A revision of “blanket-hermit crabs” of the genus Paguropsis Henderson, 1888, with the description of a new genus and five new species (Crustacea, Anomura, Diogenidae)

Rafael Lemaitre; Dwi Listyo Rahayu; Tomoyuki Komai

doi:10.3897/zookeys.752.23712

Research Article

A revision of “blanket-hermit crabs” of the genus Paguropsis Henderson, 1888, with the description of a new genus and five new species (Crustacea, Anomura, Diogenidae)

Rafael Lemaitre^‡, Dwi Listyo Rahayu^§, Tomoyuki Komai^|

‡ National Museum of Natural History, Smithsonian Institution, Washington D.C., United States of America

§ Indonesian Institute of Sciences, Lombok, Indonesia

| Natural History Museum and Institute, Chiba, Japan

Corresponding author: Rafael Lemaitre ( lemaitrr@si.edu )

Academic editor: Sammy De Grave

This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Citation: Lemaitre R, Rahayu DL, Komai T (2018) A revision of “blanket-hermit crabs” of the genus Paguropsis Henderson, 1888, with the description of a new genus and five new species (Crustacea, Anomura, Diogenidae). ZooKeys 752: 17-97. https://doi.org/10.3897/zookeys.752.23712

ZooBank: urn:lsid:zoobank.org:pub:CCE50CBC-D7DC-44C0-B7A9-57F829813A83

Abstract

For 130 years the diogenid genus Paguropsis Henderson, 1888 was considered monotypic for an unusual species, P. typica Henderson, 1888, described from the Philippines and seldom reported since. Although scantly studied, this species is known to live in striking symbiosis with a colonial sea anemone that the hermit can stretch back and forth like a blanket over its cephalic shield and part of cephalothoracic appendages, and thus the common name “blanket-crab”. During a study of paguroid collections obtained during recent French-sponsored biodiversity campaigns in the Indo-West Pacific, numerous specimens assignable to Paguropsis were encountered. Analysis and comparison with types and other historical specimens deposited in various museums revealed the existence of five undescribed species. Discovery of these new species, together with the observation of anatomical characters previously undocumented or poorly described, including coloration, required a revision of the genus Paguropsis. The name Chlaenopagurus andersoni Alcock & McArdle, 1901, considered by Alcock (1905) a junior synonym of P. typica, proved to be a valid species and is resurrected as P. andersoni (Alcock, 1899). In two of the new species, the shape of the gills, length/width of exopod of maxilliped 3, width and shape of sternite XI (of pereopods 3), and armature of the dactyls and fixed fingers of the chelate pereopods 4, were found to be characters so markedly different from P. typica and other species discovered that a new genus for them, Paguropsina gen. n., is justified. As result, the genus Paguropsis is found to contain five species: P. typica, P. andersoni, P. confusa sp. n., P. gigas sp. n., and P. lacinia sp. n. Herein, Paguropsina gen. n., is proposed and diagnosed for two new species, P. pistillata gen. et sp. n., and P. inermis gen. et sp. n.; Paguropsis is redefined, P. typica and its previously believed junior synonym, P. andersoni, are redescribed. All species are illustrated, and color photographs provided. Also included are a summary of the biogeography of the two genera and all species; remarks on the significance of the unusual morphology; and remarks on knowledge of the symbiotic anemones used by the species. To complement the morphological descriptions and assist in future population and phylogenetic investigations, molecular data for mitochondrial COI barcode region and partial sequences of 12S and 16S rRNA are reported. A preliminary phylogenetic analysis using molecular data distinctly shows support for the separation of the species into two clades, one with all five species of Paguropsis, and another with the two species Paguropsina gen. n.

Keywords

Diogenidae , hermit crab, new species, Paguropsina gen n. Paguropsis, symbiotic anemone

“In the case of Paguropsis typica the association with a colonial sea-anemone of a genus related to Mamillifera is even more remarkable. Here there is no shell to play the part of “Sir Pandarus of Troy,” but the sea-anemone settles upon the hinder part of the young hermit-crab’s tail, and the two animals grow up together, in such a way that the spreading zoophytes form a blanket which the hermit can either draw completely forwards over its head or throw half-back, as it pleases.”

(Alcock 1905: 7)

Introduction

Two unusual hermit crab specimens collected in the Sibuyan Sea, the Philippines, on board the HMS Challenger Expedition in 1874, were considered so unique by Henderson (1888) that he named a new genus and new species for them, Paguropsis typicus Henderson, 1888 [the spelling of the specific epithet was subsequently corrected by Alcock (1905) to P. typica, for gender agreement]. Henderson found the morphology of the specimens, a male and a female, to be peculiar among hermit crabs, in particular the subdorsal position of pereopods 4 and 5, the presence of unpaired pleopods on the right side rather than on the left, and the membranous pleon bent on itself rather than spirally curved. He was intrigued by the lack of pleonal curvature, and that no trace of habitation or pleonal protection was found with the specimens. Apparently unaware of Henderson’s (1888) taxon, Alcock (1899) described, and Alcock and McArdle (1901) later illustrated, a new genus and species of a hermit crab based on hundreds of specimens collected off southern India, which he named Chlaenopagurus andersoni Alcock, 1899. Alcock also noted various unusual characters such as the puzzling general symmetry, despite the variability of pleopods 3-5 which in his specimens could be present on either the left or right sides in either sex, and devoted considerable discussion to the commensalism he observed. He was able to determine that his species did not use a shell for housing but instead was adapted to live with a colonial sea anemone with a sheet-like coenosarc that the hermit crab tucked under its telson and could stretch over its back like a blanket, thus the common name “blanket-crab” he used in the narratives while on board the “Investigator” expeditions (Alcock 1902). Subsequently, Alcock (1905) considered his taxon to be the same as Henderson’s, and formally placed his C. andersoni as a junior synonym of P. typica.

Paguropsis Henderson, 1888 has remained a monotypic genus since its original description. The single representative of this genus, P. typica, has been presumed to have a broad distribution across the tropical Indo-West-Pacific, from the Philippines, Japan, and Indonesia, to off eastern Africa, where adults have been reported in depths ranging from 110 to 350 m (Henderson 1888, Alcock 1899, Thompson 1943, Kamalaveni 1950, Barnard 1962, Miyake 1982, Baba et al. 1986, Thomas 1989). Paguropsis typica has often been used as an example of a remarkable adaptive specialization and diversity in the Anomura (Stebbing 1893, Boas 1926, Russell 1962, Nicol 1967, Kaestner 1970, Schäfer et al. 1983, McLaughlin 2015) and considerable attention has been given to the curious symbiotic association of this hermit crab with its cnidarian symbiont. However, much confusion exists on the identity of the symbiont as various names and misspellings have been used, such as Epizoanthus paguropsidis or E. paguropsides, by Boas (1926), Schäfer et al. (1983), Ates (2003), and Williams and McDermott (2004); Mammillifera sp. or Mammillifera sp., by Balss (1924, 1927), and Kaestner (1970); Anemonia mammifera, by Nicol (1967); and Actinia equina, by Williams and McDermott (2004). Thus, the true identity of the cnidarian living with P. typica still remains uncertain.

