1992; Pseudopaguristes shidarai Asakura, 2004 (Diogenidae, three species); Catapaguroides foresti McLaughlin, 2002; C. longior Komai, Yamada & Shirakawa, 2010; Pagurixus longipes Osawa, Fujita & Okuno, 2006; P. nomurai Komai & Asakura, 1995; Pylopaguropsis bellula Osawa & Okuno, 2007; P. fimbriata McLaughlin & Haig, 1989; P. granulata Asakura, 2000; P. keijii McLaughlin & Haig, 1989; and P. speciosa McLaughlin & Haig, 1989 (Paguridae, nine species). The present new species represents the 13th hermit crab species found in the cave. Among these species, only Catapaguroides foresti, C. longior, and Pylopaguropsis granulata occurred in “silty room” zone leading to “innermost part” zone of Hedo Dome cave. The other species were found in “main tube” zone and the present new species is obtained from the area adjacent to “innermost part” zone. Etymology. The specific name is derived from the combination of the Latin, crassus (= stout) and oculus (= eye), in reference to the inflated proximal portion of the ocular peduncle of the new species. Used as a noun in apposition. Remarks. In the preserved condition, the ocular peduncles of both the holotype and a paratype available for study have a strongly concave appearance on each distolateral margin including the cornea. Nevertheless, this condition is likely due to shrinkage by ethanol preservation because the ocular peduncles of the fresh specimens are seemingly only weakly concave on that margin (Fig. 4A). Meanwhile, the two type specimens have an oblong capsule-like structure on the ventromesial distal margin of each of the left and right antennal article 3 (Fig. 1E). Similar capsulelike structures have been reported in Trichopagurus asper Komai & Poupin, 2012 and T. tenuidactylus Komai, 2013; such several structures are present on the ventral surfaces of both cheliped meri and only a single structure is present on the ventromesial margin of the right cheliped merus in the two species, respectively. Komai & Poupin (2012) considered they possibly represent egg sacs of other invertebrates or parasites, but it is unknown if the capsule-like structures are identical among Komai & Poupin’s (2012), Komai’s (2013), and the present specimens, and if they might be actually external ornamentation belonging to the hermit crabs. In their description of Eutrichopagurus granulimanus Komai, Rahayu & Fujita, 2021 from Thunderdome Cave, a submarine cave of Christmas Island in the southeastern Indian Ocean, Komai et al. (2021) discussed the supposed morphological distinctions between the genera Eutrichopagurus and Cestopagurus Bouvier, 1897. As in Komai et al.’s (2021) species, the assignment of the present new species to the genus Eutrichopagurus is considered provisional, because only the male specimens were available for study, and the original diagnosis of the genus was based only on female characters. The present new species has diagnostic characters of Eutrichopagurus including eleven pairs of deeply quadriserial phyllobranchiate gills, a prominent tuft of setae on the dorsodistal margin of the article 3 of the antennular peduncle, and the posterolateral margins of the telson each bearing a tuft of long setae (cf. Komai 2015; Komai et al. 2021). The right sexual tube of the new species is directed posterolaterally and filamentous in shape as described in E. granulimanus, whereas that of E. shirakawai Komai, 2015, the type species of the genus and described from shallow subtidal waters around Okinawa Island, Ryukyu Islands, is unknown because no male of the species has been recorded. Eutrichopagurus is also substantially similar to Trichopagurus de Saint Laurent, 1968 in having the strongly produced triangular rostrum, a distinct tuft of setae on each posterolateral margin of the telson and the male right sexual tube being directed posterolaterally, but the deeply quadriserial, instead of biserial, gills distinguish the former from the latter (cf. Komai & Osawa 2005; Komai & Poupin 2012; Komai 2013, 2015). Among two known species of the genus Eutrichopagurus, E. crassoculus n. sp. may be closer to E. shirakawai Komai, 2015 in having reduced corneas basally bearing sparse setae and no small corneous spines or bristle-like setae on the dorsal surface of the meri of the ambulatory legs, but is distinguishable by the following numerous characters. The proximolateral margin of each ocular peduncle is strongly convex in E. crassoculus n. sp., whereas it is gently convex in E. shirakawai. The ocular acicle is short and ovate in the new species, instead of elongate and narrowly triangular in E. shirakawai. The antennular peduncle overreaches the distal corneal margin by the full length of the article 3 and the distal one third of the article 2, rather only approximately the full length of the article 3 in E. shirakawai. The antennal flagellum has at most three short setae on the distal margin of each article, whereas three to five, short and long setae are present on the distal margin, which make the flagellum somewhat setose, in E. shirakawai. The merus of maxilliped 3 is unarmed on both the dorsal and ventral margins, but it has distinct dorsodistal and ventromedian spines in E. shirakawai (cf. Komai 2015: fig. 1B, E, F). The right cheliped is proportionally much shorter in E. crassoculus n. sp. than in E. shirakawai; the chela and carpus are 1.8 versus 2.0 and 1.4–1.5 versus 2.1 times longer than the distal widths, respectively. The dactylus of the left cheliped is clearly longer than the palm in E. crassoculus n. sp., than in E. shirakawai; it is 1.5 versus 0.9 length of the palm. The merus of both chelipeds of E. crassoculus n. sp. has sparse bristle-like setae on the dorsodistal margin and adjacent to the ventromesial distal margin, but such setae are absent in E. shirakawai. The ambulatory legs are mostly smooth on all the surfaces, instead of the entire surfaces of the dactylus to carpus and the ventral parts of the lateral surfaces of the merus with numerous fine granules (cf. Komai 2015: figs. 2–4). Besides the strongly inflated proximolateral margin of the ocular peduncle, the reduced corneas, and the absence of small corneous spines or bristle-like setae on the dorsal surface of the ambulatory meri, E. crassoculus n. sp, Published as part of Osawa, Masayuki & Fujita, Yoshihisa, 2022, A new species of the genus Eutrichopagurus Komai, 2015 (Crustacea: Decapoda Anomura: Paguridae) from a submarine cave in the Ryukyu Islands, southwestern Japan, pp. 440-450 in Zootaxa 5214 (3) on pages 441-447, DOI: 10.11646/zootaxa.5214.3.6, http://zenodo.org/record/7389472, {"references":["Osawa, M. & Fujita, Y. (2019) Submarine cave hermit crabs (Crustacea: Decapoda: Anomura: Paguroidea) from three islands of the Ryukyu Islands, southwestern Japan. Zootaxa, 4560 (3), 463 - 482. https: // doi. org / 10.11646 / zootaxa. 4560.3.3","Iredale, T. (1918) Molluscan nomenclatural problems and solutions. No. 1. Proceedings of the Malacological Society of London, 13 (1 - 2), 28 - 40. https: // doi. org / 10.1093 / oxfordjournals. mollus. a 063674","Lewinsohn, C. (1982) Aniculus retipes n. sp. ein neuer Einsiedlerkrebs aus dem Roten Meer (Decapoda, Anomura). Crustaceana, 42 (1 - 2), 76 - 82. https: // doi. org / 10.1163 / 156854082 X 00713","Morgan, G. J. (1992) The hermit crabs (Crustacea: Decapoda: Coenobitidae, Diogenidae, Paguridae) of Christmas and Cocos (Keeling) Islands, Indian Ocean, with description of a new species of Paguristes. Raffles Bulletin of Zoology, 49 (2), 163 - 174.","Asakura, A. (2004) Pseudopaguristes shidarai, a new species of hermit crab (Crustacea: Decapoda: Diogenidae) from Japan, the fourth species of the genus. Proceedings of the Biological Society of Washington, 117 (2), 153 - 168.","McLaughlin, P. A. (2002) A new species of the genus Catapaguroides (Decapoda: Anomura: Paguroidea: Paguridae) from Guam, Micronesia. Crustaceana, 75 (3 - 4), 495 - 504. https: // doi. org / 10.1163 / 156854002760095543","Komai, T., Yamada, Y. & Shirakawa, N. (2010) A new hermit crab species of the genus Catapaguroides A. Milne-Edwards & Bouvier (Crustacea: Decapoda: Anomura: Paguridae) from the Ryukyu Islands, Japan, and additional record of C. foresti McLaughlin. Zootaxa, 2690 (1), 32 - 42. https: // doi. org / 10.11646 / zootaxa. 2690.1.3","Osawa, M., Fujita, Y. & Okuno, J. (2006) Two new species of Pagurixus (Crustacea: Decapoda: Anomura: Paguridae) from submarine caves of the Ryukyu Islands, southwestern Japan. Zootaxa, 1148 (1), 27 - 45. https: // doi. org / 10.11646 / zootaxa. 1148.1.2","Komai, T. & Asakura, A. (1995) Pagurixus nomurai, new species, and addition al record of Pagurixus maorus (Nobili, 1906), hermit crabs from Kume-jima Island, the Ryukyus, Japan (Decapoda: Anomura: Paguridae). Journal of Crustacean Biology, 15 (2), 341 - 354. https: // doi. org / 10.2307 / 1548961","Osawa, M. & Okuno, J. (2007) New species of the genus Pylopaguropsis (Crustacea: Decapoda: Anomura: Paguridae) from the Ryukyu Islands, southwestern Japan, with notes on two poorly known pagurids. Species Diversity, 12 (1), 29 - 46. https: // doi. org / 10.12782 / specdiv. 12.29","McLaughlin, P. A. & Haig, J. (1989) On the status of Pylopaguropsis zebra Henderson, P. magnimanus (Henderson), and Galapagurus teevanus Boone, with descriptions of seven new species of Pylopaguropsis (Crustacea: Anomura: Paguridae). Micronesica, 22 (2), 123 - 171.","Asakura, A. (2000) A review of Japanese species of Pylopaguropsis Alcock, 1905 (Decapoda: Anomura: Paguridae). Crustacean Research, 29, 70 - 108. https: // doi. org / 10.18353 / crustacea. 29.0 _ 70","Komai, T. & Poupin, J. (2012) Two new species of shallow-water hermit crabs (Crustacea: Decapoda: Paguridae) from Mayotte Island, southwestern Indian Ocean. Zootaxa, 3277 (1), 56 - 68. https: // doi. org / 10.11646 / zootaxa. 3277.1.4","Komai, T. (2013) Additional records of the pagurid hermit crab genus Trichopagurus de Saint Laurent, 1968 (Crustacea: Decapoda: Anomura), with description of a new species from the Philippines. Zootaxa, 3670 (2), 274 - 282. http: // dx. doi. org / 10.11646 / zootaxa. 3670.2.10","Komai, T., Rahayu, D. L. & Fujita, Y. (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, 378 - 402. https: // doi. org / 10.26107 / RBZ- 2021 - 0059","Bouvier, E. L. (1897) Sur deux paguriens nouveaux trouves par M. Coutiere dans le recif madreporique, Djibouti. Bulletin du Museum national d'Histoire naturelle, Paris, 6, 229 - 233.","Komai, T. (2015) A new genus and new species of Paguridae (Crustacea: Decapoda: Anomura) from shallow subtidal waters in Okinawa Island, the Ryukyu Islands, Japan. Zootaxa, 3918 (2), 250 - 260. http: // dx. doi. org / 10.11646 / zootaxa. 3918.2.6","Saint Laurent, M. de. (1968) Revision des genres Catapaguroides et Cestopagurus et description de quatre genres nouveaux. II. Cestopagurus Bouvier (Crustaces Decapodes Paguridae). Bulletin du Museum national d'Histoire naturelle, Paris, 2 e Serie, 42, 210 - 222.","Komai, T. & Osawa, M. (2005) A new species of Trichopagurus de Saint Laurent (Crustacea: Decapoda: Anomura: Paguridae) from the Ryukyu Islands, and redescription of T. trichophthalmus (Forest). Zootaxa, 801 (1), 1 - 20. https: // doi. org / 10.11646 / zootaxa. 801.1.1"]}

A new hermit crab species of the family Paguridae is described on the basis of two male specimens from Hedo Dome, a submarine cave located on the north coast of Okinawa Island, Ryukyu Islands, southwestern Japan. The assignment of the new species to the genus Eutrichopagurus Komai, 2015 is based on the structure of the gills and right male sexual tube, the article 3 of the antennular peduncle with a prominent tuft of setae on the dorsodistal margin, and the posterior lateral margins of the telson each bearing a prominent tuft of setae. Among two known congeners, Eutrichopagurus crassoculus n. sp. may be closer to the type species of the genus, E. shirakawai Komai, 2015, in having greatly reduced corneas, basally bearing sparse setae, and no small corneous spines or spiniform setae on the dorsal surface of the meri of the ambulatory legs, but is distinguishable by the morphology of the ocular peduncles, ocular acicle, antennular peduncle, and chelipeds.

