Paguropsis typica Henderson, 1888

Lemaitre, Rafael, Rahayu, Dwi Listyo & Komai, Tomoyuki, 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, pp. 17-97 : 22-36

Paguropsis typica Henderson, 1888 Figs 1 A–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.

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.

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 ex cept 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.

Pereopods 2 and 3 (Figs 1A, 2A, 6 A–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, mi nutely 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 pereo pods 2 and 3. Sternite XII (between pereopods 4; Fig. 5B) broad, with fringe of long dense setae.

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”).

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.

Distribution.

Western Pacific: from Japan, off Daito Islands, Ryukyu Islands ( Miyake 1982), and Kyushu-Palau Ridge ( Baba et al. 1986, this study); South China Sea; Philippines; New Guinea; Indonesia (Java and Arafura Seas); Fiji Islands; New Caledonia; and eastern Australia. Depth: 136 to 1125 m.

Habitat and symbiont.

Found with indeterminate species of acontiate anemone (see “Remarks” under genus).

Variations.

Aside from the meristics accounted for in the above redescription, this species is relatively constant in morphology. The only remarkable variation is in the position of unpaired pleopods 2-5 in females, and presence and degree of development of pleopods 3-5 in males. Females of Paguropsis typica have unpaired pleopods 2-5 on either side, with pleopods 2-4 well developed, biramous and ovigerous, whereas pleopod 5 is considerably reduced or absent. Males have unpaired pleopods 3-5 on either side, all considerably reduced, uni- or biramous, although pleopod 5 or occasionally all pleopods 3-5, can be absent. McLaughlin and Lemaitre (1997: 111) erroneously stated that males of Paguropsis lacked unpaired pleopods. Based on the specimens examined with complete pleons (n = 45), we observed that in females, 65.5% had pleopods 2-5 on the left side, 24.2% on the right side (often pleopod 5 is absent), and 10.3 % did not have any unpaired pleopods on either side. In males, 75.1% had one or more of pleopods 3-5 on the left side, 18.7% on the right side, and 6.2% did not have any unpaired pleopods on either side.

Affinities.

Except for the drastic difference in coloration, Paguropsis typica and P. confusa sp. n. are remarkably similar in morphology, and can thus be easily confused unless fresh specimens that still retain their color patterns are available (Figs 8A, B, D, 28A, C, D). In the absence of color information, the two can be separated with difficulty using only subtle characters, such as the degree of setation and strength of armature of chelipeds and pereopods 2 and 3 (less dense setation and spination in P. typica than in P. confusa sp. n.), and minor differences on the lateroproximal surface of the dactyl of pereopod 3 (convex in P. typica vs. slightly concave in P. confusa sp. n.).

General similarities exist between Paguropsis typica and P. andersoni , in particular the cephalic appendages (i.e., dilation of corneas, development of antennular and antennal peduncles), and shape of shield (i.e., posterior half of shield narrowly subtriangular). However, the two species can immediately be differentiated by the shape of the dactyls of pereopods 2 and 3 (Figs 1A, E, 2A, C, 6 A–D, 8 A–C, 10 A–D), which are distinctly more slender and narrower in P. typica than in P. andersoni ; and more clearly, the lateral face of the dactyl of pereopod 3 is evenly flat or convex throughout in P. typica , whereas the surface is distinctly concave (and often weakly calcified) on the proximal one-third in P. andersoni . Both species have numerous tufts of long setae on chelipeds and ambulatory legs, but in P. typica these are not as dense or as stiff and bristle-like as in P. andersoni . The antennal acicles are shorter, reaching approx. to the level of distal portion of optic calathus, and the chela of each pereopod 4 is more elongate (1.2 times as long as carpus), in P. typica ; whereas the acicles slightly exceed the distal margins of corneas, and the palm of each chelate pereopod 4 is shorter (0.6 times as long as carpus), in P. andersoni . Color differences also exist between these two species, and these are discussed under “Remarks” for P. andersoni .

Remarks.

Alcock (1905) corrected the spelling of Henderson’s (1888) species for gender agreement, from typicus to typica , although as shown here, his specimens actually represent Paguropsis andersoni . Nevertheless, various carcinologists ( Pzibram 1905, Boas 1926, Rabaud 1941, Thompson 1943, Kamalaveni 1950, Gordan 1956) continued to use the original spelling P. typicus .

Since Henderson’s (1888) description of Paguropsis typica a good number of biologists have used Henderson’s taxon name in faunal inventories or checklists (e.g., Estampador 1937, Miyake 1982, Baba et al. 1986, McLaughlin et al. 2010, Malay et al. 2018), as example of symbiosis ( Balss 1924, 1956, Ross 1983, Ates 2003, Williams and McDermott 2004), in textbooks on biology or anatomy of invertebrates ( Nicol 1967, Kaestner 1970), in phylogenetic analyses ( Richter and Scholtz 1994), and reviews of hermit crab housing ( McLaughlin 2015). Of these, records from the Indian Ocean are referred to P. andersoni (see “Remarks” under P. andersoni ). Gordan (1956), in her bibliography of pagurids, did include under Paguropsis typica (using the spelling P. typicus ), references to both Henderson’s (1888) original description and Alcock’s (1899) Chlaenopagurus andersoni (= Paguropsis andersoni ); thus, her taxon concept included both P. typica and the herein resurrected P. andersoni . The studies by Balss (1924, 1956) did include figures or information that clearly are referable to P. typica or P. andersoni , and thus are herein listed accordingly in the synonymy for each of these two taxa as "in part". Miyake (1982) and Baba et al. (1986) reported on new specimens from Japanese waters. The specimen from off Daito Islands, shown in Miyake’s (1982) book, has an abnormally small left cheliped perhaps in the process of regeneration, but agrees well with P. typica in the general coloration, confirming its identity. The specimens from the Kyushu-Palau Ridge examined in this study (CBM-ZC 4898, 4899) originated from the same source as the material studied by Baba et al. (1986).

Schäfer et al. (1983) studied the morphology of an aberrant actinian which they found attached to the underside of the thorax of planktonic glaucothoe larvae they identified as Paguropsis typica . However, in a worldwide review of hermit crab biocoenoses Williams and McDermott (2004, based on pers. comm. from PA McLaughlin), questioned the identity of the hermit crab host name used by Schäfer et al. (1983). We have examined the glaucothoe larval specimens used by Schäfer et al. deposited in ZMUC, and found the larvae to actually belong to one or more indeterminate species of the family Parapaguridae . These larvae are of the type similar to " Glaucothoe peronii ", which were shown to represent parapagurids by de Saint Laurent-Dechancé (1964). Glaucothoe stages of several species of parapagurids have been described by Lemaitre and McLaughlin (1992) and Lemaitre (1997). Our assignment of Schäfer et al.'s (1983) glaucothoe to parapagurids is made based on the following characters present in those larvae: 1) maxilliped 1 lacking flagellum (a major parapagurid character); 2) pereopod 4 semi-chelate and with a propodal rasp (it is uniquely chelate and lacking a propodal rasp in P. typica ); 3) pleonal pleura terminating ventrally in anteriorly directed hook-like process; 4) telson anterior half broad and rounded laterally, and narrow posterior half with long setae on terminal margin. Schäfer et al. (1983: fig. 12), however, based on the literature presented a map showing the known distribution of adult specimens of P. typica (misspelled therein also "P. tyica"), which includes historical records of both P. typica and the herein resurrected P. andersoni .