Pagurus Fabricius, 1775

Komai, Tomoyuki, 2003, Identities of Pagurus japonicus (Stimpson, 1858), P. similis (Ortmann, 1892) and P. barbatus (Ortmann, 1892), with description of a new species (Crustacea, Decapoda, Anomura, Paguridae), Zoosystema 25 (3), pp. 377-411 : 379-401

Genus Pagurus Fabricius, 1775

Pagurus japonicus ( Stimpson, 1858) ( Figs 1-5 )

Eupagurus japonicus Stimpson, 1858: 250 (type locality: Shimoda, Izu Peninsula, Japan); 1907: 226, pl. 25, fig. 2. — Alcock 1905: 177. — Terao 1913: 369 (part). — Nakazawa 1927: 203, fig. 1045.

Eupagurus japonicus ? – Miers 1880: 375, pl. 14, figs 6, 7 (= Pagurus hirtimanus Miers, 1880 ). See Remarks.

? Eupagurus japonicus – Balss 1913: 56. — Yokoya 1933: 85. See Remarks.

Pagurus japonicus – Gordan 1956: 331 (bibliography). — Miyake 1960: 90, pl. 45, fig. 4; 1965: 648, fig. 1096; 1975: 323, pl. 115, figs 7, 10; 1978: 94 (part), fig. 35, pl. 2, fig. 2; 1982: 125, pl. 42, fig. 1; 1991: 125, pl. 42, fig. 1; 1998: 125, pl. 42, fig. 1. — Miyake et al. 1962: 125. — Kim 1963: 300, fig. 18; 1964: 9; 1970: 13; 1973: 239, 602, fig. 58, pl. 71, fig. 38; 1985: 74. — Suzuki 1971: 97, pl. 34, fig. 3. — Miyake & Imafuku 1980: 60. — Takeda 1982: 68, fig.202; 1986: 124, unnumbered fig.; 1994: 228, fig. 3. — Yu & Foo 1990: 64, unnumbered fig. — Wang 1994: 570. — Asakura 1995: 362, pl. 97, fig. 3. — Kobayashi 2000: 186, unnumbered fig. — Minemizu 2000: 149, unnumbered fig. — Kato & Okuno 2001: 86 (top). — Park & Choi 2001: 138, unnumbered fig. Eupagurus barbatus Ortmann, 1892: 311 (type locality: two syntypes came from two different locations, Tokyo Bay and Sagami Bay). — Alcock 1905: 177. — Terao 1913: 365. — Yokoya 1933: 85. See Remarks.

Pagurus barbatus – Gordan 1956: 326. — Miyake et al. 1962: 125. — Miyake 1978: 105, fig. 41; 1982: 197 (list), 225 (key). — Miyake & Imafuku 1980: 60. Non Eupagurus japonicus – Ortmann 1892: 309, pl. 12, fig. 16 (= Pagurus rubrior n. sp.). See Remarks. Non Eupagurus barbatus – Balss 1913: 55 (= Pagurus similis ( Ortmann, 1892)) . See Remarks.

TYPE MATERIAL. — Holotype of Eupagurus japonicus Stimpson, 1858 : Shimoda, Izu Peninsula,, no longer extant.

Syntypes of Eupagurus barbatus Ortmann, 1892 : Tokyo Bay, 1880-1881, coll. L. Döderlein, 1 sl 16.0 mm ( MZS 484 ) ; Sagami Bay , 1880-1881, coll. L. Döderlein, 1 sl 15.2 mm ( MZS 485 ) .

MATERIAL EXAMINED. — Japan. Boso Peninsula, Kominato , scuba diving, 5 m, 23. VI.1994, coll. K. Nomura, 1 sl 15.3 mm ( CBM-ZC 2703 ) ; Hota, lobster net, 5-6 m, 20.XII.1998, coll. T. Komai, 1 sl 13.2 mm ( CBM-ZC 4847 ). — Off Hota , gill net, c. 30 m, 22.VIII.1997, coll. T. Komai, 1 sl 10.7 mm ( CBM-ZC 5673 ) ; Hota Fishing Port, 2-3 m, trap, 19. V.2000, coll. T. Komai, 1 sl 15.3 mm, 1 sl 13.7 mm ( CBM-ZC 6211 ). — Tokyo Bay, 1880- 1881, coll. L. Döderlein, 1 sl 16.0 mm (syntype of Eupagurus barbatus ; MZS 484 ). — Sagami Bay, Misaki , Miura Peninsula , 5.XI.1988, coll. A. Asakura, 1 sl 10.0 mm ( CBM-ZC 793 ), 1 sl 11.5 mm ( CBM-ZC 794 ) ; Kamegisho , dredge, 16 m, 28.VII.1960, Miyake det. No. 413, 1 ovig. sl 15.7 mm (NSMT-CrR 1831) ; similar locality, dredge, 14 m, 25.VII.1957, identified by Miyake (1978) as P. barbatus , det. No. 192, 1 sl 15.2 mm (NSMT-CrR 1373); 1880-1881, coll. L. Döderlein, 1 sl 15.2 mm (syntype of Eupagurus barbatus ; MZS 485 ). — Izu Islands, Sokodo, Hachijo Island , scuba, 5 m, 20.IX.2000, coll. S. Kato, 1 sl 9.3 mm ( CMNH-ZC 520 ). — Kii Peninsula, Kushimoto, scuba diving, depth unknown, coll. K. Nomura, 3 sl 7.2-9.3 mm, 2 sl 7.7, 8.1 mm, 1 ovig. sl 7.6 mm ( CBM-ZC 1046 ) ; Andonohana, Shionomisaki, scuba diving, 15 m, 7.IV.1985, coll. K. Nomura, 1 sl 7.9 mm (CBM- ZC 2407 ), 1 sl 5.3 mm, 1 ovig. sl 7.3 mm (CBM- ZC 4924 ). — Tosa Bay , Hane-misaki , Kochi, hand, subtidal, 26.IV.2001, coll. S. Wada, 3 sl 6.2- 7.7 mm, 1 sl 7.2 mm ( CBM-ZC 5893 ). — Kagoshima Bay , Shifushi , gill net, 5 m, 31.V.1997, coll. T. Kurozumi, 1 sl 8.2 mm ( CBM-ZC 3610 ). — Sea of Japan , Nakanoshima Island , Oki Islands , scuba, 5 m, 30.IX.1993, coll. K. Nomura, 1 sl 5.7 mm (CBM- ZC 5406 ) ; Takasa Beach, Echizen , Fukui Prefecture, scuba, 2 m, 9. V.2001, coll. T. Sugimoto, 1 sl 7.0 mm, 5 ovig. sl 7.0- 7.8 mm ( CBM-ZC 6448 ) ; Sayu Beach, Echizen , Fukui Prefecture, hand, 0-1 m, 3.IX.2001, coll. T. Sugimoto, 5 sl 6.9-13.4 mm, 2 sl 7.0, 12.1 mm ( CBM-ZC 6449 ) ; Yasujima, Mikuni , Fukui Prefecture, scuba, 6 m, 27.VIII.2001, coll. T. Sugimoto, 4 sl 5.4-13.3 mm, 1 sl 13.8 mm, 1 ovig. sl 7.4 mm (MNHN-Pg) .