Pagurus pectinidactylus n. sp. (Figs. 2–4) lsid:zoobank.org:act: E87A7D6A-9982-43A6-B2D3-AE1D821153FF Type material. Holotype: ♂ sl. 3.2 mm (IEOCD-BR/2979), Mauritania, off Lemhaisrat, 19°00′09.7″N 16°23′38.0″W, sand, 21 m depth, 03 June 2012. Paratypes: 2 ovigerous ♀, sl. 3.9 and 2.9 mm (IEOCD-BR/2978), Mauritania, north of Nouakchott, 18°36′55.4″N 16°18′32.0″W, sand, 30 m depth, 03 June 2012. Description. Shield (Fig. 2A) flattened dorso-ventrally, broader than long, with tufts of short setae along shallow paragastric grooves and numerous low blister-like tubercles only visible when stained with methylene blue. Eleven pairs of phyllobranchia (Fig. 2B) with arthrobranchia on Mxp3, on cheliped and pereiopods 2–4, with one well-developed pleurobranchia on pereiopod 4. Rostrum broadly triangular, tip slightly sloping downwards, with small tubercle distally and produced to or slightly beyond level of obtusely triangular lateral projections; frontal margin between lateral projections thickened; lateral projections each armed with minute spine. Posterior carapace (Fig. 2D) membranous except for weakly calcified median and submedian parts, both with low blister-like tubercles and tufts of short setae; branchial region with tufts of simple setae. Ocular peduncles 0.7–0.8 length of shield, slightly swollen medially, with row of short setae medially; conspicuous oblique calcified scale covering the latero-proximal part; corneas slightly dilated; ocular acicles ovate, separated basally by 0.5 width of 1 acicle, terminating subacutely, with small submarginal spine and some setae on distal margin; dorsal surface shallowly concave medially; lateral extensions subquadrate, well-developed. Antennular peduncles (Fig. 2A, C) overreaching ocular peduncles by 0.3–0.4 length of ultimate segment; ultimate segment almost twice as long as penultimate segment, slightly widened distally, with tufts of long setae, one near distal margin, second medially; additional simple setae on proximal 1/3, one dorsal and one lateral; penultimate segment with few short setae; basal segment with lateral margin produced into blunt projection with narrow, blunt distal end; ventromesial distal margin produced as rounded projection; statocyst lobe unarmed; ventromesial distal angle unarmed. Antennal peduncles (Fig. 2A) overreaching ocular peduncles by approximately 0.3–0.4 length of fifth segment, and slightly longer than antennular peduncles. Second segment with dorsolateral distal angle strongly produced, reaching to 3/4 of fourth peduncular segment, terminating in strong spine, mesial margin with at least 10 additional small spines; dorsomesial distal angle with acute spine. Antennal acicles arcuate, reaching to proximal 0.4–0.5 of ultimate peduncular segment, with small terminal spine; mesial margin with row of rather stiff setae. Third maxiliped (Fig. 2E) moderately stout; dactylus about 0.8 length of propodus; carpus and merus unarmed; ischium with crista dentata with about 8 corneous teeth increasing in size and more widely spaced proximally, with 1 strong accessory tooth; basis with 2 minute denticles on mesial margin; exopod reaching distal margin of carpus. Chelipeds unequal and dissimilar, right appreciably larger than left. Male right cheliped (Fig. 3A–C) moderately stout, appreciably elongated. Chela subquadrate in dorsal view, about twice as long as wide. Dactylus approximately same length as palm, not overlapped by fixed finger when closed; dorsal surface not elevated, smooth except for short row of small spines proximally; longitudinal rows of tufts of setae on dorsal surface and longitudinal row of stiff setae along cutting edge; dorsomesial margin defined by single row of small, obtuse tubercles, with associated tufts of moderately long stout setae; ventral surface smooth, with 3 rows of tufts of long stout setae; cutting edge with row of 7 rounded calcareous teeth, smallest medially, terminating in small corneous claw. Palm including fixed finger 1.7 times longer than carpus; with row of blunt spines on dorso-mesial margin; dorsal surface flat, smooth, with clumps of stout short setae forming circular tufts arranged in longitudinal rows (Fig. 3F); dorsolateral margin elevated, clearly delimited by row of closely-spaced acute to subacute spines with associated short setae; space between spines widening distally, disappearing near tip; dorsomesial margin elevated, delimited by single row of spines with associated tufts of long setae; ventral surface slightly convex, smooth, with sparse tufts of long setae arranged in longitudinal rows. Cutting edge of fixed finger with 8 or 9 calcareous teeth, smallest proximally, terminating in small corneous claw. Carpus elongated, widened distally, about twice as long as maximum width and similar in length to merus; dorsal surface smooth, with tufts of stout short setae arranged in rows more dense on lateral and mesial margins; dorsomesial margin slightly elevated and clearly delimited with row of oblique moderately strong blunt or acute spines; dorsodistal margin unarmed, with rows of setae of different size; dorsolateral margin not well-delimited, with several rows of stout short setae; lateral surface slightly convex, perpendicular, smooth and almost glabrous; mesial face slightly concave, with scattered tufts of long simple setae, ventromesial margin forming a wind-like protuberance with spines continuing the dorsomesial row; ventral surface convex, with scattered tufts of moderately long setae. Merus subtriangular; dorsal surface with low protuberances with associated short setae; dorsodistal margin with 2 large and 1 smaller acute spines with associated short setae; lateral surface slightly convex, smooth, with few very short scattered setae; mesial surface slightly concave with scattered long setae; ventromesial margin smooth except for small spinulose area distally; ventrolateral margin not well-defined, rounded; ventral surface smooth, with scattered long setae. Ischium unarmed. Female right cheliped differs from males in length, being less elongated but similar in shape and armature to male. Male left cheliped (Fig. 3D, E) generally similar to right. Dactylus approximately 1.5 length of palm, dorsomesial margin with row of closely-spaced acute tubercles; dorsal surface smooth, with rows of tufts of moderately long setae; masticatory border toothless, except some very small proximally; rest of masticatory border bearing closelyspaced stout setae, forming a well-developed brush-like structure (Fig. 3D inset). Palm with row of subacute spines on dorsomesial margin, ending distally in two conspicuous spines; dorsal surface almost flat, unarmed; dorsolateral margin slightly raised and with row of closely-spaced subacute tubercles not extending to tip of fixed finger. Carpus with row of subacute oblique spines on dorsomesial margin; dorsal surface smooth, with longitudinal ridges of tufts of stiff setae; dorsodistal margin with several small spines. Merus with 2 spines on dorsodistal margin; ventromesial and ventrolateral margins each with row, or only few, very small blunt spinules or tubercles. Female left cheliped similar in shape to male, with more tubercles especially evident at dorsolateral surface of carpus, which is slightly elevated bearing some low tridentate tubercles with associated stiff setae, and merus, with dorsal surface crossed by rows of spinose sulcus, continuing along lateral and mesial surfaces, especially distal ones. Ambulatory legs (Fig. 4A, B) short and stout. Dactylus about same length (second) to 1.2 times longer than propodus (third) and about 5 times longer than broad, flattened laterally and gently curved ventrally terminating in strong corneous claw; lateral surface smooth, with very shallow longitudinal sulcus and few tufts of short setae on lower half; dorsal margin with irregular rows of tufts of short, thick setae, ending in row of long setae occupying distal 1/5; ventro-inner margins each with row of 5 or 6 (second) to 7 or 8 (third) strong corneous spines increasing in size distally, evenly distributed except most proximal of second pereiopod, which is more separated, and associated tufts of long setae. Propodus approximately 1.4 times longer than carpus (second and third); dorsal surfaces unarmed, each with multiple rows of short thick setae; lateral surface smooth, with longitudinal rows of short setae; ventral margins each with 3 corneous spines and tufts of short setae, denser near distal margin. Carpus with dorsal margin defined by row of small spines and associate tufts of short setae, with strong spine at dorsodistal margin; several rows of tufts of setae on lateral faces, short at upper half and near lower margin, longer at midline; ventral margin unarmed and glabrous. Merus with dentate dorsal margin, with associated rows of setae; lateral surface smooth and glabrous; ventral margins unarmed or with low protuberances or spinules, particularly on second pereiopods, and row of moderately long setae. Fourth pereiopods (Fig 4E) semichelate, subequal in length from left to right; dactylus with subterminal tuft of short setae on dorsal margin; carpus ending in conspicuous spine at distodorsal margin; stiff long setae and tufts of setae on dorsal margin of propodus to carpus and distodorsal and ventromesial margin of merus. Dactylus nearly straight, with convex dorsal margin, terminating in small, strongly-curved corneous claw; ventral margin with closely-set, microscopic corneous teeth; propodal rasp consisting of single row of corneous scales. Fifth pereiopods chelate, propodal rasp occupying distal half of segment. Sternite of somite XII in males (thoracomere 6, third pereiopods) with roundly subrectangular anterior lobe (Fig. 2F), bearing setae of different sizes on anterior margin. Sternite of somite XIV (thoracomere 8, fifth pereiopods) with widely separated lobes in males, each with moderately long setae (Fig. 4C); coxae of male each with gonopore partially masked by tuft of setae. Sternite of somite XII of females, with subquadrate single central lobe bearing moderately long simple setae (Fig. 4D); coxa of females each with gonopore, and associated tufts of setae above, without masking them. Males with 3 uniramous unpaired left pleopods; females with slightly unequally biramous 2-4, fifth uniramous.. Telson (Fig. 4F) with lateral incision indicating anterior and posterior portions; posterior lobes slightly asymmetrical, subquadrate, left slightly larger than right, separated by very small median cleft; terminal margins each with row of calcareous large teeth alternating with small ones, extending into lateral margin on left lobe and to posterior half of right; few short setae associated with spines and some tufts of longer setae on lateral margins. Distribution. So far only know from two off-shore stations, 21–30 m depth, within Mauritanian waters, north of Nouakchott. Etymology. Derived from Latin pecten (= comb) and Greek δάχτμλος (dáctilos = finger), referring to the characteristic row of closely-spaced stout setae on the masticatory border of left cheliped dactylus, forming a welldeveloped brush-like structure. Taxonomic remarks. The new species is assignable to the informal Pagurus anachoretus group (cf. Forest 1978) as it concurs with the general definition of the group (Forest & Ngoc-Ho 1992; McLaughlin & Forest 1999; Komai & Rahayu 2004). This group includes 12 species at present: Pagurus anachoretus from the Mediterranean, P. anachoretoides, P.gordonae, P.laurentae and P.souriei from the tropical eastern Atlantic, P.emmersoni and P.liochele from South Africa, and the Indo-West Pacific P. decimbranchiae Komai & Osawa, 2001, P. fungiformis Komai & Rahayu, 2004, P. hedleyi (Grant & McCulloch, 1906), P. kulkarnii Sankolli, 1961 and P. moluccensis Haig & Ball, 1998 (see Forest 1978; Forest & Ngoc-Ho 1992; McLaughlin & Forest 1999). Four other species from the tropical eastern Atlantic, P. alcocki, P. dartevellei (Forest, 1958), P. fimbriatus and P. triangularis, also fit the definition of the P. anachoretus group except for the cheliped form (Forest 1978; Forest & Ngoc-Ho 1992; McLaughlin & Forest 1999; Komai & Rahayu 2004). Pagurus fraserorum described by Landschoff (2018) also shares the main characters of the group except for the shape of the right cheliped, and based on molecular results, it has been suggested that it may constitute a separate group, more related with P. boriaustraliensis and P. pitagsaleei. Notwithstanding, the new species shows enough morphological differences to avoid any confusion with the species of the group or any other congeners known so far. The oblique calcified scale present in the base of the peduncles, is not known to occur in any other species of Pagurus. The shape and armature of the chelipeds are diagnostic, with a subquadrate shape in dorsal view, clearly elongate. The palm surface is flat and smooth, but with numerous distinctive clumps of stout short setae forming circular tufts arranged in longitudinal rows. The masticatory border of the left cheliped dactylus is also very conspicuous, lacking teeth, but bearing instead a row of closely-spaced stout setae, forming a well-developed brush-like structure, which has not been described for any other species of Pagurus in the study area. Although those characters are sufficiently distinctive to avoid any confusions, the new species shows a closer morphological resemblance with some species of the anachoretus group, specifically with Pagurus liochele, P. emmersoni, P. triangularis, P. fimbriatus and P. similimanus. The first two are considered endemic to South African waters. The new species differs from the two South African congeners in having broader carapace and rostrum, longer ocular peduncles, and more ovate ocular acicles. The antennules are shorter in P. emmersoni, overreaching distal margin of corneas by approximately 0.2 length of antennular segment 3, while they are similar in P. pectinidactylus n. sp. and P. liochele, overreaching the ocular peduncles by approximately 0.3–0.4 length of antennular segment 3. Another distinctive character can be found in the antennal segment 2 dorsolateral distal angle, which is strongly produced in both P. liochele and P. pectinidactylus n. sp., with mesial margin more densely dentate in the new species with at least 10 small spines, while in P. liochele there are 1–5. Moreover, the new species has a longer palm, with the characteristic clumps of setae arranged in circles on dorsal surface instead of any tubercles or spines, character that has not been described in any of the other species. The pereiopods are stout but more elongated in the new species, with the dactylus longer than propodus, bearing 5 (second) to 7 (third) strong corneous spines on ventral margin. The sternite of third pereiopods anterior lobe is roundly rectangular in P. pectinidactylus n. sp. and P. emmersoni, although with differences in setation, while in P. liochele the shape of the sternite is subovate. The other three species share also some morphological characters, the last two even with a distribution relatively close to that of the new species (see introduction). P. fimbriatus differs in the rostrum, which is obtuse, not pointed and not thickened. The shield is as long as broad while in the new species is broader than long. The antennal scales are shorter in P. fimbriatus, reaching only the base of the cornea, while in the new species reach distal end of corneas. Another important character can be found at dorsolateral distal angle of the second antennal segment, which is strongly produced in P. pectinidactylus n. sp., reaching to 3/4 of fourth peduncular segment, terminating in strong spine and with mesial margin bearing at least 10 additional small spines; based on the descriptions and figures provided by Forest (1966), this character is not present in P. fimbriatus. Pagurus triangularis and the new species share a pointed rostrum, but the former (like P. fimbriatus) has a narrower shield and shorter antennal acicles, which does not reach the distal margin of the cornea (at most it reaches its base), and also has a shorter dorsolateral distal process at the second antennal segment. P. similimanus also has a narrower shield, and a rostrum that is less projected than in the new species. The ocular peduncles are also shorter in P. similimanus, reaching to midlength of antennular segment 3, and proximal 1/3 of antennal segment 5, while in the new species reach the distal 1/3 of the antennular segment 3 and antennal segment 5. The antennal acicle is much longer, clearly exceeding the cornea in P. similimanus while in the new species reaches the distal margin of the cornea. The dorsolateral distal process of the second antennal segment has 6–8 little teeth on mesial margin, while in the new species the number is higher (up to 10). The shape of the chelipeds is also different in all these species, with a variable degree of elongation that never reaches that of the new species. The dorsal surface of the chelipeds is flat and unarmed in P. pectinidactylus n. sp., and the characteristic pattern formed by the clumps of setae is not mentioned in any of the other Eastern Atlantic species, neither the diagnostic masticatory border of the dactyl of the left cheliped formed by strong, densely arranged setae instead of teeth., Published as part of Almón, Bruno, Cuesta, Jose A. & García-Raso, J. Enrique, 2022, A new species of hermit crab of the genus Pagurus Fabricius, 1775 (Crustacea: Anomura: Paguridae) from north-western Africa, pp. 426-440 in Zootaxa 5209 (4) on pages 430-436, DOI: 10.11646/zootaxa.5209.4.2, http://zenodo.org/record/7333828, {"references":["Forest J. (1978) Sur deux pagurides nouveaux de l'Atlantique tropical africain: Pagurus laurentae et Paguristes cyanops spp. nov. Bulletin du Museium national d'histoire naturelle, Paris, 3 e serie Zoologie, 356, 525 - 538.","Forest, J. & Ngoc-Ho, N. (1992) Desription de Pagurus dartevellei (Forest, 1958) (Crustacea, Decapoda, Paguridae). Bulletin du Museum national d'histoire naturelle Section A Zoologie, biologie et ecologie animales, 14, 217 - 227.","McLaughlin, P. A. & Forest, J. (1999) Hermit crabs of the genus Pagurus Fabricius (Crustacea, Decapoda, Paguridae) from south-eastern South Africa. Annals of the South African Museum, 105, 297 - 344.","Komai, T. & Rahayu, D. L. (2004) Redescription of Pagurus moluccensis Haig & Ball, 1988, with description of a new species of Pagurus from Indonesia, and taxonomic notes on the Pagurus anachoretus group (Crustacea: Decapoda: Anomura: Paguridae). Raffles Bulletin of Zoology, 52, 183 - 200.","Komai, T. & Osawa, M. (2001) A new distinctive species of pagurid hermit crab (Crustacea: Decapoda: Anomura) from Japan. Zoological Science, 18, 1291 - 1301. https: // doi. org / 10.2108 / zsj. 18.1291","Grant, F. E. & McCulloch, A. R. (1906) On a collection of Crustacea from the Port Curtis district, Queensland. Proceedings of the Linnean Society of New South Wales, 31 (1), 2 - 53.","Forest, J. (1958) Les Crustaces Anomoures du Musee royal du Congo belge. Revue de Zoologie et de Botanique Africaines, 58, 144 - 168.","Landschoff, J., Komai, T., du Plessis, A., Gouws, G. & Griffiths, C. L. (2018) MicroCT imaging applied to description of a new species of Pagurus Fabricius, 1775 (Crustacea: Decapoda: Anomura: Paguridae), with selection of three-dimensional type data. PLoS ONE, 13 (9), e 0203107. https: // doi. org / 10.1371 / journal. pone. 0203107","Forest, J., 1966. Crustaces Decapodes: Pagurides. In: Campagne de la Calypso dans le Golfe de Guinee et aux Iles Principe, Sao Tome ' et Annobon (1956). Annales de l'Institut Oceanographique de Monaco, 44, pp. 125 - 172."]}