Despite the uniqueness of Paguropsis among the Diogenidae and even Paguroidea as a whole, the morphology of P. typica has not been studied in sufficient detail in light of the modern concept of paguroids. Furthermore, aside from the inclusion of this genus and species in phylogenetic studies related to the origin of lithodids and the phenomenon of carcinization (Richter and Scholtz 1994, McLaughlin and Lemaitre 1997), the evolutionary significance and position of Paguropsis among paguroids has remained unexplored. This knowledge deficiency can be attributed, in part, to the fact that the material of P. typica reported in the literature is scattered in a few museums, with the majority of specimens originally deposited and largely unavailable, in the Indian Museum, Kolkata. The opportunity to examine new material of Paguropsis came when fresh specimens assignable to this genus were found while studying the rich paguroid collections obtained during various collaborative French deep-water faunistic expeditions to the tropical western Pacific. The detailed examination of this new material, and comparison with the types and other previously unreported specimens identified under P. typica and deposited in various museums, revealed that Paguropsis is not monotypic or even monophyletic, and that in addition to P. typica, there are six more species, five of them new to science, all confounded under what was previously believed to be a single species. Altogether, 1042 specimens were examined. Here it is shown that Alcock’s (1899) name P. andersoni needs to be resurrected from the synonymy of P. typica as a valid species. Furthermore, a detailed comparative morphological analysis has shown that two of the five new species discovered, although closely related to P. typica, are morphologically so fundamentally different in characters of the mouthparts, cephalothoracic sternite, chela of pereopods 4, and position of pleopods that they require placement in a new genus, Paguropsina gen. n. Thus, the genus Paguropsis is rediagnosed, and the new genus diagnosed. Both P. typica and P. andersoni are redescribed and illustrated, and all new species fully described and illustrated. Information on coloration is presented for all seven species with newly obtained color photographs. A key to the species of Paguropsis and Paguropsina gen. n. is provided, along with a brief discussion of the biogeography and significance of the morphology of the two genera among the Paguroidea. To assist in future phylogenetic studies, genetic data for each of the seven species is reported for the mitochondrial COI barcode region and partial sequences of 12S and 16S rRNA (Table 1).

Table 1.

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XLSX

List of species, collection site, museum catalog number of vouchers, and GenBank accession numbers for which mitochondrial COI barcode region and partial sequences of 12S and 16S rRNA were obtained in this report.

Species	Locality	Voucher deposition	COI GenBank no.	16S GenBank no.	12S GenBank no.
Paguropsis typica	Philippines	MNHN-IU-2014-9399	MG759674	MG759703	MG773703
	Philippines	MNHN-IU-2014-9427	–	MG759705	–
	Philippines	MNHN-IU-2014-9411	MG759677	MG759704	MG773704
Paguropsis andersoni	Indian Ocean	USNM 42719	–	MG950177	MG950176
Paguropsis andersoni	Madagascar	MNHN-IU-2014-9393	MG759673	MG759692	MG773702
Paguropsis confusa	Philippines	MNHN 50015	MG759683	MG759696	MG773707
	Locality uncertain	MNHN-IU-2014-9420	–	MG759695	MG773705
	Philippines	USNM 1441901	MG759682	MG759694	MG773706
Paguropsis gigas	South China Sea	NTOU A01445	MG759678	MG759697	MG773709
Paguropsis gigas	South China Sea	NTOU A01446	MG759679	MG759698	MG773710
Paguropsis lacinia	Papua New Guinea	MNHN-IU-2013-2288	MG759665	MG759699	MG773711
	New Caledonia	MNHN-IU-2014-9360	MG759666	MG759700	MG773712
	Solomon Islands	MNHN-IU-2014-9367	MG759668	MG759701	MG773713
Paguropsina pistillata	New Caledonia	MNHN-IU-2014-9391	MG759672	MG759689	MG773695
	New Caledonia	MNHN-IU-2014-9401	MG759675	MG759690	MG773696
	New Caledonia	MNHN-IU-2014-9402	MG759676	MG759691	MG773699
Paguropsina inermis	Philippines	MNHN-IU-2014-9372	MG759669	MG759686	MG773700
	New Caledonia	USNM 1441892	MG759681	MG759684	MG773701
	New Caledonia	MNHN-IU-2014-9383	MG759670	MG759687	MG773698
	New Caledonia	MNHN-IU-2014-9362	MG759667	MG759685	MG773697
	South China Sea	NTOU A01447	MG759680	MG759688	MG773693

Materials and methods

Specimens used for this study remain deposited in the following museums: The Natural History Museum, London, UK (formerly British Museum) (BMNH); Natural History Museum and Institute, Chiba, Japan (CBM); Lee Kong Chian Natural History Museum, Zoological Reference Collection of the Raffles Museum of Biodiversity Research, National University of Singapore (LKCNHM ZRC); Muséum national d’Histoire naturelle, Paris, France (MNHN); National Museum of the Philippines, Manila (MNHN); National Taiwan Ocean University, Keelung, Taiwan, ROC (NTOU); National Natuurhistorisch Museum, Naturalis Biodiversity Center, Leiden (formerly Rijksmuseum van Natuurlijke Histoire), the Netherlands (RMNH); Iziko South African Museum, Cape Town, South Africa (SAMC); National Museum of Natural History, Smithsonian Institution, Washington DC USA (USNM); and the Zoological Museum, University of Copenhagen, Denmark (ZMUC).

General morphological terminology follows that of McLaughlin (2003) and Tudge et al. (2012), except for the use of “pleon” instead of “abdomen” used according to Schram and Koenemann (2004). The term “chelipeds” applies to pereopod 1, and “ambulatory legs” to pereopods 2 and 3. Paired pleopods 1 and 2 in males, and paired pleopod 1 in females, are referred to as gonopods. Cephalothoracic somites and their sternites, are numbered I–XIII (five cephalic and eight thoracic), and thoracomeres are I–VIII (three maxillipeds and five pereopods). The measurements indicated for the specimens refer to shield length (SL) in millimeters (mm), measured to the nearest 0.01 from the midpoint of the rostral lobe to the midpoint of the posterior margin of the shield. Miscellaneous abbreviations used are:

CC otter trawl;

CP beam trawl;

DW Warén dredge;

FB fishing boat;

INVMAR Invertébrés Marins (for collections of MNHN);

NO navire océanographique;

ovig ovigerous female(s);

sta station;

RV research vessel;

ROV remotely operated vehicle;

TRV trawling vessel;

USFC United States Fish Commission.