DISTRIBUTION. — Pacific coast of Japan from Boso Peninsula to Kyushu, including Izu Islands; Sea of Japan coast of Honshu mainland to Kyushu; Korea; northern part of China; and northeastern part of Taiwan.

HABITAT. — Rocky bottom subtidal to 30 m; using various species of gastropod shells, e.g., Omphalius pfeifferi pfeifferi (Philippi, 1846) , Turbo cornutus Lightfoot, 1786 and Cymatium parthenopeum (Salis Marschlins, 1793) .

REDESCRIPTION

Eleven pairs of biserial phyllobranchiae.

Shield ( Fig. 1A ) 1.20-1.25 times as long as broad; anterior margin between rostrum and lateral projections concave; anterolateral margins sloping; posterior margin truncate; dorsal surface with six or seven pairs of tufts of short to long setae; paragastric grooves inconspicuous. Rostrum triangular, terminating acutely, exceeding lateral projections. Lateral projections obtusely triangular, with marginal or submarginal spine. Posterior carapace membranous except for weakly calcified submedian areas between cardiac sulcus and sulcus cardiobranchialis; posteromedian plate delimited by subparallel cardiac sulci; sulci cardiobranchiales extending to midway between posterior margin of shield and posterodorsal margin of carapace; branchial regions with scattered tufts of short to long setae.

Ocular peduncle ( Fig. 1A ) 0.40-0.50 time as long as shield in adults, weakly inflated basally, with row of tufts of setae dorsomesially; cornea weakly dilated, maximum diameter 0.30-0.35 of length of ocular peduncle and not much greater than basal width of ocular peduncle. Ocular acicle narrowly triangular, slightly curved ventrally, terminating bluntly and usually with small submarginal spine, moderately separated basally; dorsal surfaces grooved.

Antennular peduncle ( Fig. 1A ) overreaching cornea by 0.40-0.60 length of ultimate segment. Ultimate segment subequal in length to penultimate segment, slightly broadened distally in lateral view, with few tufts of long setae on dorsal surface. Penultimate segment with tuft of setae on dorsodistal margin. Basal segment with statocyst lobe bearing strong spine on laterodistal margin.

Antennal peduncle overreaching distal margins of cornea by 0.40-0.60 length of fifth segment. Fifth segment slender, with scattered short setae. Fourth segment stout, with few tufts of setae. Third segment with spine at ventrodistal mesial angle obscured by tufts of long stiff setae. Second segment with dorsolateral distal angle strongly produced, reaching midlength of fourth segment, terminating in simple or bifid spine partially obscured by stiff setae; dorsomesial distal angle with strong spine, several long stiff setae on mesial margin. First segment laterally with small submarginal spine, ventromesial distal margin with few spinules laterally. Antennal acicle moderately long, reaching or slightly overreaching distal margin of cornea, arcuate, terminating in acute spine; mesial margin with row of tufts of long stiff setae. Antennal flagellum shorter than fully stretched right cheliped, every article with some minute setae.

Mandible ( Fig. 2A ) with incisor process relatively narrow, not clearly dentate. Maxillule ( Fig. 2B ) with distal endite relatively narrow; endopod tapering distally, with apical seta, devoid of trace of outer lobe. Maxilla ( Fig. 2C ) with moderately broad scaphognathite; endopod not reaching distal margin of anterior lobe of distal endite. First maxilliped ( Fig. 2D ) with broad exopod. Second maxilliped ( Fig. 2E ) with moderately stout exopod; flagellum long. Third maxilliped ( Fig. 2F, G ) moderately slender; ischium with crista dentata consisting of row of blunt corneous teeth and with one to three (most frequently two) accessory teeth; merus with minute spinule on dorsodistal margin, no spine on ventromesial margin; carpus without dorsodistal spine; exopod slightly overreaching distal margin of merus.

Chelipeds grossly unequal. Right cheliped ( Figs 3 ; 4; 5A, B ) with chela about 1.60 times longer than greatest width at base of dactylus in females and small males, but noticeably elongate in large males, as much as 2.20 times longer than greatest width; dorsal surface of chela with numerous tufts of short to moderately short plumose setae, often obscuring spines and tubercles; lateral margin of chela strongly convex in females and small males, only weakly convex in large males. Dactylus shorter than palm and slightly overlapped by fixed finger; cutting edge bearing row of broad calcareous teeth and adjacent row of tufts of stiff setae, terminating in large calcareous claw; dorsal surface slightly convex, with closelyspaced, low, rounded tubercles on mesial side of midline proximally (few tubercles present near base of dactylus, each with capsule similar to those on palm), distally only with few tufts of setae; mesial margin noticeably sinuous, with row of large blunt or subacute spines; ventral face with numerous low broad tubercles and tufts of stiff setae. Palm shorter than carpus; dorsomesial margin delimited by row of small acute or subacute spines; dorsolateral margin with row of small spines decreasing in size proximally and row of tufts of stiff setae; dorsal surface slightly convex, covered with scattered, small, low tubercles frequently bearing capsules and with row of small acute or subacute spines on midline extending onto fixed finger (sometimes with additional row of small spines mesial to median row); corneous, spiniform capsules weakly curved backward, arising from anterodorsal or subcentral part of tubercle; mesial face of palm slightly concave, with row of small spines dorsally and low tubercles or protuberances ventrally, each accompanied by tuft of stiff setae; ventrolateral face (including fixed finger) with numerous scattered low tubercles accompanied by tufts of long setae; ventral surface with few low protuberances and tufts of stiff setae. Cutting edge of fixed finger with row of broad calcareous teeth, terminating in large calcareous claw. Carpus longer than merus; dorsomesial margin distinctly delimited by row of moderately small spines, and with tufts of long setae; dorsal surface with numerous capsulate tubercles and few moderately small spines, and with numerous tufts of short plumose setae; dorsolateral margin not delimited; lateral face with numerous low tubercles or protuberances accompanied by long plumose setae, ventrolateral distal margin with row of small tubercles or blunt spines; mesial face slightly concave, with numerous low protuberances accompanied by tufts of long stiff setae, mesiodistal margin with row of small spines; ventral surface with several minute to small tubercles and tufts of setae distally. Merus with short transverse rows of setae on dorsal surface; dorsodistal margin unarmed but with row of dense setae; in females and small males mesial face not particularly inflated ventrally, ventromesial margin distinct, with row of tiny spines and moderately dense long setae; in large males, mesial face strongly inflated ventrally, ventromesial part (ventromesial margin not sharply delimited) with few spinules and extremely dense cluster of long setae extending to mesial face; lateral face with scattered, small, low protuberances accompanied by short setae, ventrolateral margin with row of small spines, ventrolateral proximal corner somewhat produced in large males; ventral surface concave, with minute spinulose tubercles and numerous long setae (setae extremely dense in large males). Ischium with tufts of short setae on all faces; ventromesial margin with few small blunt tubercles; ventral surface with few large, rounded or flattened tubercles. Coxa without spines on distal margin, but with tufts of long setae ventromesially.