Pagurus Fabricius, 1775 Remarks. Pagurus is the richest genus in the family Paguridae with 175 valid species (McLaughlin et al., 2010; Osawa, 2012; Komai & Rahayu, 2014; Komai et al., 2015b; Lima & Lemaitre, 2016; Lemaitre et al., 2017; Landschoff et al., 2018; Lima et al., 2019). In Singapore waters, this genus has been represented only by two species, P. kulkarnii Sankoli, 1962 and P. pergranulatus (Henderson, 1896) (Rahayu, 1996). In this study three more species were added to the pagurid fauna of Singapore, one of which is a new species., Published as part of Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, pp. 329-363 in Raffles Bulletin of Zoology 70 on page 352, DOI: 10.26107/RBZ-2022-0017, http://zenodo.org/record/7174641, {"references":["McLaughlin PA, Komai T, Lemaitre R & Rahayu DL (2010) Annotated checklist of anomuran decapod crustaceans of the world (exclusive of the Kiwaoidea and families Chirostylidae and Galatheidae of the Galatheoidea) Part I - Lithodoidea, Lomisoidea and Paguroidea. In: Low MEY & Tan SH (eds.) Checklists of Anomuran Decapod Crustaceans of the world (Exclusive of the Kiwaoidea and families Chirostylidae and Galatheidae of the Galatheoidea) and Marine Lobsters of the World. Raffles Bulletin of Zoology, Supplement 23: 5 - 107.","Osawa M (2012) A new species of the genus Pagurus Fabricius, 1775 (Crustacea: Decapoda: Anomura: Paguridae) from the Ryukyu Islands, southwestern Japan. In: Naruse T, Chan T-Y, Tan HH, Ahyong ST & Reimer JD (eds.) Scientific Results of the Marine Biodiversity Expedition - KUMEJIMA 2009. Zootaxa, 3367: 155 - 164.","Komai T & Rahayu DL (2014) New records and new species of the hermit crab genus Pagurus Fabricius, 1775 (Crustacea: Decapoda: Anomura: Paguridae) from the Phillipines. Raffles Bulletin of Zoology, 62: 620 - 646.","Komai T, Saito Y & Morin E (2015 b) A new species of the hermit crab genus Pagurus Fabricius, 1775 (Crustacea: Decapoda: Anomura: Paguridae) from shallow coastal waters in Japan, with a checklist of the East Asian species of the genus. Zootaxa, 3918 (2): 224 - 238.","Lima DJM & Lemaitre R (2016) A new species of hermit crab of the genus Pagurus Fabricius, 1775 (Crustacea: Anomura: Paguridae) from the southern Caribbean off Venezuela. Zootaxa, 4161 (3): 445 - 450. http: // doi. org / 10.11646 / zootaxa. 4161.3.12","Lemaitre R, Felder D L & Poupin J (2017) Discovery of a new micro-pagurid fauna (Crustacea: Decapoda: Paguridae) in the Lesser Antilles, Caribbean Sea. Zoosystema, 39 (2): 151 - 195.","Lima D, Tavarez M & De Mendoca JB Jr (2019) Paguroids (Decapoda: Anomura: Diogenidae and Paguridae) of the remote oceanic Archipelago Trindade and Martin Vaz, off southeast Brazil, with new records, description of three new species and zoogeographical notes. Zootaxa, 4694 (1): 1 - 63.","Sankoli KN (1962) On a new species of hermit crab Pagurus kulkarnii sp. nov. (Anomura: Paguridae). Journal of Zoological Society of India, 13: 136 - 142.","Henderson JR (1896) Natural history notes from H. M. \" Investigator \" Commander C. F. Oldham, R. N., commanding - Series II, No. 24. Reports on the Paguridae collected during the season 1893 - 1894. Journal of the Asiatic Society of Bengal, 65: 516 - 536.","Rahayu DL (1996) Notes on littoral hermit crabs (excluding Coenobitidae) (Crustacea: Decapoda: Anomura) mainly from Singapore and Peninsular Malaysia. Raffles Bulletin of Zoology, 44 (2): 335 - 355."]}

Spiropagurus spiriger (De Haan, 1849) (Fig. 14F) Pagurus spiriger De Haan, 1849: 206, pl. 49, fig. 2 (type locality: Japan). Spiropagurus spiriger; Alcock, 1905b: 118, pl. 13, fig. 1; Miyake, 1978: 137, fig. 54; Miyake, 1982: 122, pl. 41, fig. 5; Lewinsohn, 1982: 216, fig. 2; Baba, 1986: 211, fig. 155; Rahayu, 1996: 351; McLaughlin, 2002a: 448, fig. 9A; McLaughlin, Rahayu, Komai & Chan, 2007: 213, unnumbered figures. Material examined. 1 female, 3.8 mm (ZRC 2021.0262), st. TB96, near Eastern Bunkering A, 1°18. 140′N 104°04.221′E, beam trawl, 22.4–25.1 m, clay, 28 May 2013; 1 male, 2.5 mm (ZRC 2021.0263), st. TB97, 1°18. 425′N 104°04.607′E, beam trawl, clay, 22.4–22.7 m, 28 May 2013; 1 male, 3.8 mm (ZRC 2021.0264), DR09, Pasir Panjang, 01°16.229′N 103°45.358′E, 24 m, 12 June 2012. Colour. In general brownish cream with darker brown speckled on shield and ocular peduncles, setae yellowish white (Fig. 14F). Distribution. Bay of Bengal, Andaman Sea, Gulf of Thailand, East Indian Archipelago, Singapore, Malaysia, East China Sea, Japan, Taiwan, Northern Australia; 22–25 m, on sandy, muddy substrates., Published as part of Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, pp. 329-363 in Raffles Bulletin of Zoology 70 on page 359, DOI: 10.26107/RBZ-2022-0017, http://zenodo.org/record/7174641, {"references":["Alcock A (1905 b) Catalogue of the Indian decapod Crustacea in the collections of the Indian Museum. Part 2. Anomura. Fasc. 1. Pagurides. Indian Museum, Calcutta, xi + 197 pp.","Miyake S (1978) The crustacean Anomura of Sagami Bay. Biological Laboratory, Imperial Houshold, Tokyo, 200 pp. [English], 161 pp. [Japanese].","Miyake S (1982) Japanese Crustacean Decapods and Stomatopods in colour, vol. 1. Macrura, Anomura, Stomatopoda. First printing, Hoikusha, Osaka, vii + 261 pp., 56 pls. [in Japanese]","Lewinsohn C (1982) Eine neue art der Gattung Spiropagurus Stimpson (Decapoda: Anomura) aus dem Roten Meer. Crustaceana, 42 (1): 212 - 218.","Baba K (1986) Macrura Reptantia. Anomura, Brachyura. In: Baba K, Hayashi M & Toriyama K (eds.) Decapod crustacean from continental shelf and slope around Japan. The intensive research of unexploited fishery resources on continental slopes. Japan Fisheries Resource Conservation Association, Tokyo, pp. 148 - 231, 279 - 316.","Rahayu DL (1996) Notes on littoral hermit crabs (excluding Coenobitidae) (Crustacea: Decapoda: Anomura) mainly from Singapore and Peninsular Malaysia. Raffles Bulletin of Zoology, 44 (2): 335 - 355.","McLaughlin PA (2002 a) A review of the hermit crab (Decapoda: Anomura: Paguridea) fauna of southern Thailand, with particular emphasis on the Andaman Sea, and descriptions of three new species. In: Bruce N, Berggren M & Bussawarit S (eds.) Proceedings of the International Workshop on the Crustacea in the Andaman Sea, Phuket Marine Biological Center 29 November - 20 December, 1998. Phuket Marine Biological Center Special Publication, 23 (2): 385 - 460.","McLaughlin PA, Rahayu DL, Komai T & Chan T-Y (2007) A Catalog of the Hermit Crabs (Paguroidea) of Taiwan. National Taiwan Ocean University, 364 pp."]}

Spiropagurus Stimpson, 1858 Remarks. The species in the genus Spiropagurus is easily recognised by the presence of squamiform ridges or tubercles bearing marginal setae on the chelipeds and ambulatory legs, the presence of long, usually coiled, terminally blunt sexual tube on the coxa of left P5 of male, and the characteristic posterior lobes of the telson being acutely triangular. Seven species are recognised (Han et al., 2016), but only one species, Spiropagurus spiriger (De Haan, 1849), has been recorded from Singapore., Published as part of Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, pp. 329-363 in Raffles Bulletin of Zoology 70 on page 359, DOI: 10.26107/RBZ-2022-0017, http://zenodo.org/record/7174641, {"references":["Han Y-Y, An J-M & Sha Z-L (2016) A review of the genus Spiropagurus Stimpson, 1858 (Crustacea: Anomura: Paguridae) from the China Sea. Zootaxa, 4175 (1): 75 - 89."]}