The station data for the following French collaborative campaigns have been obtained from the MNHN website (https://expeditions.mnhn.fr/), published reports (Richer de Forges 1990), or supplied by MNHN staff (P Bouchet, L Corbari, P Martin-Lefèvre, or P Maestrati): BIOPAPUA; BORDAU 1, 2; BATHUS 3; CREVETTIERE; EBISCO; KARUBAR; LITHIST; LUMIWAN; MADEEP; MAINBAZA; MUSORSTOM 1–3, 5, 6; NANHAI; NORFOLK 1, 2; PANGLAO; SALOMON 1, 2; ZHONGSHA. Other expedition or research program abbreviations: DST/NRF ACEP, Department of Science and Technology/National Research Foundation and African Coelacanth Ecosystem Programme or “Spatial Solutions Project”. The original, official format (DDM or DDS) for reporting latitude and longitude for these expeditions has been retained in order to avoid confusion. Months are indicated using the first three letters.

Vouchers, tissue samples, and sequence data of specimens for DNA Barcoding or other genetic analysis were deposited in the MNHN or USNM. All PCR, sequencing, and analytics were carried out at the Laboratories of Analytical Biology at the National Museum of Natural History, Smithsonian Institution. Mitochondrial COI barcode region and partial sequences of 12S and 16S rRNA were obtained by standard protocols (see Evans and Paulay 2012). Unaligned sequences for at least one type specimen of each new species were accessioned to GenBank along with archival data for the respective voucher specimens listed in Table 1. Although this data is included as diagnostic identifiers for the species, and for future phylogenetic studies, a preliminary analysis was performed to generate a tree. Alignments for each locus were obtained using the L-INS-i alignment strategy in MAFFT version 7 (Katoh and Standley 2013). The aligned sequences were concatenated using Sequence Matrix (Vaidya et al. 2011). Phylogenetic analyses were performed on a concatenated dataset (12S + 16S + COI) using Maximum Likelihood (ML) with RAxML (Stamatakis 2006). ML options for RAxML included the GTRCAT model of nucleotide evolution (-m), rapid bootstrap analysis, and search for best-scoring ML tree (-f a), and 1000 bootstrap replicates.

Systematic account

Family Diogenidae Ortmann, 1892

Genus Paguropsis Henderson, 1888

Paguropsis Henderson, 1888: 98 (type species by monotypy: Paguropsis typica Henderson, 1888, gender feminine); Stebbing, 1893: 169; Alcock, 1905: 27; Gordan, 1956: 325; McLaughlin and Lemaitre, 1997: 112 (phylogeny); McLaughlin, 2003: 114 (key); McLaughlin et al., 2010: 23; McLaughlin, 2015: 153, fig. 6.3D.

Chlaenopagurus Alcock, 1899: 113 (type species by monotypy: Chlaenopagurus andersoni Alcock, 1899, gender masculine).

Diagnosis

Thirteen pairs of quadriserial gills [no pleurobranchs on thoracomere VIII (last)], gills consisting of series of twin lamellae each ending on distolateral and distomesial angles in filamentous or stub-like extensions (e.g., Fig. 3A). Shield well calcified, subtriangular or subrectangular; dorsal surface somewhat vaulted; lateral projections broadly triangular, each terminating in small spine. Rostrum prominent and projecting anteriorly, subtriangular, arched and dorsally ridged. Branchiostegite with dorsal margin (e.g., Fig. 2B, D) divided into two calcified plates: one anterodorsal plate poorly delimited ventrally, and one small, subtriangular median plate with distinct central pit. Posterior carapace (e.g., Fig. 2A, C) with well calcified posteromedian plate, and well calcified lateral lobe on each side adjacent to shield. Ocular peduncles short, approx. half as long as shield; corneas dilated (diameter typically half or slightly more than length of ocular peduncle, including cornea); ocular acicles relatively small, subtriangular, armed with small dorsodistal spine. Antennal peduncles distinctly exceeding distal margins of corneas; acicles long, reaching to level of corneas. Mouthparts: maxillule with well-developed and strongly recurved external lobe of endopod; maxilliped 1 with exopodal flagellum, endopodite medially bent at nearly right angle, with distinctly developed epipod; maxilliped 3 ischium with well-developed crista dentata, lacking accessory tooth, exopod slender, 4 or more times as long as broad. Epistome unarmed. Chelipeds symmetrical or nearly so, subequal in size, armed with moderately dense to dense setation and numerous well-spaced small spines or tubercles; coxae each with ventral surface having an uncalcified median longitudinal fissure starting on distal margin and incompletely covering length of ventral surface. Pereopods 2 and 3 long; dactyl of pereopods 3 distinctly longer than dactyl of pereopod 2. Sternite XI (between pereopods 3; e.g., Fig. 5B, D) narrow, separating coxae of pereopods 3 by distinctly less than half length of one coxa (typically 0.2 to 0.3 length of one coxa); anterior lobe flat or slightly concave, posterior lobes broad, arched and forming arrowhead shape with apex directed anteriorly. Pereopod 4 chelate, extending to subdorsal position to manipulate carcinoecium (e.g., Fig. 1A, 2A, C), lacking rasp-like surfaces; dactyl with cutting edge armed with row of small corneous spines; fixed finger with sharp spines on cutting edge arranged like bear claw; coxae (e.g., Fig. 5B, D) with anteroventral margin sharply delimited, keel-like. Sternite XII (between pereopods 4; e.g., Fig. 5B, D) broad, ridge-like, weakly divided medially, with fringe of setae. Pereopod 5 chelate, with weakly-developed propodal rasp. Pleon curling under but not dextrally or sinistrally twisted; pleonal somite 1 not fused to last thoracic somite, with partly calcified tergite and pleura. Male with well-developed paired gonopods 1 and 2, and reduced (uniramous or biramous) pleopod 3–5 on left or right side (occasionally lacking pleopod 5), or altogether lacking pleopods 3–5. Female with paired gonopores; with paired uniramous pleopods 1 modified as gonopods (Fig. 7D); left or right side of pleon with well-developed biramous unpaired pleopods 2–4 (ovigerous) and reduced biramous or uniramous unpaired pleopod 5 (not ovigerous, occasionally absent); brood pouch large (e.g., Figs 1C, 3C), covering pleopods 2–4 and entire egg mass. Uropods and telson symmetrical; exopods long, slender; endopod small, curved. Telson subquadrate or subrectangular, lacking or with obscure lateral indentations; posterior margin weakly divided into broadly rounded lobes.

Distribution

Subtropical to tropical Indo-West Pacific. Depth: 30 to 1125 m.