Left cheliped ( Figs 2H, I ; 4; 5C, D ) slightly overreaching base of palm of right cheliped to reaching base of dactylus of right cheliped, strongly compressed laterally, setation generally similar to that of right. Chela elongate subovate in dorsal view, about 2.80 times longer than greatest width at base of dactylus. Dactylus longer than palm, slightly curved ventrally; cutting edge with row of small calcareous teeth in proximal 0.50-0.60 and with row of small corneous teeth in distal 0.40- 0.50, terminating in large corneous claw; dorsomesial margin not distinctly delimited, but with row of blunt spines or tubercles decreasing in size distally; dorsal surface sloping mesially, proximally with row of spines or tubercles mesial to midline; mesial face with few low tubercles proximally. Palm about half length of carpus, triangular in cross section; dorsal surface elevated in midline but not forming distinct ridge or crest, with row of moderately large spines decreasing in size distally and extending onto proximal half of fixed finger; dorsolateral margin with row of small spines; dorsolateral and dorsomesial surfaces strongly sloping ventrally, former surface covered with numerous rounded tubercles, most provided with capsule, latter surface with scattered small, acute or subacute spines; dorsomesial margin not distinctly delimited; lateral face with closely spac- ed small to large blunt tubercles, several of which adjacent to dorsolateral margin provided with capsule; ventral surface somewhat inflated, with some large tubercles and few low protuberances accompanied by tufts of long setae. Carpus approximately as long as merus; dorsomesial margin with row of large acute spines; dorsolateral margin only weakly delimited, with row of four or five small spines; dorsal surface somewhat sloping with several capsulate tubercles, dorsodistal margin with row of small spines; mesial face with scattered low protuberances, mesiodistal margin smooth; lateral face with dense covering of rounded tubercles, most of which provided with capsule, ventrolateral distal margin strongly expanded, partially covering base of chela, with row of moderately strong spines; ventral surface sloping, with small spines and low protuberances. Merus with short transverse rows of setae on dorsal surface, dorsodistal margin without spine; mesial face with short transverse or obliquely transverse rows of long stiff setae dorsally and ventrally, ventromesial margin without spine; lateral face with numerous scattered low protuberances and minute, low tubercles, ventrolateral margin strongly expanded, with row of spines becoming longer distally; ventral surface weakly concave, with small low tubercles and numerous tufts of long stiff setae. Ischium and coxa similar to those of right cheliped in setation and armature.

Second and third pereopods ( Fig. 5 E-H) similar from right to left in armature and setation. Dactyli stout, 0.95-1.14 times as long as propodi on right second, 1.16-1.39 times as long on left third, in dorsal view straight, in lateral view slightly curved ventrally, terminating in moderately long to long corneous claws; dorsal surfaces each with tufts of setae and row of corneous spines increasing in length distally; lateral faces each with tufts of stiff setae dorsally and ventrally and with faint median sulcus proximally; mesial faces each with tufts of setae dorsally and ventrally and with short median sulcus proximally, unarmed in second, armed with two rows of corneous spines in third; ventral margins each with seven to 10 strong corneous spines. Propodi distinctly longer than carpi; dorsal surfaces each with short transverse rows of long setae, often extending to lateral face, but without spine; lateral faces each with short obliquely transverse rows of long setae dorsally and tufts of shorter setae ventrally; ventral surface with row of widely separated tufts of setae and small corneous spines. Carpi only with dorsodistal spine; dorsal surfaces

B

each with numerous long plumose setae; lateral faces each with tufts or short rows of long plumose dorsal to midline, and scattered tufts of short setae ventral to midline. Meri broad, each with dorsal and ventral tufts of long plumose setae; lateral faces each with few tufts of short setae; ventrolateral distal margins armed with one small subdistal spine on second, unarmed on third. Ischium with dorsal and ventral tufts of setae. Female with paired gonopores.

Fourth pereopods ( Fig. 1E, F ) semichelate, similar from right to left, but left slightly shorter than right. Dactylus curved ventrally, terminating in long corneous claw, with row of fine corneous teeth on ventral margin; preungual process arising just distal to row of corneous teeth, flexible. Propodal rasp composed of six or seven rows of corneous scales; all segments with dorsal and/or ventral tufts of long setae.

Fifth pereopod chelate; males with paired gonopores ( Fig. 1H ), each partially obscured by moderately long setae.

Third thoracic sternite with pair of minute spinule on either side of shallow median notch on anterior margin. Sixth thoracic sternite with anterior lobe ( Fig. 1G ) subsemicircular, with numerous setae on anterior face. Eighth thoracic sternite ( Fig. 1H ) developed anteriorly as two somewhat flattened subrectangular lobes separat- ed by shallow median depression, anterior margins each with row of setae.

Abdomen twisted. Males with four unpaired left (second to fifth) pleopods, all four unequally biramous (exopods well developed, endopods much shorter than exopod, but not rudimentary). Females also with four unpaired left pleopods, anterior three subequally biramous, fifth as in males. Uropods greatly asymmetrical; exopods and endopods both well developed rasps.

Telson ( Fig. 1I ) wider than long, with deep lateral indentations; posterior lobes slightly to somewhat asymmetrical, separated by small median cleft; terminal margins nearly transverse, each with row of four to six small spines and interspersed minute spinules, not extending to lateral margin.