Pagurus pitagsaleei McLaughlin, 2002 (Fig. 14C, D) Pagurus pitagsaleei McLaughlin, 2002a: 444 (type locality: Cape Panwa, Phuket, Thailand). Pagurus cf. boreoaustraliensis Rahayu & Komai, 2000: 30, figs. 4–8. (Not Pagurus boreoaustraliensis Morgan, 1990). Material examined. 1 male, 4.0 mm (ZRC 2021.0237), st. SD45, Channel between Lazarus and St John’s Island, 16.2 m, 23 May 2013; 1 male, 4.0 mm (ZRC 2021.0238), st. IT93 Pulau Jong, 1°12.901′N 103°47.194′E, 28 May 2013; 1 male, 4.9 mm (ZRC 2021.0239), st. IT95, Raffles Lighthouse, 01°09.600′N 103°44.456′E, intertidal reef, 28 May 2013; 1 ovigerous female, 3.1 mm (ZRC 2021.0240), st. IT108, Raffles Lighthouse, 01°09.600′N 103°44.456′E, intertidal reef, 29 May 2013; 1 male, 3.3 mm (MZB Cru 5221), st. SD133, South of Kusu Island, 11 m, 31 May 2013; 1 male, 4.5 mm (MZB Cru 5222), Pulau Jong, dive, coll. 7 July 2012; 1 ovigerous female, 3.4 mm (MZB Cru 5223), st. SW155, north lagoon of St John’s Island, 1°13.116′N 103°51.079′E, intertidal, 3 June 2013. Colour in life. Shield mottled with white and greenish blue, two bluish black blotches on each dorsal and anterior part of shield. Ocular peduncle bluish white, three short black incomplete stripes, with a shade of blue, proximally, two short black stripes distally, corneas grey. Antennular peduncle penultimate segment transparent blue with brown blotch, orange at articulation to ultimate segment; ultimate segment transparent blue, bright orange distally; flagellum bright orange. Antennal peduncle and antennal acicle white with dark blue spots. Chelipeds with palms and dactyls white with black and light brown blotches dorsally, lateral faces with broad black interrupted stripes, spines white, carpus and merus bluish white with large black stripes and blotches. P2 and P3 generally white, lateral face of each segment with different pattern of short black stripes, not reaching extremity of each segment (dactyl with one complete stripe and one interrupted stripe, propodi with two stripes with dorsolateral stripe interrupted, carpus with three stripes, merus with three stripes with dosolateral stripe interrupted), propodi, carpi, and meri each with faint shade of bluish band medially (Fig. 14C, D). Distribution. Northern and Western Australia, and now Singapore; 0–11 m, collected from intertidal reef, coral, and under stone on sandy muddy area. Remarks. Morphological characters and colour pattern of the specimens examined in this study agree well with the description of Pagurus pitagsaleei by McLaughlin (2002a). Pagurus pitagsaleei is very similar to P. boriaustraliensis, and in fact, it had initially been provisionally identified with P. boriaustraliensis by Rahayu & Komai (2000). The differences of these two species have been discussed at length by Rahayu & Komai (2000) and McLaughlin (2002a)., Published as part of Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, pp. 329-363 in Raffles Bulletin of Zoology 70 on page 353, DOI: 10.26107/RBZ-2022-0017, http://zenodo.org/record/7174641, {"references":["McLaughlin PA (2002 a) A review of the hermit crab (Decapoda: Anomura: Paguridea) fauna of southern Thailand, with particular emphasis on the Andaman Sea, and descriptions of three new species. In: Bruce N, Berggren M & Bussawarit S (eds.) Proceedings of the International Workshop on the Crustacea in the Andaman Sea, Phuket Marine Biological Center 29 November - 20 December, 1998. Phuket Marine Biological Center Special Publication, 23 (2): 385 - 460.","Rahayu DL & Komai T (2000) Shallow-water hermit crabs (Crustacea: Decapoda: Anomura: Diogenidae and Paguridae) of Phuket, Thailand. Phuket Marine Biology Center Research Bulletin, 63: 21 - 44.","Morgan GJ (1990) A collection of Thalassinidea, Anomura and Brachyura (Crustacea: Decapoda) from the Kimberley region of northwestern Australia. Zoologische Verhandelingen, 265: 1 - 90."]}

Pagurus tenuilineatus, new species (Figs. 12, 13, 14D) Material examined. Holotype, male 4.2 mm (ZRC 2021.0254), st. IT81, Sister Island, 01°12.789′N 103°50.187′E, rocky reef, intertidal, 26 May 2013. Paratypes, 1 male, 4.2 mm (ZRC 2021.0255), st. IT65, Terumbu Semakau, 01°12.649′N 103°46.199′E, sandy, rocky submerged reef, 24 May 2013; 3 males, 2.8 mm, 3.2 mm, 4.2 mm, 2 ovigerous females, 3.5 mm, 4.2 mm (ZRC 2021.0256), st. IT93, Pulau Jong, 1°12.901′N 103°47.194′E, intertidal, 28 May 2013; 2 ovigerous females, 2.2 mm, 2.5 mm, 1 female, 2.2 mm, 4 males, 1.8–2.7 mm (MZB Cru 5226), st. SD177, Kusu Island, 01°13.314′N 103°51.640′E, dive, 16.4 m, 4 June 2013; 10 males, 2.4–3.3 mm (ZRC 2021.0257), st. SD150, Kusu Island, 01°13.274′N 103°51.659′E, dive, 10.7 m, 1 June 2013. Other material. 3 males, 2 females, 16 specimens in shell (MZB Cru 5227), st. TB91, 01°12.561′N 103°51.322′E, 46.1–72 m, 27 May 2013; 1 female (sl 1.6 mm), no locality, SS2689; 1 male, 1.3 mm (ZRC 2021.0258), st. DR128, 01°12.889′N 103°52.460′E, 75.3−85.7 m, rocky bottom, 30 May 2013; 3 males, 1.3–1.8 mm (ZRC 2021.0259), st. DR161; 2 males, 1.8 mm, 2.2 mm, 2 females, 2.5 mm, 2.9 mm (ZRC 2021.0260), st. SD145, Pulau Hantu, 01°13.514′N 103°44.784′E, dive, 11.7 m, 1 June 2013; 2 males, 2.4 mm, 3.3 mm (ZRC 2021.0261), st. SD150, Kusu Island, 01°13.274′N 103°51.659′E, dive, 10.7 m, 1 June 2013; 1 male, 2.0 mm (MZB Cru 5228), st. DW58, east of Pulau Tekong, 01°25.064′N 104°04.992′E, 10.9–11.3 m, 22 October 2012. Description. Shield (Fig. 12A) approximately as long as broad; anterior margins between rostrum and lateral projections gently concave; anterolateral margins sloping; posterior margin truncate; dorsal surface slightly convex transversely, with longitudinal row of tufts of moderately long setae on either side of midline; paragastric grooves faint. Rostrum obtusely triangular, exceeding as far as lateral projections. Lateral projections broadly triangular, with small marginal spine. Posterior carapace (not figured), measured along midline, distinctly shorter than shield; carapace lateral lobe moderately narrow, not calcified; cardiac sulci parallel, barely reaching to midlength of posterior carapace. Ocular peduncle (including cornea) (Fig. 12A) relatively long, about 0.9 times as long as shield; slightly inflated basally; cornea slightly dilated, diameter about 0.2 times peduncular length; dorsal surface with longitudinal row of tufts of moderately short setae. Ocular acicles narrowly subtriangular, separated basally by width of less than one acicle, with minute marginal spine distally. Interocular lobe partially overhung by rostrum, medially concave. Antennular peduncle (Fig. 12A), when fully extended, slightly overreaching distal corneal margin. Ultimate segment about 1.5 times as long as penultimate segment, slightly widened distally in lateral view. Basal segment with distolateral margin produced in sharply pointed lobe; statocyst lobe weakly inflated, with small spine medially; ventromesial distal angle not produced. Antennal peduncle (Fig. 12A) overreaching distal corneal margins by 0.3 length of fifth segment. Fifth segment with few setae laterally. Fourth and third segments unarmed, with several tufts of long stiff setae mesially. Second segment with dorsolateral distal angle not reaching midlength of fourth segment, with 3 to 5 spinules distomesially; dorsomesial distal angle with small spine; mesial and lateral faces with short to long stiff setae. First segment with subterminal spinule on lateral face. Antennal acicle not reaching base of cornea, gently arcuate, terminating in small spine obscured by long stiff setae; dorsomesial margin with several tufts of long stiff setae. Antennal flagellum about 4 times as long as shield; each article with 1 or 2 minute setae on distal margin. Mouthparts not dissected. Third maxilliped moderately slender; dactyl slightly shorter than propodus; carpus, merus unarmed; ischium with crista dentata consisting of narrowly spaced, moderately large, subacute corneous teeth, and with 1 moderately strong accessory tooth; basis-ischium fusion incomplete; basis with 2 or 3 denticles on mesial margin; exopod reaching distal margin of merus. Chelipeds unequal. Right cheliped larger but not necessarily longer than left (Fig. 13A, B, D, E); chela about 2 times as long as greatest width at base of dactyl, generally suboval in outline in dorsal view. Dactyl subequal in length to palm and slightly overlapped by fixed finger; dorsal surface with sparse, short setae and prominent median row of broad-based, closely set spines; dorsomesial margin with double row of closely set, moderately large spines, decreasing in size distally; space between dorsal midline and dorsomesial margin smooth; ventral surface with scattered tufts of moderately short stiff setae; cutting edge with row of broad calcareous teeth and adjacent row of tufts of stiff setae, terminating in large calcareous claw. Palm slightly shorter than carpus; dorsomesial margin delimited by single row of moderately large, stout spines (Fig. 13A, D); dorsal surface convex, with numerous, small, scattered tubercles and tuft of short setae; dorsolateral margin delimited by small spines extending onto fixed finger, decreasing in size distally; fixed finger dorsal surface slightly depressed and with scattered tubercles, cutting edge with row of moderately large calcareous teeth, terminating in large calcareous claw; mesial face with scattered, very low, minute to small protuberances and sparse very short setae; lateral surface with scattered tufts of short stiff setae; ventral surface gently convex, with scattered tufts of short and long setae. Carpus slightly shorter than merus; dorsodistal margin with row of small spines, dorsomesial margin delimited by row of large spines accompanied by tufts of long stiff setae, dorsal surface with tufts of short to long stiff setae; dorsolateral margin delimited by row of small tubercles obscured by long setae; lateral face nearly glabrous except for some tufts of setae; mesial face (Fig. 13B, E) with few sparse long setae, ventromesial margin produced into flattened, wing-like crest in both sexes (Fig. 13A, D), edge of crest unarmed or with small tubercles in female (Fig. 13D); ventral surface with few tufts of setae. Merus with 1 prominent spine on dorsodistal margin; dorsal surface glabrous; lateral surface nearly glabrous except for few tufts of short setae, ventromesial margin produced in flattened, wing-like crest in males, edge of crest with tiny tubercles distally, strong spine proximally (Fig. 13B), in females no wing-like crest developed, but with row of spines and one prominent spine proximally (Fig. 13E); ventral surface with some low, blister-like protuberances and tufts of moderately long setae. Ischium with tufts of short setae on all surfaces. Left cheliped (Fig. 13C, F) slenderer than right, moderately compressed laterally. Chela elongate subovate in dorsal view, 3.2 times longer than greatest width at base of dactyl. Dactyl about 2.7 times as long as palm, nearly straight with ventrally curved tip; dorsomesial margin with double row of strong spines on proximal 0.7, distal 0.3 smooth; dorsomesial margin and surfaces with tufts of long setae; cutting edge with row of minute, subacute calcareous denticles in proximal 0.4 and row of minute, closely set corneous teeth in distal 0.6, terminating in small corneous claw. Palm about half length of carpus; dorsomesial margin with row of spines, dorsal surface with double row of spines adjacent to dorsomesial margin, extending onto articulation with dactyl, remaining surface with scattered small tubercles; dorsolateral margin with row of spines extending onto tip of fixed finger; fixed finger dorsal surface with longitudinal row of moderately large spines extending along cutting edge, remaining dorsal surface with scattered tubercles; cutting edge bearing row of minute calcareous denticles terminating in moderately large corneous claw; moderately broad hiatus between dactyl and fixed finger. All surfaces with tufts of long setae. Carpus subequal in length to merus; dorsodistal margin with several strong spines; dorsomesial margin with row of moderately large spines; dorsal surface with few tubercles and sparse setae; dorsolateral margin with row of small spines and tufts of short setae; mesial and lateral surface with tufts of short and long setae; ventrolateral margin with row of small spines. Merus with prominent spine on dorsodistal margin; dorsal surface with sparse short stiff setae; lateral and mesial surfaces nearly glabrous except for row of tufts of stiff setae adjacent to dorsal margin and few similar tufts near ventral margin; ventrolateral margin with row of slender, sharp spines and long stiff setae; ventromesial margin with row spines, 2 larger spines proximally. Female left cheliped same as male. P2 and P3 (Fig. 12B, C) stout, right P2 slightly overreaching tip of extended right cheliped. Dactyls 0.9‒1.0 times as long as propodi, 4.3–4.6 times longer than broad, in dorsal view nearly straight, in lateral view slightly curving ventrally; dorsal and ventral margins each with row of tufts of short to moderately long setae, ventral margins each with row of 5‒6 moderately large corneous spines increasing in size distally. Propodi slightly narrowing distally; dorsal surfaces unarmed but with row of long stiff setae; lateral and mesial surfaces with few tufts of long stiff setae; ventral surfaces with few tufts of long stiff setae. Carpi each with small dorsodistal spine; with row of tufts of long stiff setae on dorsal margin; lateral surface convex, with row of tufts of long stiff setae along midline. Meri each with row of tufts of long stiff setae on dorsal surface; lateral surface almost smooth, with few tufts of long stiff setae distally; ventral surface unarmed but with row of tufts of short to long stiff setae, ventrodistal lateral margin unarmed. Ischia unarmed but with tufts of setae on dorsal and ventral margins. P4 semichelate, left (Fig. 12D) slightly larger than right (Fig. 12E). Dactyls slightly curved ventrally, terminating in small corneous claw; each with row of minute, closely spaced corneous teeth on ventral margin; no preungual process. Propodal rasp consisting of 1 row of corneous scales. All segments with dorsal and/or ventral tufts of long stiff setae. Anterior lobe of sternite of third pereopod (Fig. 12F) subrectangular, ventral surface with tufts of setae medially. Male with 3 unequally uniramous pleopods. Female second to fifth pleopods greatly unequally biramous with much elongate exopods; length third> second> fourth> fifth. Telson (Fig. 12G) with distinct lateral indentations; posterior lobes strongly produced, rounded, unequal, median cleft shallow; each terminal margin with row of numerous slender spines interspersed by spinules, not extending onto lateral margin. Colour in life. Shield mottled with light brown and white, with dark brown patches on anterolateral and dorsodistal surface. Ocular peduncle whitish proximally; narrow brown ring at base of cornea and broad brown patch proximally; cornea dark brown. Antennular peduncle generally blue, distal part of penultimate segment and flagella orange. Antennal peduncle generally white; second and fourth segments each with three dark brown longitudinal stripes on dorsal surface, fifth segment with dark brown stripe on lateral and mesial margin; flagellum with brown stripe along lateral and mesial margin of each article, white on articulation of each segment. Right cheliped mottled with light brown and white in general, with large dark brown patches and stripes; mesial surfaces of carpus and merus with irregular patterns of dark brown on white background. Left cheliped with thin brown lines on white background on chela, carpus, and merus. Ambulatory legs with thin dark brown stripes on propodi, carpi, meri, and ischia; dactyls each with one dark brown median stripe and two broad light brown bands (one subdistal and one proximal); propodi, carpi, and meri each with three dark brown stripes on lateral surface, with broad light brown band medially. Dark brown stripes on chelipeds and ambulatory legs usually reaching ends of segments (Fig. 14E). Distribution. At present known only from Singapore; 0–85 m, on reef, sandy and rocky bottom. Etymology. The name is derived from Latin tenuis, meaning slender, and linea, meaning stripes, alluding to the narrow stripes on the chelipeds and pereopods, used as a noun in apposition. Remarks. The characters of this new species correspond with the Pagurus anachoretus group as defined by Forest & Ngoc-Ho (1992) and McLaughlin & Forest (1999). Among the species in this group, P. tenuilineatus, new species, belongs to the group which have wing-like projection on mesial face of the carpus and merus of the right cheliped, i.e., P. boriaustraliensis, P. gordonae (Forest, 1956b), P. hedleyi, P. kulkarnii, P. liochele (Barnard, 1947), P. pitagsaleei, and P. sticticus McLaughlin, 2007b. The presence of a row of moderately large spines on the dorsal surface of the fixed finger of the left cheliped, extending along cutting edge but not reaching the distal part of the finger, separates this new species from its congeners. Furthermore, differences between congeners are also observed on the proportion of the dactyl and palm of the left cheliped. In P. tenuilineatus, new species, the dactyl of the left cheliped (2.7 times as long as palm) is much longer than that of P. boriaustraliensis and P. pitagsaleei (1.5 times as long as palm), P. gordonae (almost as long as palm), P. liochele (1.3–2 times as long as palm), P. kulkarnii (2.5 times as long as palm), and P. sticticus (1.8 times as long as palm), whereas in P. hedleyi the left cheliped has a much longer dactyl (3.3 times as long as palm). Although living colouration of the species in the anachoretus group is quite specific, with colour pattern usually consisting of patches and longitudinal stripes of pigment that cover part or all of the segment of the chelipeds and ambulatory legs (McLaughlin & Forest, 1999), the position and colour pigmentation of the stripes and patches are different from one species to another. The colouration for P. hedleyi, P. kulkarnii, P. pitagsaleei, and P. tenuilineatus has been described above and differences can be seen in Fig. 14. Forest (1956b) described the colour of P. gordonae as follows: shield, ocular and atennal peduncles are greenish grey with brown longitudinal patches, antennnular peduncle with large brown band on penultimate segment, ultimate segment brown on distal half; antennal flagella alternately brown and white; chelipeds greenish brown, carpi and meri with irregular longitudinal stripes; ambulatory legs with irregular brown stripes on half proximal of each segment, half distal orange without any stripes. McLaughlin & Forest (1999: 322) cited the colour of P. liochele after Barnard (1950) as follows: ocular peduncle sienna at base, distal half cobalt, with narrow dark sienna ring immediately adjacent to black cornea, meral segment of left and right chelipeds with cobalt band border with sienna, and distal margin dark sienna; granules on dorsal surface of palm white on pale sienna ground, sienna longitudinal stripes on dactyl and fixed finger; proximal halves of meral segment of second and third pereopods sienna, distal halves pale, longitudinal sienna stripes on carpi and dactyls and dorsally on proximal halves of propodi, distal halves of propodi yellowish, passing into cobalt apically. Pagurus boriaustraliensis shield is cream or pale brown with dark brown mottling, ocular peduncle cream with black or reddish black short longitudinal stripes distally and proximally, chelipeds cream brownish with dark brown line, ambulatory legs with longitudinal brown stripes, and with brown band around midline (Morgan, 1990). The colouration in life of P. sticticus is not known, but in preservative the ambulatory legs have orange spots and patches on each segment (McLaughlin, 2007b)., Published as part of Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, pp. 329-363 in Raffles Bulletin of Zoology 70 on pages 353-357, DOI: 10.26107/RBZ-2022-0017, http://zenodo.org/record/7174641, {"references":["Forest J & Ngoc-Ho N (1992) Description de Pagurus dartevellei (Forest, 1958) (Crustacea, Decapoda, Paguridae). Bulletin du Mueum national d'Histoire naturelle, Series 4, 14 (A): 217 - 227.","McLaughlin PA & Forest J (1999) Hermit crabs of the genus Pagurus Fabricius (Crustacea, Decapoda, Paguridae) from South-eastern South Africa. Annals of the South African Museum, 105 (7): 297 - 344.","Forest J (1956 b) Sur une collection de Paguridae de la Cote de l'Or. Proceedings of the Zoological Society of London, 126: 335 - 367.","Barnard KH (1947) Description of new species of South African decapod crustacea, with notes on synonymy and new records. Annals and Magazine of Natural History, Series 11, 13: 361 - 392.","McLaughlin PA (2007 b) Hermit crabs (Crustacea: Anomura: Paguroidea) of the Dampier Archipelago, Western Australia. Records of the Western Australian Museum, Supplement No. 73: 273 - 288.","Barnard KH (1950) Descriptive catalogue of South African Decapod Crustacean (crabs and shrimps). Annals of the South African Museum, 38: 1 - 837.","Morgan GJ (1990) A collection of Thalassinidea, Anomura and Brachyura (Crustacea: Decapoda) from the Kimberley region of northwestern Australia. Zoologische Verhandelingen, 265: 1 - 90."]}