Habitat and symbionts

Several cnidarian names have been reported in the literature as symbionts of what has been presumed to be P. typica, including: Epizoanthus paguropsidis [e.g., Boas (1926), Schäfer et al. (1983, as E. paguropsides), Ates (2003), Williams and McDermott (2004)]; Mammillifera sp. [e.g., Alcock (1905), Balss (1924, 1927), Ross (1983)]; Actinia equina [e.g., Williams and McDermott (2004)]. There is considerable taxonomic confusion on these cnidarian names. The name E. paguropsidis is considered a nomen nudum apparently introduced by Boas (1926), and attributed to Ates (2003, as per WoRMS Editorial Board 2018). Schäfer et al.’s (1983) study identified the host of the cnidarian as P. typica, but that host is shown herein to actually apply to a species of Parapaguridae. Mammillifera is currently a subjective junior synonym of Zoanthus. Given the discovery of several species previously confounded under P. typica as well several new species, and the general unavailability of hermit crab materials that go along with reports of cnidarian symbionts, it is impossible to ascertain the identity of the cnidarian as well as to which species of Paguropsis or the new genus described herein. Those symbiont names apply to the Zoanthidea (often called Zoantharia), and those associated with hermit crabs that are typically assigned in the literature to colonial species of the genus Epizoanthus, (JD Reimer, pers. comm.; see Fig. 1D). However, the symbionts found with species of Paguropsis are actually indeterminate species of acontiate anemones which belong to the Actiniaria (DG Fautin, pers. comm.), and are herein reported as such.

Type species

Paguropsis typica Henderson, 1888, by monotypy. Gender: feminine.

Species included

In addition to the type species, P. typica, the genus includes: P. andersoni (Alcock, 1899), and three new species described herein.

Remarks

Henderson (1888) considered Paguropsis and its only species at that time, P. typica, to be unique among hermit crabs based on the peculiar subdorsal position of pereopods 4 and 5 adapted to manipulate the symbiont zoanthid, the presence on the left or right side of the pleopods, and the straight pleon. Alcock (1905) considered his monotypic genus Chlaenopagurus Alcock, 1899 to be a junior synonym of Paguropsis, although he provided no explanation for that taxonomic action. Alcock (1905) suggested that Paguropsis was closely related to Paguristes Dana, 1851, but differed in the former having stout eyestalk, a non-coiled pleon, symmetrical tail fan (uropods and telson), chelate pereopod 4, and indifferent position (left or right side) of the pleopods. The taxonomy or morphology of Paguropsis has not been discussed or revised since that early time, although Boas (1926) did study in detail the morphology of P. typica relative to its symbiotic zoanthid.

During this study, several important characters previously overlooked or not sufficiently discussed have been added to the diagnosis of Paguropsis. Among these are the shapes of mouthparts (maxillule external lobe of endopod, and maxilliped 3 exopod); presence on posterior carapace of a well delimited calcified lateral lobe (e.g., Fig. 2A) fused to shield; on the branchiostegite (e.g., Fig. 2B, D), presence of a well calcified median plate with a central pit adjacent to the cervical groove, and an anterodorsal plate; presence on ventral surface of coxae of chelipeds of a longitudinal, uncalcified fissure (e.g., Fig. 5B, D); shape of thoracic sternites XI and XII (between pereopods 3 and 4 respectively; e.g., Fig. 5B, D); development of a full chela lacking rasp on pereopod 4, and distinct, bear-like claw armature of fixed finger; and sharply delimited anteroventral margin of coxae of pereopods 4 (e.g., Fig. 5B, D). Furthermore, coloration has been found to be unique for each of the species (Figs 8, 18A, B, 28A–D).

Paguropsis typica Henderson, 1888

Figs 1A–C, 2A, B, 3, 4, 5A, B, 6, 7, 8A, B, 14A, 28A, Table 1

Paguropsis typicus Henderson, 1888: 99, pl. 10, fig. 4 (type locality: HMS Challengersta 204A or B, off Tablas Island, Philippines); Murray, 1895: 789.

Paguropsis typicus : Pzibram, 1905: 199; Boas, 1926: 1, figs 1, 7, 8–11; Rabaud, 1941: 263; Gordan, 1956: 325 (in part). (See “Remarks”).

Paguropsis typica : Estampador, 1937: 55; Balss, 1924: 775, figs 31, tbl. 2 (see “Remarks”); Balss, 1956: 1429 (in part); Nicol, 1967: 583; Kaestner, 1970: 299; Miyake, 1982: 98, pl. 33, fig. 6 (color photo); Schäfer et al., 1983: figs 12 (in part, see “Remarks”); Ross, 1983: 171; Baba et al., 1986: 192 (fig. 141, color photo), 193 (Japanese text), 299 (English text); Richter and Scholtz, 1994: 189 (phylogeny); Ates, 2003: 42, tbl. 1; Williams and McDermott, 2004: 16, tbl. 1; McLaughlin et al., 2010: 23; McLaughlin, 2015: 152, fig. 6.3D; Malay et al., 2018: 55.

Paguropsis tyica (misspelling): Schäfer et al., 1983, fig. 12 (in part, see “Remarks”)

Not Paguropsis typica: Schäfer et al., 1983: 229, figs 1, 2; Williams and McDermott, 2004: 12, 66, tbl. 1 (= glaucothoë stage of Parapaguridae, see “Remarks”)

Type material

Lectotype (herein selected), male 6.0 mm, Tablas Island, Philippines, HMS Challenger, sta 204A to 204B, 12°43' to 12°46'N, 122°09' to 122°10'E, 182.9–210.3 m, 2 Nov 1874 (BMNH 1888.33). Paralectotype: 1 female 7.1 mm, same data as lectotype (BMNH 1888.33).

Other material

Japan: Intensive Research of Unexploited Fisheries Resource on Continental Slopes, Japan Fisheries Resources Conservation Association, FBShin’ei-maru No. 53, Kita-Koho Seamount, Kyushu-Palau Ridge, 26°46'09"N, 135°20'03"E, 360 m, 17 Nov 1978, trawl: 4 males 10.2–16.4 mm (CBM-ZC 4898); same data, 4 females 10.3–13.2 mm (CBM-ZC 4899).

South China Sea: NANHAI 2014, cruise OR5: staDW 4105, 13°57.8902'N, 115°25.5073'E, 297–565 m, 3 Jan 2014: 1 male 3.6 mm (NTOU A01442). ZHONGSHA 2015, cruise ORI 1113: staCP 4149, 16°06.54'N, 114°20.05'E, 165 m, 26 Jul 2015: 1 male 5.8 mm, 1 female 6.6 mm (NTOU A01443); staCP 4150, 16°06.602'N, 114°21.45'E, 162 m, 26 Jul 2015: 1 male 6.0 mm (NTOU A01444). Hong Kong: Cruise 4/63, sta 66, Transect 56, [no locality, coordinates, depth, or date], coll. Fisheries Research Station: 1 female 5.8 mm (MNHN-IU-2014–9438).