COLORATION

In life: shield mottled with brown and blue-gray, median part paler. Posterior carapace generally brownish gray, scattered by transparent spots. Ocular peduncle generally white with broad dark brown band submedially, and with dark brown patch at base of cornea and tinge of blue just proximal to dark brown patch. Distal two segments of antennular peduncles each with broad band of reddish brown and tinge of blue distally; flagella reddish brown. Antennal peduncle with fifth segment having brown longitudinal stripes laterally and mesially on transparent background; second segment mottled with blue-gray and brown; antennal acicle brown in distal half and blue-gray in proximal half; flagellum banded with brown and white (every four or five articles brown and one article white). Third maxilliped generally brown, with spots of light gray or light blue-gray on dorsal surface of propodus, carpus and merus. Chelipeds generally brown; capsulate tubercles on chelae and carpi light gray or bluegray; spines or spiniform tubercles brown or yellowish brown, low tubercles on mesial faces of palms blue-gray; chelae with scattered spots of dark brown; meri generally brown, irregularly spotted by blue-gray. Dactyli of ambulatory pereopods banded with brown (in proximal 0.70) and white (in distal 0.30, except for terminal corneous claws); propodi banded with blue-gray (in distal 0.30-0.40) and brown or reddish brown (in proximal 0.60-0.70); carpi generally brown or reddish brown, with spots of blue-gray; meri gray-blue in distal half and brown in proximal half in general, distal blue-gray areas with large spot of dark brown dorsally, proximal brown area with large white patch dorsoproximally and some spots of blue-gray.

In preservative: blue gray or gray parts in life changed to light orange or yellow, and brown parts changed to darker orange or reddish brown.

SIZE

Males sl 5.7-16.0 mm; females sl 7.0- 15.7 mm; ovigerous females sl 7.0- 15.7 mm.

VARIATION

As is apparent from the description, this species exhibits a considerable variation in morphology of the right cheliped in males. In small males and females the ratio of “chela length/chela width” of the right cheliped is rather stable, about 1.50- 1.60; the setae covering dorsal surface of the chelae and carpi of the chelipeds are short, and the surface structures are clearly visible; the mesial face of the merus is not inflated; density of setae on the ventral surface of the merus is weak to moderate ( Fig. 4, bottom). In large males (sl> 14.0 mm), the right palm is noticeably elongate, with the ratio “chela length/chela width” attaining 2.30; the setae covering the dorsal surface of the chelae and carpi are longer and more dense, thus the surface structures are at least partially obscured; the mesial face of the merus is strongly inflated and the delineation of the ventromesial margin is reduced; the setae on the ventral surface are extremely dense, and partially extend to the mesial face ( Fig. 4, top).

The proportional length of the ambulatory dactyli is fairly variable. The dactylus of the right second pereopod is 0.95-1.14 times as long as the propodus; the dactylus of the left third pereopod is 1.16-1.39 times as long as the propodus.

REMARKS

Stimpson’s (1858) brief original description of Eupagurus japonicus was based on a single male specimen. The holotype was presumably destroyed in the Chicago fire of 1871 ( Rathbun 1883; Evans 1967). Nevertheless, some of the characters reported by Stimpson (1858, 1907) are sufficiently diagnostic in recognizing the species. These include the prominent, acute rostrum, the elongate ocular acicle with a grooved dorsal surface, the strongly inflated and hairy ventral surface of the merus of the right cheliped, and the ambulatory legs broadly banded with deeper red. The present specimens are assigned to Pagurus japonicus , as they agree entirely with Stimpson’s description in those diagnostic features. Stimpson’s (1907) description of the color as “inclining to orange or minutely mottled with red and yellow” rather agrees with the color of the ethanol preserved specimens.

During this study, it has been found that in the three East Asian species discussed, the tubercles on the dorsal surfaces of the chelae are provided with long slender capsules similar to those report- ed by McLaughlin (1997) for Pagurus capsularis McLaughlin, 1997 and P. pergranulatus (Henderson, 1896) and by de Saint Laurent & McLaughlin (2000) for P. sinuatus ( Stimpson, 1858) and P. hirtimanus ( Miers, 1880) . No reference has been made by previous authors (e.g., Ortmann 1892; Terao 1913; Miyake 1978, 1982) to distinctive capsulate structures on the tubercles of the chelae of Pagurus japonicus and Pagurus similis s.l. Further, the seven species mentioned all possess an unpaired second pleopod in males (thus the total number of unpaired pleopods in males is four) ( McLaughlin 1997; de Saint Laurent & McLaughlin 2000).

Pagurus japonicus appears closest to P. sinuatus known from southern Australia and Kermadec Islands (de Saint Laurent & McLaughlin 2000). Comparison with the description of P. sinuatus by de Saint Laurent & McLaughlin (2000) has shown that P. japonicus and P. sinuatus differ in the following respects. The shield is 1.20-1.25 times as long as broad in P. japonicus , but it is reportedly slightly longer than broad in P. sinuatus . The ocular peduncle is shorter but more slen- der in P. japonicus than in P. sinuatus ; the length of ocular peduncle is 0.50-0.60 of the shield length in P. japonicus , 0.55-0.70 in P. sinuatus ; the corneal diameter is 0.30-0.35 of the length of the ocular peduncle in P. japonicus , 0.38-0.45 in P. sinuatus . The antennal peduncle distinctly overreaches the distal margin of the cornea in P. japonicus , rather than just reaching or slightly overreaching it in P. sinuatus . The middorsal spines on the dactylus of the right cheliped are much smaller in P. japonicus than in P. sinuatus . The dorsal surface of the carpus of the right cheliped is entirely covered with low tubercles, including capsulate ones, in P. japonicus , but it bears a “smooth patch medially” in P. sinuatus . The tubercles on the lateral face of the carpus of right cheliped seem to be much more numerous in P. japonicus than in P. sinuatus . The lateral face of the carpus of the left cheliped is covered with numerous capsulate tubercles in P. japonicus , instead of low, flattened protuberances bearing marginal long setae in P. sinuatus .

Pagurus japonicus is immediately distinguished from P. rubrior n. sp. and P. similis by the elongate shield with a more strongly produced rostrum, the more strongly elevated median ridge on the left chela, the strongly compressed, deep carpus of the left cheliped, and the more robust and shorter dactyli of the ambulatory pereopods with fewer and less elongate mesial spines. Further, in P. japonicus , the dactyli of the ambulatory pereopods are devoid of white patches and red median stripes on the lateral and mesial surfaces that are present in P. similis and P. rubrior n. sp.