Pagurus hedleyi (Grant & McCulloch, 1906) (Fig. 14A) Eupagurus kirkii Miers, 1884: 267, pl. 28, fig. C (name preoccupied by Eupagurus kirkii Filhol, 1883; type locality: Arafura Sea). Eupagurus hedleyi Grant & McCulloch, 1906: 37 (type locality: Arafura Sea; replacement name for Eupagurus kirkii Miers, 1884). Pagurus hedleyi; Haig & Ball, 1988: 185, fig. 13. Pagurus kulkarnii: Morgan, 1987b: 182; Morgan, 1990: 27 (not Pagurus kulkarnii Sankoli, 1962). Material examined. 1 male, 3.8 mm (ZRC 2021.0241), SEA3607, Outside Punggol jetty, 1°25.360′N 103°54.201′E, 11.3 m, sandy mud, 16 January 2014; 1 female, 4.0 mm (ZRC 2021.0242), SEA7151, 1°21.908′N 103°38.628′E, 11 m, gravel, mud, 9 April 2014; 1 male, 3.6 mm (ZRC 2021.0243), SEA5992, Between Tekong East and Pengarang, 01°23.914′N 104°05.353′E, 10.6–10.7 m, sandy, broken shell, 25 March 2014; 1 male, 2.7 mm, 1 ovigerous female, 2.9 mm (ZRC 2021.0244), SEA4280, 1°19.911′N 103°37.657′E, 7.5–7.7 m, sandy mud, fine shell, 11 February 2014; 3 males, 3.1–3.5 mm, 3 ovigerous females, 2.7–3.8 mm (ZRC 2021.0245), st. Beting Bornok, coll. H. Wong, 28 October 2015; 1 male, 3.1 mm, 1 female, 3.6 mm (ZRC 2021.0246), st. SD150, Kusu Island, 10.7 m, 1 June 2013; 1 male, 3.8 mm, st. IT80, Terumbu Bemban, rocky reef, 26 May 2013; 2 males, 4.2–4.4 mm (ZRC 2021.0247), st. IT86, Cyrene Reef, 1°15.374′N 103°44.816′E, 23 May 2013; 2 males, 1.6–2.7 mm (ZRC 2021.0248), Lazarus Island, 20 May 2011; 1 male, 1.6 mm (ZRC 2021.0249), st. DR91, 01°12.561′N 103°51.322′E, 46–72 m, 27 May 2013; 1 male, 3.3 mm (ZRC 2021.0250), st. SD84, southwest Tekukor, 01°13.800′N 103°50.250′E, 8 m, 27 May 2013. Colour in life. Shield mottled with cream and light brown. Ocular peduncles white proximally, narrower white band distally just proximal to corneas, broad blue band medially flanked by similar broad, orange band subproximally and subdistally; corneas grey. Antennular peduncle penultimate segment transparent blue proximally, orange distally; ultimate segment blue; flagella bright orange. Antennal peduncle and antennal acicle generally white with dark brown or black stripes. Chelipeds palm and dactyl cream with short, black or light brown stripes or blotches, spines white; carpus and merus bluish white with large black stripes and blotches. P2 and P3 generally pinkish white; dactyls with short black or dark brown stripes proximally, light brown blotch distally, propodi, carpi, and meri each with short black or dark brown stripes and faint shade of bluish band medially (Fig. 14A). Distribution. Arafura Sea, Torres Strait, coast of Queensland, Singapore; 5–72 m, on sandy mud, gravel and fine shell fragment substrates. Remarks. Haig & Ball (1988) illustrated the holotype and a specimen from Arafura Sea, and the specimens in this study agree well with their morphological discussion. Among the species of Pagurus having a wing-like projection or lobe on the mesial face of the carpus and merus of the right cheliped, P. hedleyi is most similar to P. kulkarnii in having broad longitudinal stripes on the pereopods. When alive, these two species are easily distinguished from each other by their colouration as follows: in P. kulkarnii the shield has a large dark brown blotch on the dorsal surface, and the ocular peduncle is white with a large brown blotch proximally and narrow brown band just proximal to the cornea (Fig. 14B); in P. hedleyi, the dorsal surface of the shield is mottled with white and light brown, the ocular peduncle is white proximally and distally, with a broad blue ring medially flanked by similary broad, orange bands subproximally and subdistally (Fig. 14A). Both species have dark brown or black broad stripes on the P2 and P3 that do not reach the distal and proximal ends of each segment, but these stripes are shorter in P. hedleyi and broader in P. kulkarnii. With regard to mophological characters, as stated by McLaughlin (2002a), the presence of one or two irregular rows of strong spines on the dorsal surface and dorsomesial margin of the dactyl of the right cheliped in P. hedleyi, in contrast to scattered low tubercles in P. kulkarnii, separates these two species., Published as part of Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, pp. 329-363 in Raffles Bulletin of Zoology 70 on page 352, DOI: 10.26107/RBZ-2022-0017, http://zenodo.org/record/7174641, {"references":["Grant FE & McCulloch AR (1906) On a collection of Crustacea from the Port Curtis district, Queensland. Proceedings of the Linnean Society of New South Wales, 1906: 1 - 53.","Miers EJ (1884) Crustacea. In: Report on the zoological collections made in the Indo-Pacific Ocean during the voyage of H. M. S. \" Alert \" 1881 - 2. British Museum, London, pp. 178 - 322, 513 - 575.","Filhol H (1883) Note sur quelques especes nouvelles d' Eupagurus recueillies en Nouvelle-Zelande. Bulletin de la Societe Philomathique de Paris, Series 7, 8: 66 - 68.","Haig J & Ball EE (1988) Hermit crabs from northern Australian and eastern Indonesian waters (Crustacea Decapoda: Anomura: Paguroidea) collected during the 1975 Alpha Helix Expedition. Records of the Australian Museum, 40: 151 - 196.","Morgan GJ (1987 b) Hermit crabs (Decapoda, Anomura: Coenobitidae, Diogenidae, Paguridae) of Darwin and Port Essington, Northern Australia. The Beagle: Records of the Museums and Art Galleries of the Northern Territory, 4: 165 - 186.","Morgan GJ (1990) A collection of Thalassinidea, Anomura and Brachyura (Crustacea: Decapoda) from the Kimberley region of northwestern Australia. Zoologische Verhandelingen, 265: 1 - 90.","Sankoli KN (1962) On a new species of hermit crab Pagurus kulkarnii sp. nov. (Anomura: Paguridae). Journal of Zoological Society of India, 13: 136 - 142.","McLaughlin PA (2002 a) A review of the hermit crab (Decapoda: Anomura: Paguridea) fauna of southern Thailand, with particular emphasis on the Andaman Sea, and descriptions of three new species. In: Bruce N, Berggren M & Bussawarit S (eds.) Proceedings of the International Workshop on the Crustacea in the Andaman Sea, Phuket Marine Biological Center 29 November - 20 December, 1998. Phuket Marine Biological Center Special Publication, 23 (2): 385 - 460."]}

Rahayu, Dwi Listyo (2022): Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species. Raffles Bulletin of Zoology 70: 329-363, DOI: 10.26107/RBZ-2022-0017

Osawa, Masayuki, Ota, Yuzo (2020): New Records of Species of Gebiidea and Anomura (Crustacea: Decapoda) from the Sea of Japan. Species Diversity 25: 295-307, DOI: 10.12782/specdiv.25.295

The common hermit crab Pagurus bernhardus (Linnaeus, 1758) is an abundant and ecologically important benthic crustacean in the northeastern Atlantic Ocean. While this species has been intensively studied in terms of its ecology, physiology, behavior, and larval development, knowledge about its population structure and demographic history is still lacking. We examined, for the first time, the genetic variability of P. bernhardus by analyzing two mitochondrial gene fragments (CO1 and 16S) from more than 150 specimens collected from various locations from the Iberian Peninsula to Norway. Our results provide evidence for a significant genetic structure according to the sampled regions for both genetic markers. Furthermore, a comprehensive demographic history reconstruction, mainly based on neutrality tests and a Bayesian Skyline Plot (CO1), revealed a recent demographic expansion of P. bernhardus that preceded the Last Glacial Maximum. Such pattern of retrieved demographic trend could have been likely a successive process to historical contraction of the species into potential climate refugia within the surveyed geographic spectrum.