Philippines: USFCAlbatross, Philippines Expedition: Quezon, Luzon Island, Tayabas Bay, Lucena City, sta 5369, 13°48'00"N, 121°43'00"E, 193.8 m, 24 Feb 1909: 1 male 10.7 mm, 1 female 5.7 mm (USNM 1107610); Quezon, Luzon Island, Tayabas Bay, Lucena City, sta 5371, 13°49'40"N, 121°40'15"E, 151.8 m, 24 Feb 1909: 1 male 10.4 mm, 1 female 6.2 (molted, parasitized) (USNM 1107593); Quezon, Luzon Island, Tayabas Bay, Unisan, sta 5375, 13°42'15"N, 121°50'15"E, 195.7 m, 2 Mar 1909: 1 male 12.6 mm (USNM 1107608); Visayan Sea, Leyte Island, Villaba, near Capitancillo Island, sta 5403, 11°10'00"N, 124°17'15"E, 332.8 m, 16 Mar 1909: 1 male 11.0 mm (USNM 1107573); Camotes Sea, Cebu, Camotes Islands, NW of Pacijan Island, sta 5408, 10°40'15"N, 124°15'00"E, 290.8 m, 18 Mar 1909: 2 males 11.8, 12.8 mm, 1 female 11.7 mm, 1 ovig female 11.4 mm (USNM 1107590); Camotes Sea, Cebu, Camotes Islands, W of Pacijan Island, sta 5409, 345.6 m, 18 Mar 1909: 2 males 10.9, 14.6 mm, 1 female 8.5 mm (USNM 1107574); Cebu Island, Bohol Strait, SW of Lauis Point, sta 5411, 265.2 m, 23 Mar 1909: 2 males 8.6 mm, 13.3 mm, 2 females 11.2, 11.9 mm (USNM 1107594); Bohol Strait, Between Bohol and Cebu Islands, sta 5412, 10°09'00"N, 123°52'00"E, 296.3 m, 23 Mar 1909: 1 female 9.1 mm, 3 ovig females 10.9–11.8 mm (USNM 1107599); Cebu Island, Naga, Bohol Strait, sta 5417, 301.7 m, 25 Mar 1909: 4 males 7.9–13.2 mm, 2 females 7.1, 10.0 mm (USNM 1107584); Gulf of Albay, Albay, Luzon Island, E of S Luzon, sta 5454, 13°12'00"N, 123°50'30"E, 279.8 m, 7 Jun 1909: 1 female 7.8 mm (USNM 1107578); northern Mindanao, sta 5519, 8°47'00"N, 123°31'15"E, 332.8 m, 9 Aug 1909: 1 female 6.4 mm (USNM 1107588); Zamboanga del Norte, Mindanao Island, sta 5520, 10 Aug 1909, 186.5 m: 1 female 5.7 mm (USNM 1100423). MUSORSTOM 1, NOVauban: N of Lubang, staCC 12, 14°00'N, 120°17'E, 187–210 m, 20 Mar1976: 1 male 7.0 mm, 3 females 6.4–6.8 mm (USNM 1441983); N of Lubang, staCP 18, 13°57'N, 120°17'E, 150–159 m, 21 Mar 1976: 1 ovig 7.5 mm (MNHN-IU-2014–9374); N of Lubang, staCP 25, 14°02'N, 120°18'E, 191–200 m, 22 Mar 1976: 1 male 10.5 mm (MNHN-IU-2014–9373); N of Lubang, staCP 27, 14°00'N, 120°16'E, 188–192 m, 22 Mar 1976: 22 males 4.6–4.8 mm, 25 females 3.9–9.0 mm (MNHN-IU-2014–9399); NW of Lubang, staCP 54, 13°56'N, 119°58'E, 975–1125 m, 26 Mar 1976: 37 males 5.1–10.4 mm, 26 females 5.5–9.7 mm, 11 ovig females 6.7–8.3 mm (MNHN-IU-2014–9395); N of Lubang, staCP 64, 14°00'N, 120°19'E, 194–195 m, 27 Mar 1976: 16 males 4.2–8.1 mm, 19 females 4.3–6.7 mm, 1 ovig female 7.0 mm (MNHN-IU-2014–9371). MUSORSTOM 2, NOCoriolis: N of Lubang, staCP 01, 14°00'N, 120°18'E, 188–198 m, 20 Nov 1980: 5 males 5.8–11.0 mm, 2 females 6.0, 6.1 mm, 1 ovig female 9.6 mm (MNHN-IU-2014–9425); N of Lubang, staCP 02, 14°00'N, 120°17'E, 184–186 m, 20 Nov 1980: 2 males 7.1, 9.4 mm, 1 female 6.7 mm, 2 ovig females 7.0, 7.8 mm (MNHN-IU-2014–9426), 1 ovig female 8.8 mm (MNHN-IU-2014–9431); between Luçon and Lubang, staCP 06, 13°56'N, 120°22'E, 136–152 m, 20 Nov 1980: 1 female 6.7 mm (MNHN-IU-2014–9432); N of Lubang, staCP 10, 14°01'N, 120°18'E, 188–195 m, 21 Nov 1980: 1 male 5.7 mm (MNHN-IU-2014–9429); N of Lubang, staCP 11, 14°00'N, 120°19'E, 194–196 m, 21 Nov 1980: 2 males 6.1, 7.3 mm (MNHN-IU-2014–9427), 1 male 9.5 mm (MNHN-IU-2014–9428); N of Lubang, staCP 18, 14°00'N, 120°17'E, 188–195 m, 22 Nov 1980: 1 female 6.4 mm (MNHN-IU-2014–9430); N of Lubang, staCP 19, 14°01'N, 120°18'E, 189–192 m, 22 Nov 1980: 3 males 4.8–7.5 mm, 2 females 5.7, 5.8 mm, 1 ovig 6.0 mm (MNHN-IU-2014–9404); N Lubang, staCP 53, 14°01'N, 120°17'E, 215–216 m, 27 Nov 1980: 1 male 7.2 mm (MNHN-IU-2014–9433); N of Lubang, staCP 68, 14°00'N, 120°17'E, 195–199 m, 29 Nov 1980: 1 male 5.2 mm (MNHN-IU-2014–9434); N of Lubang, staCP 71, 14°01'N, 120°19'E, 189–197 m, 30 Nov 1980: 1 female 6.0 mm (MNHN-IU-2014–9435); between Luçon and Lubang, staCP 80, 13°45'N, 120°37'E, 178–205 m, 1 Dec 1980: 1 female 5.1 mm (MNHN-IU-2014–9436). MUSORSTOM 3, NOCoriolis: W of Luçon, staCP 90, 14°00'N, 120°19'E, 195 m, 31 May 1985: 134 males 5.1–9.4 mm, 108 females 4.6–8.7 mm, 8 ovig females 6.4–7.8 mm (MNHN-IU-2014–9411), 16 males 5.1–9.7 mm, 11 females 4.9–7.5 mm, 9 ovig females 6.1–7.5 mm (MNHN-IU-2014–9413). PANGLAO 2004: sta T2, Bolod, Panglao Island, 9°32.4'N, 123°47.8'E, 152 m, coarse sand, 31 May 2004: not examined, color photos (#48, 54), Fig. 8A, B (ZRC or NTOU); Balicasag, [sta number unknown], May 2004: 1 male 12.1 mm (USNM 1441800). LUMIWAN 2008: NODA-BFAR, staCP 2870, 14°02'N, 120°17'E, 183–188m, 24 Mar 2008: 1 male, not examined (MNHN); [station unknown]: specimen not examined, color photograph, Fig. 28A.