Pagurus japonicus differs from P. capsularis , P. hirtimanus and P. pergranulatus in the less dilat- ed cornea of the eye. In P. japonicus , the corneal diameter is not distinctly greater than the basal width of the ocular peduncle, while in the latter three species, the cornea is somewhat to strongly dilated, and its diameter exceeds the basal width of the ocular peduncle. Further, P. capsularis is distinguished from P. japonicus by the absence of tubercles on the dorsal surface of the carpus of the right cheliped, much more slender dactyli of the ambulatory pereopods, and the strongly oblique terminal margins of the telson. The more dense covering of short setae on the palm of the right cheliped separates P. hirtimanus from P. japonicus . Pagurus pergranulatus is characteristic in having a subacute lobe at the dorsomesial distal angle of the right palm (cf. Alcock & Anderson 1897: pl. 31, fig. 1).

Miers (1880) tentatively referred specimens from unknown locality in the Malaysian region to Eupagurus japonicus , although he suggested that his specimens were conspecific with a specimen from the Philippines named without description as Pagurus hirtimanus by White (1847), but differing from the original description of E. japonicus in the shape of ocular acicle and armature of the right chela. Miers’ specimens represent Pagurus hirtimanus Miers, 1880 , as previously indicated ( Lewinsohn 1969).

Ortmann’s (1892) report of Eupagurus japonicus , based on six specimens from Tokyo Bay, was brief and accompanied by rather diagrammatic illustrations. However, his illustration of the dactylus of the ambulatory leg (pl. 12, fig. 16m) clearly shows the presence of a patch and median stripe, being characteristic to P. similis s.l. In reference to the illustration, in his synonymy of Pagurus japonicus, Miyake (1978) suggested that Ortmann’s E. japonicus might actually represent P. similis , but he did not comment further. As noted previously, it has been found that Ortmann’s specimens of E. japonicus actually represent the new species P. rubrior n. sp. described in this paper.

Yokoya (1933) referred two males from southwest of Misaki at depth of 307 m and one ovigerous female from off Iki Island at depth of 110 m to Eupagurus japonicus . He gave no diagnostic information, and his specimens have not been available for study. Nevertheless, this study has shown that P. japonicus occurs in shallow waters from subtidal zone to about 30 m. It is likely that Yokoya was actually reporting a species other than P. japonicus . Thus Yokoya’s reference is included questionably in the synonymy.

Ortmann’s (1892) description of Eupagurus barbatus , based on two males, one from Tokyo Bay and one from Sagami Bay, was brief and no illustration was provided. He compared this species only to E. japonicus sensu Ortmann (= Pagurus rubrior n. sp.). Reexamination of the two syntypes has revealed that P. barbatus is conspecific with P. japonicus . The latter name has priority over the former name.

Terao’s (1913: 365, 369, 370) treatment of Eupagurus barbatus is somewhat confusing. He (p. 365) listed Eupagurus barbatus , suggesting that he recognized the species as valid, however he also included E. barbatus in the synonymy of E. japonicus . In the account of E. japonicus , he did not give any comments on his treatment of E. barbatus .

Balss (1913) reported E. barbatus from Sagami Bay on the basis of a single female specimen. In the text, Balss clearly mentioned that he compared his specimen with the type material of P. barbatus . However, reexamination of Balss’s specimen (ZSM 277/1) has shown that it actually represents P. similis , not P. japonicus . In the same report, Balss reported Eupagurus japonicus based on two specimens from Sagami Bay; however the two specimens were not located in the collection of ZSM. The misidentification of E. barbatus may reflect Balss’ misinterpretation of the specific identities of P. japonicus and P. similis . Thus it is difficult to determine what species Balss (1913) was actually reporting. His reference to E. japonicus has questionably been included in the synonymy.

Yokoya (1933) recorded Eupagurus barbatus from off Kinkazan, Miyagi Prefecture, and northeast of Honshu. Yokoya’s specimens have not been available for study. As Yokoya gave no diagnostic information, it is difficult to determine the identity of his specimens. At present, the occurrence of P. japonicus , P. similis and P. rubrior n. sp. in the Pacific coast of northeastern Honshu mainland northward from Boso Peninsula has not been confirmed, and it is highly likely that Yokoya’s specimens represent a species other than these three.

Alcock (1905) and Gordan (1956) listed Eupagurus barbatus and Pagurus barbatus respectively; however, these were bibliographic listings.

Miyake (1978) reported Pagurus barbatus based on a single male specimen from Sagami Bay (NSMT-CrR 1373). He distinguished P. barbatus from P. japonicus by the following features: 1) the palm of the right cheliped is provided with long soft hairs and median row of spiniform tubercles; 2) the merus of the right cheliped is thickly ornamented with long setae on the ventral surface; and 3) the dactyli of the ambulatory pereopods are shorter than the propodi. However, as mentioned in the part Variation, examination of the present material has shown that these characters are variable within a single species, and are not reliable for species discrimination. The dactyli of the second and third pereopods are in fact not shorter than the propodi in Miyake’s P. barbatus specimen. It must be concluded, therefore, that P. japonicus and P. barbatus sensu Miyake are conspecific. Thus, the reports of Pagurus barbatus by Miyake et al. (1962), Miyake & Imafuku (1980), and Miyake (1982) are all referred to P. japonicus .

One of the specimens used in his report of P. japonicus by Miyake (1978) (Miyake det. No. 528) differs from P. japonicus in the much broad- er, semioperculate right palm, which bears only short stiff setae. There is little doubt that this specimen represents an undescribed species. Formal description of a new species, however, is deferred until additional specimens become available for study.

Pagurus similis ( Ortmann, 1892) s.s. ( Figs 6A ; 7-11 )

Eupagurus similis Ortmann, 1892: 310 (type locality: Kagoshima, Japan). — Alcock 1905: 177. — Yokoya 1933: 86. See Remarks.

Eupagurus barbatus – Balss 1913: 55. Non Eupagurus barbatus Ortmann, 1892 (= P. japonicus ( Stimpson, 1858)) . See Remarks.

Pagurus similis – Gordan 1956: 335 (bibliography). — Miyake 1960: 90 (part); 1978: 103 (part); 1982: 125 (part); 1991: 125 (part); 1998: 125 (part). — Miyake & Imafuku 1980: 60 (part). — Takeda 1982: 67 (part). — Yu & Foo 1990: 66, unnumbered fig. See Remarks.

? Pagurus similis – Kim 1964: 9; 1970: 13; 1973: 240, 603, fig. 59; 1985: 74.