Komai, Tomoyuki, Miller, Allison K., Malay, Maria Celia D. (2022): Three new species of pagurid hermit crabs (Decapoda: Anomura: Paguroidea) from the Northern Mariana Islands, Micronesia. Zootaxa 5099 (5): 563-585, DOI: https://doi.org/10.11646/zootaxa.5099.5.4

Nematopagurus marianicus n. sp. (Figs. 5–8, 12B) Material examined. Holotype. SIO-BIC C14523, male (sl 2.8 mm), Agrihan, no depth record, 17 June 2015, crab traps, field No. S 25722.4. Paratypes. SIO-BIC C14238, 1 male (sl 2.9 mm), same data as holotype, field No. S 25722.2; SIO-BIC C14512, 1 male (sl 1.9 mm), station AKM-PAG-04, Pagan, 18.0865°N, 145.7652°E, 58–89 m, 20 June 2015, crab traps, field No. S 25713.1; SIO-BIC C14513, 2 males (sl 2.3, 2.3 mm; including DNA voucher), 2 ovigerous females (sl 2.1, 2.6 mm), same data as holotype; SIO-BIC C14517, 1 ovigerous female (sl 2.3 mm), Guguan, station AKM-GUG-05, 17.2912°N, 145.8371°E, 40–44 m, 23 June 2015, Buoy Guam (a kind of ring net), field No. S 25750.4; SIO-BIC C14518, 1 male (sl 2.8 mm), Guguan, station AKM-GUG-03, 17.6093°N, 145.8101°E, 48–84 m, 22 June 2015, crab traps, field No. S 25745.2; SIO-BIC C14519, 1 ovigerous female (sl 2.1 mm), same data as SIO-BIC C14518, field No. S 25745.3; SIO-BIC C14520, 3 males (sl 2.2, 2.5, 2.8 mm), 1 female (sl 1.9 mm), same data as SIO-BIC C14518, field No. S 25745.4; SIO-BIC C14522, 1 immature male (sl 1.7 mm), Pagan, 18.01°N, 145.04°E, 20 June 2015, ring nets for trapping crabs, field No. S25717; SIO-BIC C14524, 1 male (sl 2.3 mm), Pagan, depth not recorded, 17 June 2015, crab traps, field No. S 25722.3. Description. Gills biserial, 11 pairs. Shield (Fig. 5A) approximately as long as wide, dorsal surface with longitudinal row of setae posterior to anterolateral projection on either side; anterior margin between rostral lobe and lateral projections weakly interrupted. Rostrum as broadly triangular or rounded rostral lobe, not quite reaching to level of lateral projections, unarmed, but with tuft of short setae on either side of midline. Lateral projections obtusely triangular, with or without submarginal spine. Lateral carapace lobe moderately broad. Ocular peduncles (Fig. 5A) relatively stout, 0.8 length of shield, subcylindrical; dorsal surface tufts of short setae at corneal indentation; mesial surface with small, low setose protuberance proximal to corneal base; cornea substantially dilated, corneal width about half of peduncular length. Ocular acicles narrowly triangular, terminally bunt and with submarginal spine, separated widely. Interocular lobe fully exposed. Antennular peduncles (Fig. 5A) slightly overreaching distal corneal margin by tip of ultimate article. Ultimate article without tuft of setae at distolateral margin, dorsal surface almost glabrous. Penultimate article unarmed. Basal article without spine laterally on statocyst lobe, ventrodistal angle not particularly produced. Antennal peduncles (Fig. 5A) falling slightly short of distal corneal margin. Articles 3–5 unarmed but each with few tufts or individual stiff setae. Article 2 with dorsolateral distal angle produced beyond proximal margin of article 4, terminating in small spine and sometimes with additional subterminal spine, mesial and/or lateral margins with few tufts of setae; dorsomesial distal angle with small spine. Article 1 with ventrolateral margin prominently produced, unarmed. Antennal acicles reaching to or beyond midlength of peduncular article 5, terminating in small spine; dorsomesial margin with several tufts of stiff setae proximally and row of stiff setae in distal half. Antennal flagella long, far overreaching outstretched chelipeds; each article with one or two minute bristle-like setae, at least in distal half. Maxilliped 3 (Fig. 5B, C) endopod moderately slender. Carpus and merus unarmed. Ischium with well-developed crista dentata consisting of row of closely set, corneous-tipped teeth and with 1 well-developed accessory tooth located subdistally. Exopod reaching midlength of carpus. Right cheliped (Fig. 6A–D) larger and slightly longer than left. Chela subovate in general outline, 2.2 times as long as wide. Dactylus 0.8 length of palm, bearing row of small spines on dorsomesial margin, not extending to tip; mesial face with several tufts of short to long simple setae and few spinules proximally. Palm subequal in length to carpus, with dorsomesial and dorsolateral marginal row of small spines, latter extending onto proximal half of fixed finger; dorsal surface with very weak median row of small spines, distinct as row only proximally, and with additional numerous small spines or spinules and short, distally curved setae, spines extending onto proximal half of fixed finger; mesial and lateral faces each with sparse tufts of simple setae, longer and more numerous on mesial and ventral faces; occlusal margin of fixed finger with row of 5 obtuse calcareous teeth and minute, fused corneous teeth in distal 0.2, terminating in small corneous claw. Carpus slightly widened distally, 1.8 times as long as distal width, with row of moderately large spines on dorsomesial margin and row of smaller spines on dorsal surface laterally, dorsodistal margin with 1 small spine; mesial and lateral faces each with numerous tufts of long simple setae, partially obscuring faces; ventrolateral distal margin armed with 1 small spine, ventromesial distal margin unarmed; gently convex ventral surface with scattered long setae. Merus dorsal surface with subdistal transverse ridge but otherwise smooth, almost glabrous; dorsodistal margin with 1 small spine mesially, obscured by row of moderately long setae; lateral surface with few, short transverse rows of minute setae, ventrolateral margin with 2 widely spaced spines in distal 0.3; mesial surface almost glabrous except for few tufts of short setae, ventromesial margin with 3 or 4 spines accompanied by few long setae; ventral surface with short, setose transverse ridges. Ischium unarmed. Left cheliped (Fig. 7A–D) moderately slender, reaching level of base of dactylus of right cheliped. Chela elongate subovate in general outline, 2.6 times as long as wide. Dactylus with row of small spines on dorsomesial margin in proximal half. Dorsomesial and dorsolateral margins of palm each with row of spines, dorsal surface slightly elevated in midline and with row of moderately small spines, additional small spines and short setae scattered on dorsal surface, and median longitudinal row of spinules extending onto fixed finger; mesial and lateral faces each with few sparse tufts of short to long simple setae. Carpus with row of small spines on dorsomesial and dorsolateral margins, dorsodistal margin with 1 small median spine; lateral and mesial faces with sparse tufts or short vertical rows of long simple setae, partially obscuring faces (particularly on dorsal half of lateral face); ventral surface with few low protuberances and sparse tufts of long setae. Merus with transverse row of numerous setae on dorsodistal margin; dorsal surface glabrous; lateral face almost glabrous except for few tufts of setae adjacent to ventral margin, ventrolateral margin with 4 or 5 spines (distalmost one strongest); mesial face also almost glabrous with few tufts of short setae, ventromesial margin with 3 or 4 small spines accompanied with tufts of setae; ventral surface with short, setose transverse ridges. Ischium unarmed. Pereopods 2 and 3 (Fig. 8A–D) generally similar in armature and ornamentation, third slightly longer. Dactyli slender (length 13 times of width in second, 14 times of width in third), 1.3 times as long as propodus in second, 1.8 in third; dorsal and ventral margins each with row of sparse setae, which are easily broken off; lateral faces with few short setae; mesial faces each with dorsal (arranged in single or double row, 14–20 in number) and ventral rows (arranged in single row, 6–10 in number) of moderately spaced small, slender corneous spines (Fig. 8B, D). Propodi 1.4–1.8 lengths of carpi; rounded dorsal surfaces each with row of sparse short, stiff setae; lateral and mesial faces smooth, glabrous; ventral surfaces glabrous, with 1 or 2 small corneous spines at ventrodistal margin (Fig. 8B, D). Carpi slightly more than 0.5 length of meri; dorsal surfaces each with dorsodistal and dorsoproximal spines and row of stiff setae; lateral, mesial and ventral faces almost glabrous. Meri each with dorsal row of tufts of setae (fewer in third), ventrolateral distal angle with small spine (second) or unarmed; ventral margins each with few small spines (second) or unarmed (third). Ischia each with few tufts of setae on dorsal and/or ventral surfaces. Pereopods 4 semichelate (Fig. 5D); dactylus gently curved, terminating in long corneous claw, ventral margin with row of minute corneous spinules; propodal rasps each consisting of single row of corneous scales. Pereopods 5 weakly semichelate. Male with elongate, soft sexual tube extruded from gonopore of right coxa (Fig. 5E); left with gonopore, but not protruded (Fig. 5E). Sternite 6 anterior lobe (Fig. 5F) subcircular, anterior margin with row of short to moderately long setae. Sternite 8 (Fig. 1E) with pair of circular protuberances. Pleon dextrally twisted. Male with unpaired left pleopods 3–5, pleopods 3 and 4 greatly unequally biramous, pleopod 5 uniramous. Female with paired and modified first pleopods typical of genus; unpaired left pleopods 2–5 unequally biramous. Telson (Fig. 5G, I) divided into anterior and posterior portions by distinct lateral indentations; posterior lobes slightly asymmetrical, separated by moderately deep median cleft; terminal margins each with 2–6 principal spines and sometimes with additional spinules laterally. Colouration in life. Fig. 12B. Shield generally pink; posterior carapace darker reddish. Ocular peduncles red, with dark ring basally; cornea brown-gray. Antennular and antennal peduncles red, antennal flagellum uniformly reddish translucent. Right chela mottled with red and pink, distal parts of fingers whitish; carpus with red and pink longitudinal stripes; merus also with alternate red and pink longitudinal stripes. Left cheliped similarly coloured to right cheliped. Ambulatory dactyli pink to violet, subdistally with red ring, distally white; propodi, carpi and meri with alternate red and pink longitudinal stripes (4 red stripes visible on respective article). Pereopods 4 and 5 also reddish. Pleon reddish, semi-translucent. Variation. The setation on chelipeds in the small, immature male specimen (sl 1.7 mm; SIO-BIC C14522) is sparse compared with adult specimens, suggesting that the setation becomes denser with growth. Spination on the terminal margins of the telson is also variable, as figured (Fig. 5G, I). Housing. Gastropod shells. Etymology. Derived from the locality where the type specimens of the new species were collected. Distribution. Presently known only from the Northern Mariana Islands, at depths of 40– 89 m. Remarks. McLaughlin (2004b) reviewed species of Nematopagurus, recognizing 26 species, including five new species. Since then two new species have been described in the genus (McLaughlin & Okuno 2010; Lima et al. 2019). Of the 28 presently recognized species, 26 occur in the Indo-West Pacific: N. longicornis A. Milne-Edwards & Bouvier, 1892 is restricted to the eastern Atlantic, and N. micheleae Lima, Tavares & de Mendonça, 2019 is known only from Trindade Island, off Espirito Santo, Brazil, southwestern Atlantic. Nematopagurus marianicus n.sp. resembles N.gardineri Alcock, 1905 (junior synonyms: N.holthuisi McLaughlin & Hogarth, 1998; N. pilosus Komai, 1999) and N. lewinsohni Türkay, 1986. Shared characters are: dactylus of right cheliped armed with several spines on dorsal surface; dorsal surfaces of palms of chelae armed with generally even covering of pointed spines over entire surface, but devoid of drop-like sensory structures. Nematopagurus marianicus n. sp. is distinguished from N. gardineri by the following particulars: the cornea is distinctly dilated, of which the width is about half of the ocular peduncle length in N. marianicus n. sp. (Fig. 5A), whereas it is not particularly dilated, of which the width is 0.3–0.4 in N. gardineri (cf. McLaughlin 2004b: fig. 23a); the carpus of the left cheliped bears a dense covering of long iridescent setae on the upper part of the lateral face in N. marianicus n. sp. (Fig. 7B, D), while there is no such setal field on the left cheliped carpus in N. gardineri (cf. McLaughlin 2004b: fig. 23b, c; see also Komai 1999: figs. 16E, 18E, as N. pilosus); and the dactyli of the pereopods 2 and 3 are more elongate and slender in N. marianicus than in N. gardineri (Fig. 8A–D versus McLaughlin 2004b: fig. 23d, e). Nematopagurus marianicus n. sp. is easily differentiated from N. lewinsohni by the lack of a row of bristlelike setae on the dorsal surface of each ambulatory dactylus (Fig. 8A–D), which is present in the latter species (McLaughlin 2004b: fig. 22c). The carpus of the left cheliped lacks a dense setal field on the lateral face in N. lewinsohni (cf. McLaughlin 2004b: 210, fig. 22b), which is present in N. marianicus n. sp., as mentioned above.