Papua New Guinea: BIOPAPUA, NOAlis: Manus Island SE point, staCP 3693, 02°10'S, 147°17'E, 300 m, 29 Sep 2010: 2 males 5.2, 6.7 mm (MNHN-IU-2014–2447), 10 males 4.3–6.7 mm, 6 females 4.2–5.3 mm, 4 ovig females 5.8–6.4 mm (MNHN-IU-2014–2653).

Indonesia: Danish Kai Islands Expedition: sta 44, 05°39'S, 132°23'E, 268 m, 30 Apr 1922: 1 female 12.2 mm (ZMUC-CRU–006723), 1 female 6.3 mm (ZMUC-CRU–006724); sta 49, 05°37'10"S, 132°24'E, 245 m, 3 May 1922: 1 female 8.7 mm (ZMUC-CRU 007031); sta 50, 05°34'S, 132°25'4"E, 233 m, 4 May 1922: 1 male 9.2 mm (ZMUC-CRU–006725). Dr. Th. Mortensen’s Expedition: Java, sta 2, 07°33'S, 114°36'E, 200 m, 3 April 1929: 1 male 8.6 mm (ZMUC-CRU–006987). KARUBAR, RVBaruna Jaya 1: Kai Islands, staCP 35, 06°08'S, 132°45'E, 390–502 m, 27 Oct 1991: 1 female 6.9 mm (USNM 1441994); Tanimbar Islands, staDW 49, 08°00'S, 132°59'E, 206–210 m, 29 Oct 1991: 1 male 3.6 mm (USNM 1441991).

Fiji: BORDAU 1, NOAlis: Lau Ridge, Lakeba, staDW 1463, 18°10'S, 178°44'W, 300–400 m, 6 Mar 1999: 1 male 10.7 mm (MNHN-IU-2014–9364); Lau Lakeba Ridge, staDW 1507, 18°09'S, 178°38'W, 255–290 m, 13 Mar 1999: 1 male 5.1 mm (MNHN-IU-2014–9365).

New Caledonia: MUSORSTOM 5, NOCoriolis: Coral Sea, Lord Howe Ridge, Capel Bank, staCP 275, 24°46.60'S, 150°40.30'E, 285 m, 9 Oct 1986: 1 male 4.3 mm (USNM 1441993); Coral Sea, Lord Howe Ridge, Argosta Bank, sta DC 291, 23°07.70'S, 159°28.40'E, 300 m, 11 Oct 1986: 3 females 4.8–5.7 mm (USNM 1441992). MUSORSTOM 6, NOAlis: NW of Lifou, staCP 419, 20°42'S, 167°04'E, 283 m, 16 Feb 1989: 2 males 5.7, 5.8 mm, 2 females 5.7, 6.0 mm (USNM 1441990). LIFOU 2000, NOAlis: Santal Bay, in front of Hacu Hutighé islet, staDW 1647, 20°42'S, 167°08'E, 150–200 m, 6 Nov 2000: 1 female 11.4 mm (MNHN-IU-2014–9376). NORFOLK 1, NOAlis: Norfolk Ridge, Kaimon-Maru Bank, staCP 1676, 24°44'S, 168°09'E, 227–232 m, 22 Jun 2001: 1 female 8.5 mm (MNHN-IU-2014–9356); Norfolk Ridge, Kaimon-Maru Bank, staCP 1683, 24°44'S, 168°07'E, 248–272 m, 22 Jun 2001: 1 male 7.8 mm (MNHN-IU-2014–9361). NORFOLK 2, NOAlis: Kaimon-Maru Bank, staDW 2093, 24°44'S, 168°09'E, 230 m, 29 Oct 2003: 1 female 10.3 mm (MNHN-IU-2014–9387); Kaimon-Maru Bank, staCP 2095, 24°46'S, 168°10'E, 283–310 m, 29 Oct 2003: 1 female 12.5 mm (MNHN-IU-2014–9384). EBISCO, NOAlis: Capel Bank, staCP 2492, 24°44'S, 159°41'E, 285 m, 6 Oct 2005: 1 male 4.3 mm (ex MNHN-IU–2014–9401, USNM 1441984); N of Bellona, staDW 2578, 20°21'S 158°40'E, 440–505 m, 14 Oct 2005: 1 female 3.0 mm (USNM 1441995).

Eastern Australia: Queensland, Nimbus 1/68, sta 29, 26°30'S, 153°44'E, 184 m, 29 Jul 1968, coll. AJ Bruce: 1 male 7.0 mm (MNHN-IU-2014–9403, = MNHN-Pg 3670); sta 39, [same coordinates, depth as sta 29], 30 Jul 1968: 1 male 8.0 mm (MNHN-IU-2014–9410).

[Locality uncertain]: INVMAR: sta 15, [coordinates on label in error], 240 m, [no day] April 1929: 1 male 10.3 mm, 1 female 3.9 mm (MNHN-IU-2014–9416); sta 50, 233 m, [no other data]: 1 ovig female 8.1 mm (MNHN-IU-2014–9414); sta 52, [no other data]: 2 males 8.6, 12.7 mm (MNHN-IU-2014–9418, = MNHN-Pg 2313); sta 66, [no other data]: 2 females 5.4, 7.8 mm (MNHN-IU-2014–9422, = MNHN-Pg 2316); sta 125, 200 m, 4 Mar 1977 [no other data]: 1 female 10.9 mm (MNHN-IU-2014–9405); [no data]: 5 males 6.6–7.6 mm (MNHN-IU-2014 9415), 1 ovig female 7.1 mm (MNHN-IU–2014–9423, = MNHN-Pg 2315).

Redescription

Shield (Figs 1A, 2A, 3B) subtriangular, ca. 1.2 times as long as broad; dorsal surface glabrous except for scattered setae and transverse fringe of short setae on sloping anterior margins of gastric region; anterior margin between rostrum and lateral projections concave; lateral projections broadly triangular, each terminating in small spine; posterior margin roundly truncate; lateroventral distal angle produced into strong spine adjacent to proximal margin of first segment of antennal segment, usually with 1 small sharp or blunt spine dorsally. Rostrum (Figs 2A, B, 3B) bluntly subtriangular, arched dorsally, strongly produced and extending slightly beyond distal margin of ocular acicles; with distinct rounded dorsal longitudinal ridge having few short setae laterally, ending smoothly or with 1 or 2 minute subterminal spines. Branchiostegites (Fig. 2B) unarmed except for 1 or 2 spines on dorsodistal angle of anterodorsal plate, and setose distal margin.

Figure 1.