Non Pagurus similis – Miyake 1960: pl. 45, fig. 5; 1975: pl. 115, figs 6, 9; 1978: fig. 40, pl. 2, fig. 3; 1982: pl. 42, fig. 2. — Suzuki 1971: 97, pl. 34, fig. 4. — Kim 1973: pl. 7, fig. 39. — Takeda 1986: 124, unnumbered fig.; 1994: 228, fig. 5. — Asakura 1995: 362, pl. 97, fig. 4. — Kobayashi 2000: 186, unnumbered fig. — Minemizu 2000: 149, unnumbered fig. — Park & Choi 2001: 139, unnumbered fig. (= Pagurus rubrior n. sp.). See Remarks.

Non Eupagurus similis – Doflein 1902: 646 (= Pagurus dubius ( Ortmann, 1892)) .

TYPE MATERIAL. — Holotype: Kagoshima, Kyushu, Japan, 1880, coll. L. Döderlein, (size not indicat- ed), not located in the collection of MZS.

MATERIAL EXAMINED. — Japan. Boso Peninsula , off Takeoka, gill net, 80-100 m, 29.VIII.1994, coll. T. Komai, 1 sl 14.7 mm ( CBM-ZC 626 ) ; off Takeoka , gill net, 50-60 m, 18.II.1995, coll. T. Komai, 1 sl 11.9 mm ( CBM-ZC 1058 ) ; off Kanaya , gill net for scampi, 120-200 m, 4.IV.1995, coll. T. Komai, 1 sl 11.4 mm ( CBM-ZC 1219 ) ; SW of Katsuyama Ukishima Islet , gill net for scampi, 120- 200 m, 8. V.1995, coll. T. Komai, 1 sl 11.1 mm ( CBM-ZC 1611 ) ; off Takeoka , gill net, 50-60 m, 1. V.1996, coll. T. Komai, 1 ovig. sl 13.7 mm ( CBM-ZC 2572 ) ; off Takeoka , gill net, 30-50 m, 28.VIII.1996, coll. T. Komai, 1 sl 13.1 mm (CBM- ZC 2968 ) ; off Takeoka , gill net, 40-50 m, 9.X.1997, coll. T. Komai, 1 ovig. sl 13.0 mm ( CBM-ZC 3948 ) ; off Katsuyama Ukishima Islet , gill net for scampi, 100-150 m, 10.IV.1997, coll. T. Komai, 1

sl 9.7 mm ( CBM-ZC 3958 ) ; Tateyama Bay , TRV Shin’yo-maru, 1996 cruise, stn 16, dredge, 35°00.57’N, 139°41.45’E, 100-258 m, 24.X.1996, coll. T. Komai, 1 ovig. sl 7.7 mm ( CBM-ZC 4738 ) ; off Takeoka , gill net, 80-100 m, 13.III.1997, coll. T. Komai, 1 sl 10.2 mm (MNHN-Pg 6101) ; off Takeoka , gill net, 50-60 m, VIII.1997, coll. T. Komai, 1 ovig. sl 13.7 mm (MNHN-Pg 6100). — Sagami Bay, Fukuura, depth unknown, 10-20.XI.1903, coll. A. Haberer, 1 sl 10.5 mm, reported by Balss (1913) as Eupagurus barbatus ( ZSM 277 /1) ; W of Kamegi-sho Bank , 50 m, 18.III.1964, Miyake (1978) det. No. 545 (NSMT-CrR 2220), 1 sl 9.0 mm ; W of Jogashima Islet , 150 m, III.1987, coll. H. Ikeda, 2 sl 10.0, 10.3 mm, 1 sl 7.1 mm (HSM-Cra 0133) ; SW of Jogashima Islet , 120-140 m, III.1987, coll. H. Ikeda, 2 sl 9.3, 11.0 mm ( HSM) ; off Kamakura , gill net, c. 100 m, 15.III.2001, coll. H. Namikawa, 1 sl 12.4 mm (NSMT-Cr). — Sagami-nada, Okinoyama Bank, dredge, 80 m, 25.VII.1959, Miyake (1978) det. No. 294, 1 ovig. sl 7.7 mm (NSMT-CrR 1619) ; 5 km off SW of Jogashima Islet , Miura Peninsula, dredge, 100 m, 7. VI.1960, Miyake (1978) det. No. 373, 1 ovig. sl 7.7 mm (NSMT-CrR 1757) ; Okinoyama Bank , RV Tansei-maru, KT 95-5, stn TB18-2, 34°59’N, 139°39’E, dredge, 105-113 m, 21.IV.1995, coll. T. Komai, 2 sl 8.1, 9.2 mm ( CBM-ZC 1987 ) ; Okinoyama Bank , TRV Shin’yo-maru, 1996 cruise, stn 19, 34°58.47’N, 139°34.13’E, dredge, 121- 129 m, 24.X.1996, coll. T. Komai, 1 sl 8.6 mm ( CBM-ZC 4739 ). — Izu Islands, Takase Bank, TRV Shin’yo-maru, 1996 cruise, stn 8, 34°27.59’N, 139°11.94’E, dredge, 104-109 m, 24.X.1996, coll. T. Komai, 1 sl 7.4 mm ( CBM-ZC 4737 ). — Ohsumi Islands, Kuroshima Bank, TRV Toyoshio-maru, 1996- 5 cruise, stn 10, 30°42.07’N, 130°06.27’E, sledge net, 133 m, 3.VI.1996, coll. T. Komai, 2 sl 13.3, 13.7 mm, 1 ovig. sl 7.7 mm ( CBM-ZC 4732 ) .

Taiwan. Off Ta-Shi, I-Lan County, NE Taiwan, depth unknown, commercial trawler, 4.XII.1997, coll. T. Komai, 1 sl 9.9 mm ( NTOU).

DISTRIBUTION. — Pacific coast of Japan southward from Boso Peninsula to Ohsumi Islands, Sea of Japan coast of southern part of Honshu mainland, Korea, and northeastern part of Taiwan.

HABITAT. — Rocky or coarse sand bottom, from 30 to 200 m; using various gastropod shells, e.g., Bolma modesa (Reeve, 1843) , Bufonaria rana (Linnaeus, 1758) , Semicassis bisulcata persimilis Kira, 1959 , Tonna luteostoma (Küster, 1857) , Cymatium parthenopeum (Salis Marschlins, 1793) , and Siratus pliciferoides (Kuroda, 1942) .

REDESCRIPTION

Eleven pairs of biserial phyllobranchiae.