Pagurixus eminens n. sp. (Figs. 9–13) Material examined. Holotype: SIO-BIC C14515, male (sl 1.7 mm), Guguan, station AKM-GUG-02, 17.3063°N, 145.8317°E, 0–5 m, 22 June 2015, snorkel, coll. A.K. Miller, field No. S 25737.4. Paratypes. SIO-BIC C14258, 1 female (sl 1.8 mm), Sarigan, station AKM-SAR-01, 16.6977°N, 145.7727°E, 0–5 m, 24 June 2015, crab trap, coll. A.K. Miller, field No. S 25762.3; SIO-BIC C14516, 1 female (sl 1.8 mm), Agrihan, 18.45°N, 145.38°E, depth not recorded, 17 June 2015, crab trap, coll. A.K. Miller, field No. S 25684.5, DNA voucher. Description. Gills biserial, 11 pairs. Shield (Fig. 9A) 1.1 times as long as wide; anterior margin between rostrum and lateral projections gently concave; anterolateral margins sloping; dorsal surface slightly convex, with few tufts of short setae anterolaterally. Rostrum triangular, moderately produced, terminating acutely. Lateral projections obsolete, each with submarginal spinule. Ocular peduncles (Fig. 9A) moderately long and stout, 0.7 length of shield, with few tufts of short stiff setae on dorsal surface mesially; cornea not dilated, corneal diameter about 0.3 of peduncular length; basal part not inflated, as wide as cornea. Ocular acicles subtriangular, each with submarginal spinule. Antennular peduncles (Fig. 9A–C) stout, reaching distal corneal margin by tip of ultimate segment. Ultimate article 1.8 times longer than high, with prominent tuft of long setae on dorsolateral distal portion; ventral surface with 2 rows of short setae directed outward. Basal article with small laterodistal spine on statocyst lobe. Ventral flagellum with row of dense long setae directed outwards on lateral and mesial margins. Antennal peduncles (Fig. 9A) reaching distal corneal margin by tip of article 5. Article 3 with small spine at ventromesial distal angle (not visible in dorsal view). Article 2 with spinule at dorsomesial distal angle; laterodistal projection short, falling far short of midlength of article 4, terminating in small spine. Article 1 with laterodistal spinule; ventromesial distal margin with small projection. Antennal acicles moderately long, slightly arcuate, reaching nearly to base of cornea, terminating in spine; mesial and lateral margins with sparse setae. Antennal flagella not reaching extended right cheliped; each article with few short setae on distal margin. Maxilliped 3 (Fig. 9D) endopod moderately stout. Ischium with well-developed crista dentata consisting of row of minute corneous-tipped teeth and 1 accessory tooth. Merus and carpus unarmed. Exopod reaching midlength of carpus. Male right cheliped (Fig. 10A–D) stout, not particularly elongate. Chela suboval, 1.5 times as long as wide. Dactylus subequal in length to palm measured along mesial margin, terminating in small corneous claw; dorsomesial or mesial margin not delimited; slightly rounded dorsal surface without conspicuous spines or tubercles, mesial surface slightly granular, ventral surface nearly smooth; cutting edge with 2 obtuse calcareous teeth in proximal 0.6 and row of minute, corneous teeth in distal 0.4. Palm not widened distally, slightly wider than long, 0.8 times as long as carpus; dorsal surface convex, slightly granular, no conspicuous spines or tubercles, with scattered sparse very short setae; dorsolateral and dorsomesial margins not delimited; lateral and mesial faces almost glabrous; ventral surface also smooth, gently convex, with few short setae. Fixed finger terminating in corneous claw; cutting edge irregularly dentate. Carpus subequal in length to merus, widened distally, length about 1.4 of distal width; dorsal surface sparsely granulate, only with few scattered short to moderately short setae, but without conspicuous spines; dorsodistal margin with few spinulose tubercles; lateral surface without trace of division, with coarse granules, ventrolateral margin with 1 small blunt tubercle distally; mesial face also with coarse granules, ventromesial margin faintly granulate; ventral surface convex, with few short setae. Meral-carpal articulation lacking any pronounced clockwise rotation. Merus unarmed on dorsodistal margin, dorsal surface also unarmed and glabrous; lateral and mesial faces also smooth, glabrous; ventrolateral margin armed with row of 3 small spines in distal 0.4; ventromesial margin faintly tuberculate; ventral surface gently convex, with sparse long setae. Ischium with smooth ventromesial margin; surfaces smooth, with few setae. Female right cheliped (Fig. 11A–D) distinctly longer and stouter than left, proportionally more slender than male right cheliped. Chela subovate in dorsal view, 1.8 times longer than broad. Dactylus 1.2 times as long as palm, terminating in small corneous claw; dorsomesial margin not delimited; dorsal surface with nearly smooth; mesial face with tufts of short setae; ventral surface nearly smooth, with sparse short to long setae; occlusal margin with row of small corneous teeth. Palm about half-length of carpus; convex dorsal surface almost glabrous; dorsolateral margin delimited by distinct, granular ridge extending to midlength of fixed finger; dorsomesial margin not delimited; lateral face with sparse coarse granules; mesial face with few granules, ventral face convex, almost smooth, with few setae. Fixed finger terminating in small corneous claw; occlusal margin with few small calcareous teeth proximally and row of small corneous teeth in distal half. Carpus, merus and ischium generally similar to those of male right cheliped in armature; carpus length 1.6 times of width. Merus generally similar to that of male. Left cheliped (Fig. 10E–H) moderately short, stout, distinctly shorter than right. Chela subovate in outline, approximately twice as long as wide, 1.1 times longer than carpus. Dactylus 1.3 times as long as palm, terminating in small corneous claw, with sparse tufts of short setae on surfaces; dorsal surface rounded, unarmed; occlusal margin with row of small corneous teeth increasing in length distally. Palm about half-length of carpus; dorsal surface with few granules; dorsolateral and dorsomesial margins not delimited; lateral surface with few short setae; mesial and ventral surfaces smooth; scattered long setae on ventral surface (including fixed finger). Fixed finger terminating in small corneous claw, occlusal margin with row of small corneous teeth. Carpus somewhat compressed laterally, slightly shorter than merus; length about twice of distal width and 1.7 of height; dorsolateral margin not delimited, dorsomesial margin with row of small spines or tubercles and bristle-like stiff setae; dorsodistal margin with small spine medially; lateral surface nearly perpendicular, without trace of division, bearing sparse granules, ventrolateral distal margin denticulate; mesial surface nearly smooth, ventromesial distal margin unarmed; ventral surface convex, with sparse long setae. Merus glabrous on dorsal surface, dorsodistal margin unarmed; lateral face almost smooth, ventrolateral margin with row of 3 small spines in distal 0.3; mesial face also smooth, ventromesial margin faintly tuberculate; ventral surface slightly with sparse long setae. Ischium unarmed. Ambulatory legs (Fig. 11E–H) relatively stout, similar on right and left. Dactyli 0.8–0.9 times as long as propodi, 4.4–5.1 times longer than wide, terminating in large corneous claws; dorsal surfaces with few short setae; lateral and mesial faces glabrous, latter unarmed (Fig. 11F, H); ventral margins each with 5 moderately long corneous spines increasing in size distally. Propodi not tapering distally, 2.9–3.1 times longer than wide; dorsal surfaces with sparse moderately long setae; lateral and mesial faces smooth, glabrous; ventral margins each with 3–4 corneous spinules, ventrodistal margins each with single or paired small corneous spines. Carpi each with small dorsodistal spine, dorsal surfaces unarmed, with row of moderately long setae; lateral, mesial, and ventral faces glabrous. Meri with sparse setae on dorsal margins; lateral and mesial faces glabrous; ventrolateral distal margins unarmed, ventral margins spinulose (second) or slightly angular (third). Ischia with few (second) or row (third) of setae on dorsal margin; ventral margins with few setae. Females with unpaired gonopore on left coxa of pereopod 3. Pereopods 4 (Fig. 9E) weakly semichelate, generally similar from right to left, although right slightly smaller. Dactylus moderately broad, straight, terminating in small corneous claw, with few short setae. Propodus with few setae on dorsal margin; mesial faces nearly flat or slightly convex, with few short setae, but without prominent tuft of setae; propodal rasp of single row of corneous scales. Carpus with several setae on dorsal margin. Pereopods 5 chelate. Coxae of male (Fig. 9F) strongly unequal; right coxa with prominent ventromesial protrusion directed mesially and bearing prominent tuft of setae oriented mesially and exceeding well beyond lateral margin of left coxa; left coxa with gonopore anteriorly encircled by short to long setae, no protrusion of vas deferens seen. Anterior lobe of thoracic sternite 6 (Fig. 9G) subrectangular, with row of sparse short setae on anterior margin. Thoracic sternite 8 (Fig. 9F) composed of two subequal, moderately separated, rounded lobes; each lobe bearing few short setae laterally to anteriorly. Pleon without distinctive features; male with unpaired left pleopods 3–5; female with unpaired left pleopods 2–4. Telson (Fig. 9H) with weak lateral indentation; posterior lobes rounded, terminal margins unarmed. Colouration in life. Fig. 13. Shield pale brown generally, with pair of darker spots posterior to bases of ocular acicles; posterior carapace yellowish translucent. Ocular peduncles also pale brown, with large darker blotch on dorsal surfaces. Antennular peduncle ultimate article brown, becoming paler proximally. Antennal peduncle article 2 dark brown; article 3 and 4 each with dark brown blotches on dorsal surface; article 5 with lateral and mesial margins brown, otherwise semi-translucent; flagella banded with white and brown (brown bands wider than white bands). Right cheliped chela and carpus dark brown on dorsal surface, merus distally dark brown in distal half, yellowish brown in proximal half. Left cheliped fingers yellowish white, palm dark brown on dorsal face; carpus and merus distally yellowish white and proximally dark brown. Pereopods 2 and 3 generally yellowish white with dark brown markings (see also Fig. 11G); dactyli each with proximal ring; propodi each with middle ring; carpi yellowish white in distal 0.3, dark brown proximally in proximal 0.7; meri each with middle ring. Pleon entirely yellowish semi-translucent. Distribution. Presently known only from the Northern Mariana Islands (Guguan, Sarigan and Agrihan), intertidal to shallow subtidal (5 m). Etymology. From the Latin “eminens” (= prominent), in reference to the prominent ventromesial protrusion on the right coxa in males of the new species. Remarks. Pagurixus is currently represented by 41 species, all of which are distributed in the Indo-West Pacific (McLaughlin & Haig 1984; Komai & Osawa 2006; Komai 2010; Komai & Poupin 2013; Osawa et al. 2013; Komai et al. 2021). Most species occur in tropical or subtropical coral reefs, while some species are restricted to the temperate areas of Australia and New Zealand (McLaughlin & Haig 1984; Gunn & Morgan 1992; Morgan 1993; de Saint Laurent & McLaughlin 2000; Komai & Osawa 2006; Komai 2010). The genus is informally divided into two species groups, viz., P. anceps Forest, 1954 and P. boninensis (Melin, 1939), based on the presence (P. boninensis group) or absence (P. anceps group) of setal rows on the ventral surface of the antennular peduncle ultimate article (McLaughlin & Haig 1984; Komai & Osawa 2006). Pagurixus eminens n. sp. is referred to the subgroup B of the Pagurixus boninensis group, as diagnosed by Komai & Osawa (2006), because of the lack of a longitudinal ridge on the lateral surface of the left cheliped carpus. It is very similar to P. annulus Komai & Poupin, 2013, presently known only from Europa Island in the Mozambique Strait, western Indian Ocean, in the morphology and the banded colour pattern of the chelipeds and ambulatory legs (Komai & Poupin 2013). Pagurixus eminens n. sp. is distinguished from P. annulus by the possession of a prominent mesial protrusion on the coxa of the right pereopod 5 in the males and better developed tuft of setae arising from the distal margin of that protrusion; setae consisting the tuft are long, far overreaching lateral margin of the left coxa (Fig. 9F). In P. annulus, the right coxa of the pereopod 5 in the males is devoid of a mesial protrusion; setae on the right coxa are short and fewer, not reaching the left coxa (Komai & Poupin 2013: fig. 2J). Another potential diagnostic character is the armature of the telson terminal margin. In P. eminens n. sp., the terminal margins of the telson are unarmed (Fig. 9H), rather than having a row of spinules on each terminal margin as in P. annulus (cf. Komai & Poupin 2013: fig. 2K). The colour pattern of the chelipeds and ambulatory legs are generally similar between the two species, but details are still different. In P. eminens n. sp., the carpus of the left cheliped is dark brown in the dorsal surface; the dark brown bands on the carpi of the ambulatory legs extend to the proximal margins on the dorsal surfaces (Fig. 13). In contrast, in P. annulus, the carpus of the right cheliped is clearly bi-coloured with the distal half white and proximal half darkly coloured; the bands on the carpi of the ambulatory legs are medial, not extending to the proximal end of the article (Komai & Poupin 2013: figs. 1B, 2C). In addition, it is remarkable that there are not specimens referable to either P. annulus or P. eminens n. sp. in intervening localities despite the recent active collections (cf. Komai 2010; Osawa et al. 2013; Komai & Rahayu 2013; Komai et al. 2021). Pagurixus brachydactylus Komai & Osawa, 2006, presently known only from the Ogasawara Islands, Japan and P. pseliophorus Komai & Osawa, 2006, known from the Japanese mainland and the Ryukyu Islands, are also similar to P. eminens n. sp., particularly in the absence of dorsomesial spines on the male right cheliped carpus and the relatively short dactyli of the pereopods 2 and 3. The colour pattern of the chelipeds and ambulatory legs are also similar among the three species, in particular, P. pseliophorus and P. eminens n. sp. are very similar to one another in this regard. Pagurixus brachydactylus differs from the present new species in the lack of a ventromesial protrusion on the right coxa of the pereopod 5 in the male (cf. Komai & Osawa 2006: fig. 26M). The male cheliped palm and carpus are more coarsely granular in P. brachydactylus than in P. eminens n. sp. (Komai & Osawa 2006: fig. 27A–C versus Fig. 10A–D). The pereopods 4 exhibit sexual dimorphism in the size and setation in P. brachydactylus; in males, the pereopods 4 is subequal in the size and similar from right to left, whereas in females, they are unequal and dissimilar in the setation (Komai & Osawa 2006: fig. 26D–K). In P. eminens n. sp., the pereopods 4 are not sexually dimorphic; subequal and similar in the setation. The dactylus of the left pereopod 3 is distinctly shorter than the propodus in P. brachydactylus (cf. Komai & Osawa 2006: fig. 28B), rather than subequal in length to the latter article in P. eminens n. sp. (Fig. 11D). Pagurixus pseliophorus is distinguished from P. eminens n. sp. by the following particulars. The shield is relatively narrower in P. pseliophorus than in P. eminens n. sp. (1.2–1.3 times as long as wide versus 1.0–1.1 times as long) (Komai & Osawa 2006: fig. 36A versus Fig. 9A). The palm of the male right cheliped is subequal in the length to the carpus in P. pseliophorus (cf. Komai & Osawa 2006: fig. 37A–D), whereas it is shorter than the latter in P. eminens n. sp. (Fig. 10A–D). The dactyli of the pereopods 2 and 3 are distinctly shorter than the propodi and relatively stout in P. pseliophorus (cf. Komai & Osawa 2006: 39), rather than subequal in the length to the latter article and relatively slender in P. eminens n. sp. (Fig. 11E–H). It should be noted that the known range of the new species is not far from the Southern Mariana Islands, where the paguroid fauna is relatively well documented (Paulay et al. 2003; Malay et al. 2021).