A–C Paguropsis typica Henderson, 1888, after Boas (1926: figs 1, 11A, B): A habitus B, C female right side with carcinoecium and pereopods 1–3 removed, with brood pouch (B) and with brood pouch folded posteriorly (C) showing pleopods D carcinoecium: Epizoanthus paguropsidis Ates, 2003 [nomen nudum], after Boas (1926: fig. 2) E Paguropsis andersoni (Alcock, 1899), after Alcock (1902: fig. 2), habitus.

Figure 2.

A, B Paguropsis typica Henderson, 1888 male, 14.6 mm, Philippines, USFCAlbatross, sta 5409 (USNM 1107574) C, D Paguropsis andersoni (Alcock, 1899) lectotype male, 18.3 mm, Laccadive Sea, Indian Ocean, HM Indian Marine Survey Steamer Investigator (USNM 42719). A, C dorsal view B, D right side of shield and rostrum, branchiostegite, and anterodorsal portion of posterior carapace. Abbreviations: apb, anterodorsal plate of branchiostegite; mp, median plate; cll, carapace lateral lobe; pmp, posteromedian plate. Scale bars: 10 mm (A, C), 2 mm (B, D).

Ocular peduncles ca. 0.5 length of shield, constricted medially and noticeably broadened distally, glabrous or at most with row of short dorsomedian row of short setae; corneas strongly dilated, diameter 0.5–0.6 total peduncular length (including the cornea). Ocular acicles small, triangular, each armed with distal or dorsodistal spine often directed anterodorsally.

Antennular peduncles when fully extended overreaching distal margins of corneas by full length of ultimate peduncular segments. Ultimate and penultimate segments glabrous or at most with scattered short setae. Basal segment with ventromesial tuft of setae distally; lateral face with distal subrectangular lobe, small medial spine, and setose lobe proximally.

Antennal peduncles overreaching distal corneal margins by 0.3–0.4 lengths of ultimate segments. Fifth and fourth segments unarmed except for scattered setae. Third segment with spine at ventrodistal angle. Second segment with dorsolateral distal angle produced, terminating in small, usually bifid spine; mesial margin rounded, setose, dorsomesial distal angle with small, usually blunt spine. First segment unarmed. Antennal acicle reaching level of distal portion of optic calathus, slender, terminating in sharp spine, with long setae mostly distally; usually armed with row of 2 or 3 minute spines lateroproximally. Antennal flagellum long, reaching to distal end of cheliped fingers, articles with scattered short setae (< 1 flagellar article in length) and 1 or 2 longer setae (ca. 2 flagellar articles in length) every 12 articles or so.

Mandible (Fig. 4A) with stout palp. Maxillule (Fig. 4B) with recurved external lobe of endopod nearly as long as endopod. Maxilla (Fig. 4C) with endopod not exceeding distal end of scaphognathite. Maxilliped 1 (Fig. 4D) with endopodite bent medially nearly at right angle, reaching distal end of exopod; with oval-shaped epipod. Maxilliped 2 (Fig. 4E) without distinguishing characters. Maxilliped 3 (Fig. 4F) exopod 4.5 times as long as broad; ischium having crista dentata armed with 15–17 small subequal (except for larger distal and proximal) corneous-tipped teeth; merus with 3–5 small spines on ventral margin, and usually two small spines on ventromesial distal angle; basis with row of small spines on mesial margin; coxa with ventromesial angle strongly produced ventrally, with 2–4 small spines and fringe of setae; sternite VIII narrow, with setose lobe on each side of midline.

Figure 3.

Paguropsis typica Henderson, 1888, Philippines, USFCAlbatross, sta 5409: A, B, D male, 14.6 mm, C female, 7.1 mm (USNM 1107574). A gill lamella B shield and cephalic appendages, dorsal C left side of posterior thorax and pleon showing brood pouch (bp), lateral D uropods and telson, dorsal. Abbreviations: cll, carapace lateral lobe; bp, brood pouch. Scale bar: 0.5 mm (A), 4 mm (B), 2 mm (C, D).

Figure 4.

Paguropsis typica Henderson, 1888, female, 8.5 mm, Philippines, USFCAlbatross, sta 5409 (USNM 1107574), left mouthparts, internal view: A mandible B maxillule C maxilla D maxilliped 1 E maxilliped 2 F maxilliped 3. Scale bars: 1 mm (A–E), 2 mm (F).

Chelipeds (Figs 1A, 2A, 5A) subequal, similar in armature and setation; dorsal surfaces of chelae and carpi covered with moderately dense tufts or short rows of bristle-like setae not hiding ornamentation beneath; ventral surfaces of palms smooth except for two submedian longitudinal rows of well-spaced low tubercles each with tuft of long bristle-like setae. Fingers with narrow hiatus proximally, forming spoon-like shape in ventral view when closed; each finger terminating in small curved corneous claw and subdistal blunt calcareous tooth ventral to claw, both claws and teeth interlocking when fingers closed; cutting edge of dactyl with row of small, fused corneous teeth on distal one-third, and row of unequal calcareous teeth on proximal two-thirds; cutting edge of fixed finger with row of blunt calcareous teeth decreasing in size distally. Dactyl ca. 1.2 times as long as palm; dorsal surface somewhat convex, armed with small spines proximally, dorsomesial margin rounded; ventral face with well-spaced tufts of long bristle-like setae, lacking spines. Fixed finger with dorsal, lateral, and ventral surfaces similar to dactyl in armature. Palm slightly shorter than carpus; dorsal surface covered with moderately dense, well-spaced small spines, accompanied by tufts of setae, arranged mostly in longitudinal rows (some extending to bases of fingers), and dense patch of plumose setae medially near base of fingers; dorsomesial margin with double row of well-spaced spines and tufts of long setae; dorsolateral margin rounded, not delimited, with irregular rows of small tubercles or spines, each accompanied by long setae. Carpus ca. 0.5 length of merus; dorsal surface with scattered simple spines or short transverse rows of 2 or 3 small spines accompanied by tufts of setae; dorsomesial margin with row of spines accompanied by tufts of setae, and dorsodistal spine; dorsolateral margin rounded; ventral surface smooth, with fringe of long setae on ventrodistal margin. Merus nearly as long as chela, subtriangular in cross-section; dorsal margin with row of protuberances each bearing transverse row of setae, ventromesial and ventrolateral margins each with row of spines with tufts of long setae; lateral and mesial surfaces with tufts of long and short setae mostly on ventral half. Ischium with row of small spines on ventrolateral margin. Basis with ventromesial row of long setae. Coxa with well-marked longitudinal fissure (Fig. 5B) on ventral surface.

Figure 5.

A, B Paguropsis typica Henderson, 1888 male, 14.6 mm, Philippines, USFCAlbatross, sta 5409 (USNM 1107574); C, D Paguropsis andersoni (Alcock, 1899) lectotype male, 18.3 mm, Laccadive Sea, Indian Ocean, HM Indian Marine Survey Steamer Investigator (USNM 42719). A, C chelipeds, dorsal B, D coxae of pereopods 1–5, sternites IX–XIII, and anterior portion of pleon with gonopods 1 and 2 (arrow in B indicates keel-like anteroventral margin of coxa). Abbreviations: roman numerals refer to sternites; C1–5, coxae of pereopods 1–5; G1, G2, gonopods 1 and 2; lf, longitudinal fissure. Scale bars: 5 mm (A, C), 2 mm (B), 4 mm (D).