Shield ( Fig. 7A ) 1.00-1.10 times as long as broad; anterior margins between rostrum and lateral projections concave; anterolateral margins sloping or slightly terraced; posterior margin truncate; dorsal surface with four to six pairs of tufts of setae; paragastric grooves inconspicuous. Rostrum broadly triangular, rounded or terminating in acute or subacute spine, reaching or slightly overreaching lateral projections. Lateral projection obtusely triangular, with marginal or submarginal spinule. Posterior carapace membranous except for weakly calcified submedian areas defined by cardiac sulci and sulci cardiobranchiales; posteromedian plate defined by subparallel cardiac sulci; sulci cardiobranchiales extending to midway between posterior margin of shield and posterodorsal margin of carapace; branchial regions with few tufts of setae.

Ocular peduncle ( Fig. 7A ) 0.60-0.70 time as long as shield, slightly inflated basally, with row of tufts of setae dorsomesially; cornea weakly dilat- ed, maximum diameter about 0.30-0.35 of length of ocular peduncle and slightly greater than basal diameter. Ocular acicle ( Fig. 7C ) narrowly triangular, slightly curved ventrally, terminating subacutely or bluntly and usually with slender submarginal spine, moderately separated basally; dorsal surfaces grooved.

Antennular peduncle ( Fig. 7A ) overreaching cornea by 0.20-0.40 length of ultimate segment. Ultimate segment 1.20-1.40 times longer than penultimate segment, slightly broadened distally in lateral view, with few long setae on dorsal surface. Penultimate segment with few setae on dorsodistal margin. Basal segment with small spine on laterodistal margin of statocyst lobe.

Antennal peduncle ( Fig. 7A ) overreaching distal margin of cornea by 0.20-0.30 length of fifth segment. Fifth and fourth segments moderately slen- der. Third segment with spine at ventrodistal angle obscured by tufts of setae. Second segment with dorsolateral distal angle strongly produced, reaching midlength to distal margin of fourth segment, terminating in simple or bifid spine partially obscured by stiff setae; dorsomesial distal angle with small spine, several long stiff setae on mesial margin. First segment laterally with small submarginal spine, ventromesial distal margin with few spinules laterally. Antennal acicle long, reaching or slightly overreaching distal margin of cornea, arcuate, terminating in acute spine; mesial margin with row of tufts of long stiff setae. Antennal flagellum longer than fully extended right cheliped, every article with some minute setae.

Mouthparts ( Fig. 8 A-E) similar to those of P. japonicus . Endopod of maxillule with trace of outer lobe ( Fig. 8B ). Third maxilliped ( Fig. 1F, G ) with one or two (rarely three) accessory teeth on ischium.

Chelipeds grossly unequal. Right cheliped ( Figs 9 A-C; 10) with chela 1.50-1.70 times longer than greatest width at base of dactylus in females and small males, but noticeably elongate in large males, length attaining twice maximum width; lateral margin of chela in dorsal view strongly convex in females and small males, only slightly convex in large males. Dactylus longer than palm and slightly overlapped by fixed finger; cutting edge with row of broad calcareous teeth and adjacent row of tufts of stiff setae, terminating in large calcareous claw; dorsal surface convex, with closely-spaced, broad spines or tubercles, showing somewhat imbricate appearance, and numerous short to long setae (some tubercles in proximal half of dactylus with capsules similar to those on palm); dorsomesial margin nearly straight, with row of moderately large, forwardly directed tubercles or spines; ventromesial face with numerous, low, broad spines and tufts of stiff setae; ventral surface with several low, squamiform tubercles and scattered tufts of moderately long stiff setae. Palm shorter than carpus; dorsomesial margin delimited by single or double row of moderately small, forwardly directed spines; dorsolateral margin with row of small spines decreasing in size proximally and row of tufts of moderately short to long plumose setae; dorsal surface convex, with sparse tufts of long setae and numerous, small, capsulate tubercles and spinules, and also with row of moderately small spines on midline of dorsal surface extending onto fixed finger; corneous, spiniform capsules weakly curved backward, arising from anterior part of tubercles, basal pores rounded or “heartshaped”; spinules and capsulate tubercles on dorsal surface of palm each with several short plumose setae arising from anterior bases; mesial face of palm flat or slightly concave, with scatter- ed low, squamiform protuberances accompanied by tufts of stiff setae; ventrolateral face (including fixed finger) with scattered low tubercles accompanied by tufts of short to moderately long setae; ventral surface with several low, broad protuberances and scattered tufts of long stiff setae. Cutting edge of fixed finger with row of large calcareous teeth, terminating in large calcareous claw. Carpus subequal in length to merus; dorsomesial margin distinctly delimited by row of moderately large spines and tufts of long setae; dorsal surface with numerous spinulose or capsulate tubercles and several moderately large spines adjacent to dorsolateral margin and with dense covering of short plumose setae; dorsolateral margin not delimited; lateral face with low, broad, sometimes multidenticulate protuberances dorsally, and small, low protuberances ventrally, all accompanied by tufts of setae, ventrolateral distal margin smooth; mesial face slightly concave, with several tufts of long plumose setae, ventromesial distal margin without row of spines; ventral surface with some spinulose tubercles and tufts of long setae distally. Merus with short transverse rows of setae on dorsal surface; dorsodistal margin unarmed but with row of dense setae; mesial face somewhat inflated ventrally in large males, not inflated in small males and females; in large males, ventromesial margin produced, unarmed or armed with few small spines proximally and with numerous long setae; in females and small males ventromesial margin not produced, armed with row of small spines and with sparse setae; lateral face with some short vertical rows of stiff setae dorsally and tufts of stiff setae ventrally, ventrolateral margin with row of small spines and numerous setae; in large males, ventral surface with scattered setae, more concave in large males than in females and small males. Ischium with tufts of short setae on all faces; ventromesial margin and ventral surface smooth. Coxa without spines on distal margin, but with tuft of long stiff setae ventromesially.