Catapagurus tenuilamina n. sp. (Figs. 1–4, 12A) Material examined. Holotype. SIO-BIC C14512, male (sl 2.7 mm), off Pagan Island, Northern Mariana Islands, station crab trap, 18.0865N, 145.7652E, 58–89 m, 19 June 2015, field no. S25713.2, DNA voucher. Description. Gills biserial, 11 pairs. Shield (Fig. 1A) approximately as long as broad; anterior margin between rostral lobe and lateral projections concave; anterolateral margins sloping, continuing to convex lateral margin; posterior margin roundly truncate; dorsal surface polished, with longitudinal rows of tufts of short setae posterior to lateral projections; carapace lateral lobes moderately narrow, well calcified. Rostral lobe rounded, not reaching lateral projections. Lateral projections broadly triangular, each with terminal, submarginal spine. Posterior carapace 0.6 length of shield; posterolateral plates moderately wide anteriorly, drawn out into relatively thin bands reaching to posterior margins, posterior median plate short, only weakly calcified. Ocular peduncles (Fig. 1A) 0.7 times as long as shield, widened distally, constricted proximal to base of corneas; corneal width 0.4 of peduncular length. Ocular acicles narrow, spike-like, reaching 0.3 length of ocular peduncles, terminating acutely; widely separated basally. Interocular lobe clearly visible in dorsal view. Antennular peduncles (Fig. 1A) overreaching distal corneal margin by full length of ultimate article and 0.2 of penultimate article. Ultimate article 0.5 times as long as shield, 5 times as long as distal height, with tuft of 3 moderately long setae at dorsodistal lateral angle; dorsal surface glabrous. Penultimate article almost glabrous. Basal article with slightly produced, acute ventrodistal margin; statocyst lobe weakly inflated in proximal half of article. Antennal peduncles (Fig. 1A, B) overreaching distal corneal margin by 0.3 length of article 5. Articles 5 and 4 with few setae. Article 3 with few setae on unarmed ventromesial distal angle. Article 2 with produced, spiniform dorsolateral distal angle falling far short of midlength of article 4; dorsomesial distal angle with small spine. Article 1 with small spine at dorsolateral distal angle. Antennal acicle reaching distal end of article 4 and overreaching corneal base, terminating in spine. Flagella broken off and not preserved. Maxilliped 3 (Fig. 1C, D) with endopod moderately slender; merus with small dorsodistal spine; ischium with crista dentata consisting of 5 small, well spaced teeth; accessory tooth small, subdistal in position. Right cheliped (Fig. 2A–D) long, moderately stout for genus. Chela elongate subovate in dorsal view, 2.7 times as long as wide. Dactylus 0.6 length of palm, with moderately long to long setae on every surface, terminating in blunt calcareous claw; dorsal surface slightly convex transversely, without spines or tubercles; dorsomesial margin not delimited; mesial and ventral faces also smooth; occlusal margin with 2 obtuse calcareous teeth, slightly overlapped by fixed finger. Palm shorter than carpus, 1.8 times as long as wide; dorsomesial and dorsolateral margins not delimited, gently convex dorsal surface covered with minute granules extending onto lateral surface, and with few setae near base of fingers; mesial faces smooth ventrally; ventral surface gently convex, with scattered short to moderately long setae; fixed finger terminating in blunt calcareous claw, with sparse tufts or individual setae on every surface, occlusal margin with obtuse calcareous tooth at midlength, entire margin minutely denticulate. Carpus subequal in length to merus, widened distally, 2.6 times as long as distal width; dorsomesial and dorsolateral margins each delimited with row of tiny spines or tubercles, strongest distally, and with few short setae; dorsolateral margin more strongly elevated than dorsomesial margin; dorsal surface with scattered granules; lateral surface with scattered granules, ventromesial distal angle with 2 spinules; mesial surface with row of granules adjacent to dorsal margin and scattered granules distally, ventromesial distal angle with short row of 4 tubercles; ventral surface gently convex, smooth. Merus subtriangular in cross section; dorsodistal margin with conspicuous spine; dorsal surface with few subdistal transverse ridges followed by row of evenly spaced setae; lateral surface with sparse granules in distal half, ventrolateral margin minutely granulated, with 1 distal spine; mesial surface granular ventrally, otherwise almost smooth, ventromesial margin with 1 triangular spine at distal angle, otherwise minutely granulated; ventral surface with sparse granules and few short setae. Ischium with 1 small spine on granulate ventral surface, other surfaces smooth. Coxa (Fig. 1E) armed with small spine on ventromesial angle. Left cheliped (Fig. 3A–D) slender, about 0.9 length of right cheliped. Chela 4.8 times as long as wide; fingers nearly straight in lateral view. Dactylus 1.3 times as long as palm, distally curved in dorsal view, terminating in small corneous claw; surfaces almost smooth, with sparse setae; dorsomesial margin not delimited; occlusal margin with row of minute corneous teeth over almost entire length. Palm 0.5 length of carpus, 4.7 times as long as wide; dorsomesial and dorsolateral margins not delimited, transversely convex dorsal surface with faintly granulate; ventral surface slightly convex, smooth; fixed finger with sparse short setae, terminating in small corneous claw; occlusal margin with row of minute corneous teeth over entire length. Carpus subequal in length to merus; dorsomesial and dorsolateral margins delimited with row of spinules or granules (increasing in size and acuteness distally), dorsal surface with scattered coarse granules; lateral surface coarsely granulate in upper half, almost smooth in lower half, distoventral margin spineless; mesial surface nearly smooth except for granules adjacent to dorsal margin; ventral surface smooth, distoventral margin also spineless. Merus dorsodistal margin with 1 small spine; dorsal surface with row of several setae; lateral surface with sparse granules, particularly on ventral part, nearly straight ventrolateral margin with 1 small spine distally; mesial surface almost smooth except for granulate ventral part, nearly straight ventromesial margin with 1 small distal spine; ventral surface coarsely granulate. Ischium with 1 small subdistal spine on ventrolateral margin; ventral surface minutely granulate, other surfaces smooth. Coxa (Fig. 1E) with small spine on ventromesial angle. Pereopods 2 (Fig. 4A, B) slender, overreaching tips of outstretched chelipeds. Dactyli narrowly blade-shaped (length 11.5 times of width), subequal in length to propodi; in dorsal view, straight; in lateral view, slightly curved ventrally; dorsal margin and ventral margins unarmed; mesial faces concave, each with row of 23 moderately spaced, spiniform setae adjacent to dorsal margin, row of 20 minute spiniform setae adjacent to ventral margin; lateral surfaces with sparse short setae in distal half (Fig. 4B). Propodi slightly more than twice length of carpi, slightly narrowing distally in lateral view; dorsal and ventral margins smooth, former with 1 minute spiniform seta located at distal 0.25; lateral and mesial surfaces smooth; ventral margins each with row of few, widely spaced minute spiniform setae. Carpi short, about half-length of meri; dorsal surfaces minutely granulate, with 1 small dorsodistal spine; otherwise almost smooth. Meri each with 1 small dorsodistal spine and 2 unequal subdistal spines (proximal one largest), dorsal surface otherwise almost smooth, with row of evenly spaced moderately long setae; lateral and mesial surfaces smooth except for minutely granulate ventral parts; ventral surfaces minutely granulate, ventrolateral distal angle with tiny spine. Ischia unarmed. Right pereopod 3 (Fig. 4C, D) generally similar to pereopods 2 in general setation and armature, but slightly longer. Dactylus narrowly blade-shaped (length 13.8 of width), 1.1 times as long as propodi; mesial faces concave, with row of 23 spiniform setae, increasing in length distally, adjacent to dorsal margin, and with row of 20 minute spiniform setae adjacent to ventral margin; lateral surface with sparse short setae on distal part (Fig. 4D). Propodus about twice length of carpi; dorsal margins with 2 widely spaced, minute spiniform setae (one at distal 0.25 and other at about mid-length) and 1 minute spiniform setae distomesially; ventral margins with 2 minute spiniform setae subdistally. Carpus about half-length of merus; dorsal surfaces minutely granular, with 1 small dorsodistal spine. Merus with small dorsodistal spine and 2 evenly spaced subdistal spines; ventrolateral distal margin with 1 small spine. Ischium longer than those of pereopods 2, unarmed, ventral margin gently concave. Left pereopod 3 broken off, not preserved. Pereopods 4 (Fig. 1F) weakly semichelate; dactyli each with well developed preungual process far extending well beyond tip of corneous claw; propodal rasp consisting of single row of corneous scales on distal 0.8 of ventral margin. Pereopods 5 chelate. Males with long right sexual tube (right coxa; Fig. 1G, H) curved dorsally over pleon and overreaching pleonal midline, terminus simple, glabrous. Left coxa (Fig. 1G) without gonopore, with longitudinal row of short setae on ventral surface laterally. Thoracic sternite 6 (Fig.1I) anterior lobe broadly rounded, faintly bi-lobate, much shorter than large posterior lobe. Sternite 8 (pereopods 5) (Fig. 1G) consisting of two small lobes separated by shallow median groove, each with small tubercles anteriorly. Pleon with small, uniramous unpaired left pleopods 3 and 4, no pleopod 5. Uropodal protopods not protruding posteriorly. Telson (Fig. 1J) with lateral indentations suggesting separation of anterior and posterior portions; posterior lobes separated by moderately deep U-shaped median cleft, each terminating in subacute tip; lateral margins rounded, not converging posteriorly, with few short setae; longitudinal terminal margins unarmed. Colouration in life. Fig. 12A. Body and appendages generally brown. Cornea brown-gray. Chelipeds ventral surface paler; meri dark tinge on lateral and mesial faces. Ambulatory leg dactyli semi-transparent, each with brown median stripe and row of brown spots dorsally; propodi each with 3 longitudinal stripes on pale brown background; carpi each with tinge of white on lateral surface; meri mottled with dark and light brown. Distribution. Presently known only from off Pagan Island, Northern Mariana Islands, at depth of 58– 89 m. Etymology. From the combination of the Latin words, tenuis (= slender) and lamina (= blade), in reference to the slender but blade-shaped dactyli of the pereopods 2 and 3 of the new species. Used as a noun in apposition. Remarks. Catapagurus was heretofore represented by 25 species worldwide, of which 22 species are known from the Indo-West Pacific region (Asakura 2001; McLaughlin 2004a; McLaughlin et al. 2010; Komai & Rahayu 2021). The genus is divided into two informal species groups on the basis of the shape of the ambulatory dactyli, viz., the C. ensifer Henderson, 1893 group and C. misakiensis (Terao, 1914) species group (cf. Asakura 2001; Komai & Takeda 2006; Nucci & Melo 2012; Komai & Rahayu 2021). Catapagurus tenuilamina n. sp. is referred to the C. ensifer group because of the blade-shaped dactyli of the pereopods 2 and 3. The following 11 species are referred to the C. ensifer species group: C. albatrossae (Asakura, 2001), C. alcocki McLaughlin, in Hogarth et al., 1998, C. ensifer, C. granulatus Edmondson, 1951, C. haigae (Asakura, 2001), C. insolitus Komai & Osawa, 2009, C. kosugei (Asakura, 2001), C. latus Komai & Rahayu, 2021, C. lewinsohni (Asakura, 2001), C. sharreri A. Milne-Edwards, 1880, and C. tuberculosus (Asakura, 1999). Among these species, Catapagurus tenuilamina n. sp. is morphologically most similar to C. granulatus in the elongate ocular acicles, the possession of a ventromesial distal spine on each coxa of cheliped, and the relatively slender ambulatory dactyli, compared with typical members of the group such as C. ensifer, C. haigae (Asakura 2001), and C. latus Komai & Rahayu, 2021, and the general configuration of the telson. Nevertheless, the new species differs from C. granulatus in the following minor particulars: the ultimate article of the antennular peduncle is much more slender in C. tenuilamina n. sp. than in C. granulatus (Fig. 1A, B versus Asakura 2001: fig. 19B); the occlusal margin of the right cheliped fixed finger is armed with one obtuse calcareous tooth at the middle and otherwise minutely denticulate in C. tenuilamina n. sp. (Fig. 2C), whereas it is armed with a row of several calcareous teeth of various size in C. granulatus (Asakura 2001: fig. 29C); the dactylus of the pereopod 3 is more slender in the new species than in C. granulatus (Fig. 4C, D versus Asakura 2001: fig. 36B); the merus of the pereopod 2 is armed with 2 subdistal dorsal spines in C. tenuilamina n. sp. (Fig. 4A), rather than only 1 subdistal spine in C. granulatus (Asakura 2001: fig. 40D); and the telson posterior lobes are devoid of a terminal spine in the new species (Fig. 1J), rather than armed with a distinct corneous spine terminally in C. granulatus (cf. Asakura 2001: Fig. 44B). Catapagurus granulatus is presently known only from Hawaii, of which endemism to the area is suggested.