Pereopods 2 and 3 (Figs 1A, 2A, 6A–D, 8A) similar in armature and setation, distinctly dissimilar in length, with pereopod 2 shorter than pereopod 3. Dactyls 1.5 (pereopod 2) or 2.5 (pereopod 3) times as long as propodi, each terminating in sharp corneous claw, lateral and mesial surfaces flat or very weakly convex; dactyl of pereopod 2 broadly curved on distal half; dactyl of pereopod 3 slender, nearly straight except for broadly curved distally near claw, from 1.6–1.8 times as long as dactyl of pereopod 2; dorsal margins with tufts of long setae, ventral margins with row of usually 14 short, minutely obscure corneous spinules (pereopod 2) or lacking spines or spinules (pereopod 3). Propodi 1.2 length of carpi; surfaces unarmed except for tufts of long setae on dorsal and ventral margins. Carpi unarmed except for tufts of setae dorsally and ventrodistally. Meri with fringe of long setae on ventral margins; ventral margin of pereopod 2 with row of few small, well-spaced blunt spines hidden by setae. Ischia unarmed except for scattered setae or tufts of setae (pereopod 2) or with ventral row of small spines (pereopod 3). Coxae of pereopods 3 (Fig. 5B) separated by 0.3 ventral length of 1 coxa. Sternite XI (between pereopods 3; Fig. 5B) having anterior lobe slightly concave and short setae on distal margin; posterior lobes each with transverse fringe of setae.

Pereopod 4 (Fig. 6E, F) with chela 1.2 times as long as carpus and 3 times as long as high, palm 2.3 times as long as high. Dactyl and fixed finger widely gaping, each terminating in sharp, inwardly curved corneous claw crossing at tips when closed. Dactyl strongly curved inward, dorsal margin with row of short, sparse setae; cutting edge with ventrolateral row of 5–7 small corneous-tipped spines (in addition to corneous claw). Fixed finger curving inward, cutting edge of fixed finger with 3–5 corneous-tipped spines (in addition to corneous claw) arranged like bear claw; lateral face usually with one or two minute scale-like corneous spines near base of finger. Palm straight, dorsal margin with dense fringe of long setae often interspersed with fringe of shorter setae (occasionally slightly thickening distally), and few tufts of setae on ventral margin continued on fixed finger. Carpus unarmed except for fringe of long setae dorsally and scarce, moderately long setae ventrally. Merus long, 0.6 times as long as meri of pereopods 2 and 3. Sternite XII (between pereopods 4; Fig. 5B) broad, with fringe of long dense setae.

Figure 6.

Paguropsis typica Henderson, 1888, male, 14.6 mm, Philippines, USFCAlbatross, sta 5409 (USNM 1107574). A left pereopod 2, lateral B dactyl of same, mesial C left pereopod 3, lateral D dactyl of same, mesial E left pereopod 4, lateral F dactyl and fixed finger of same, lateral G left pereopod 5, lateral. Scale bars: 5 mm (A–D), 2 mm (E, G), 1 mm (F).

Pereopod 5 (Fig. 6G) with chela 0.7 times as long as merus, with long, brush-like setae on dorsomesial and ventromesial faces; merus and carpus each with dorsal and ventral row of long setae. Dactyl with rasp on ventral face. Propodal rasp consisting of minute, ovate scales, occupying 0.1 length of propodus. Ischium with setae dorsally and ventrally. Coxa with fringe of long setae on ventrodistal margin.

Male gonopod 1 (Fig. 7A, C) with inferior lamella armed on distal margin with posterior row of slender, semitransparent hook-like spines, and 2 anterior rows of short straight or slightly curved corneous spines. Gonopod 2 (Fig. 7A, B) with distal segment strongly twisted distally, densely setose. Usually with unpaired, reduced pleopods 3–5 on left side or less frequently on right side, as follows: biramous or uniramous pleopod 3 and 4, and lacking or rarely with uniramous pleopod 5 (see “Variations”).

Figure 7.

Paguropsis typica Henderson, 1888, Philippines, USFCAlbatross, sta 5409 (USNM 1107574): A–C male, 14.6 mm, D female, 7.1 mm. A gonopods 1 and 2 in situ, ventroposterior B left gonopod 2, lateral, C distal portion of left gonopod 1, anterior D female gonopods 1 in situ, sternite XIII and coxae of pereopods 5. Abbreviations: G1, G2, gonopods 1 and 2. Scale bar: 1 mm (A, B), 0.25 mm (C), 0.5 mm (D).

Female with unpaired pleopods 2–5 usually on left side or less frequently on right side, as follows: pleopods 2–4 biramous, well developed, and reduced biramous or uniramous vestigial pleopod 5. Brood pouch (Fig. 3C) large, subquadrate, distal margin scalloped and fringed with setae (see “Variations”).

Uropodal exopods (Fig. 3D) slender, broadly curved, terminating in strong spine, anterior margin with fringe of long setae and row of well-spaced corneous-tipped spines; endopods short, strongly curved, anterior margin with long setae and row of corneous-tipped spines; protopods with strong, curved proximal spine.

Telson (Fig. 3D) subrectangular, wider than long; posterior lobes separated by shallow median cleft, terminal margins unarmed except for fringe of long setae.

Genetic data

See Table 1.

Color

(Figs 8A, B, 28A). Shield evenly orange. Ocular peduncles orange except for white along proximal and proximomesial margins of black corneas, orange tone darker medially; ocular acicles light orange fading to weak orange distally. Antennules light orange, flagella of similar color except for transparent bluish color distally. Antennal peduncles light orange, and similar but lighter toned and somewhat transparent flagella. Chelipeds with dactyl and fixed finger white; palms mostly white except for light orange distally and reddish proximally with white spines or tubercles; carpi red with white spines or tubercles; meri red except for orange on lateral and mesial surfaces, and white spines or tubercles. Pereopods 2 and 3 red with white spots on lateral faces of dactyls, carpi and propodi; dactyls each with uneven or interrupted white band proximally; meri with orange lateral and mesial faces; ischium with orange.

Figure 8.

A, B Paguropsis typica Henderson, 1888, Philippines, PANGLAO 2004, sta T2 [#48] (A) and T2 [#54] (B) (photographs: T-Y Chan): A habitus, with carcinoecium B habitus, with carcinoecium removed C Paguropsis andersoni (Alcock, 1899), habitus, MAINBAZA staCC 3159 (#29) (MNHN) (photograph: T-Y Chan) D Paguropsis confusa sp. n., MAINBAZA, staCP 3134 (#23) (MNHN) (photograph: T-Y Chan).