Left cheliped ( Figs 9E ; 11A, B ) reaching or slightly overreaching base of dactylus of right cheliped, weakly compressed laterally; setation generally similar to that of right. Chela elongate subovate in dorsal view, 2.90-3.30 times longer than greatest width at base of dactylus. Dactylus much longer than palm, slightly curved ventrally; cutting edge with row of small calcareous teeth in proximal 0.70-0.80 (several distal teeth interspers- ed by small corneous teeth) and with row of small corneous teeth in distal 0.20-0.30, terminating in large corneous claw; dorsal surface sloping mesially, proximally with few small spinulose tubercles. Palm about half length of carpus, triangular in cross section; dorsal surface elevated in midline but not forming distinct ridge or crest, with row of moderately large spines decreasing in size distally and extending onto proximal 0.20- 0.40 of fixed finger; dorsolateral margin with row of small spines; dorsolateral and dorsomesial surfaces strongly sloping ventrally, former surface with covering of capsulate tubercles extending to proximal half of fixed finger, and latter surface with some capsulate tubercles dorsally and also with few small spinulose tubercles; dorsomesial margin not distinctly delimited; ventrolateral face with some very low tubercles; ventral surface weakly inflated. Carpus subequal in length to merus; dorsomesial margin with row of slender spines; dorsolateral margin weakly delimited, with row of four to six small spines; dorsal surface somewhat sloping, with several capsulate tubercles and tiny tubercles; dorsodistal margin with row of tiny spines; mesial face with scattered low protuberances, distomesial margin smooth; lateral face covered with numerous low, sometimes multidenticulate protuberances, ventrolateral distal margin not strongly expanded, distally with row of small spines or tubercles. Merus without spine on dorsodistal margin; mesial face with tufts of moderately long setae dorsally, proximally and ventrally, ventromesial margin with few spinulose tubercles; lateral face ventrally with several small, low, somewhat squamous tubercles, ventrolateral margin not strongly expanded, with row of spines increasing in size distally; ventral surface weakly concave. Ischium and coxa similar to that of right cheliped.

Second and third pereopods ( Figs 8 H-K; 11C, D) similar from right to left in armature and setation. Dactyli 1.30-1.80 times as long as propodi, in dorsal view slightly twisted, in lateral view weakly curved ventrally, terminating in moderately long to long corneous claws; dactylus of right third pereopod 8.00-10.30 times as long as high in males, 7.20-9.16 times as long in females; dorsal surfaces each with tufts of short setae and row of corneous spines increasing in length distally; lateral faces each with tufts of stiff setae dorsally and ventrally and with faint median sulcus proximally; mesial faces each with rows of corneous spines, increasing in length distally and tufts of setae dorsally and ventrally; ventral margins each with nine to 12 long corneous spines, increasing in length distally. Propodi distinctly longer than carpi; dorsal surfaces each with short transverse ridges accompanied by rows of moderately short setae, often extending to lateral face, but without spine; lateral faces each with short transverse ridges accompanied by setae dorsally and sparse tufts of shorter setae ventrally; ventral surfaces each with row of widely separated tufts of setae and small corneous spines. Carpi with two moderately small spines on dorsal surfaces of second (dorsodistal spine and one spine arising posterior to midlength), only with dorsodistal spine in third; dorsal surfaces each with some tufts of moderately short plumose setae; lateral faces each with tufts of moderately long plumose setae on midline. Meri moderately broad, each with dorsal and ventral tufts of short to moderately short plumose setae; lateral faces each with few minute setae, ventrolateral distal margins unarmed. Ischium with dorsal and ventral tufts of setae. Female with paired gonopores.

Fourth pereopods ( Fig. 7D ) semichelate, similar from right to left, but left slightly shorter than right. Dactylus curved ventrally, terminating in long corneous claw, with row of fine corneous teeth on ventral margin; preungual process subequal in length to distalmost corneous spine, terminating bluntly, flexible. Propodal rasp composed of six or seven rows of corneous scales; dorsal margin of propodus with small but distinct, blunt tubercle proximally; all segments with dorsal and/or ventral tufts of long setae.

Fifth pereopod chelate; males with paired gonopores ( Fig. 7F ), each partially obscured by moderately long setae.

Third thoracic sternite with pair of minute spines on either side of shallow median notch on anterior margin. Sixth thoracic sternite with anterior lobe ( Fig. 7G ) subsemicircular, weakly to somewhat skewed to left, with numerous setae on anterior face. Eighth thoracic sternite ( Fig. 7F ) developed anteriorly as two somewhat flattened subrectangular lobes separated by shallow median depression, anterior margins each with row of setae.

Abdomen twisted. Males with four unpaired left (second to fifth) pleopods, all four unequally biramous (exopods well developed, endopods much shorter than exopod, but not rudimentary). Females also with four unpaired left pleopods, anterior three subequally biramous, fifth as in males. Uropods greatly asymmetrical; exopods and endopods both well developed rasps.

Telson ( Fig. 7H ) wider than long, with deep lateral indentations; posterior lobes slightly to somewhat asymmetrical, separated by small median cleft; terminal margins weakly oblique, each with row of five to seven closely spaced long spines and several minute to small submarginal spines; lateral margins usually dentate or spinose.

COLORATION

In life: generally light orange or tan. Shield with blotches of orange at base of rostrum either side of midline and large purple patches laterally; posterior carapace sometimes reddish. Ocular peduncle generally white, with orange band medially and with orange patch at base of cornea. Antennular peduncle generally dark orange; ultimate segment banded with white distally and basally; penultimate segment white in distal part. Antennal peduncle generally orange; fifth segment white dorsally and ventrally. Right cheliped with dark red spot on mesial face centrally; small spines on dorsal surface of palm whitish; spines, spinules and tubercles on dorsal surface of carpus dark orange; mesial surface of carpi with tinge of dark orange proximally; lateral surface of merus with L-shaped line on lateral surface distally. Color and markings of left cheliped similar to that of right, but lacking dark red spot on mesial face of palm. Dactyli of ambulatory pereopods generally dark orange, each with white patch slightly distal to midlength and red median stripe on lateral and mesial faces; propodi each with two dark orange patches, one on proximal half of dorsal surface and one at about midlength of ventral surface; lateral face with short brown longitudinal stripe distally and short obliquely transverse ridges (accompanied with setae) colored with dark red; carpi each with large orange or red spots on lateral and ventral surfaces respectively; meri each with longitudinal white stripe on lateral face adjacent to dorsal margin and with tinge of red dorsally.

SIZE

Males sl 7.7-14.7 mm; females sl 7.2-13.7 mm; ovigerous females sl 7.7-13.7 mm.

VARIATION

See Variation for P. rubrior n. sp.

REMARKS

See under P. rubrior n. sp.

Figures

FIG. 1. — Pagurus japonicus (Stimpson, 1858), sl 15.3 mm, from Kominato, Boso Peninsula (CBM-ZC 2703); A, shield and cephalic appendages, dorsal (setae omitted from left); B, left ocular acicle, dorsal; C, capsulate tubercle on dorsal surface of palm of right cheliped, lateral (setae broken); D, same, dorsal (setae omitted); E, left fourth pereopod, lateral; F, same, distal part of dactylus, lateral; G, anterior lobe of sixth thoracic sternite, ventral; H, coxae of fifth pereopod and eighth thoracic sternite, ventral; I, telson, dorsal. Scale bars: A, 5 mm; B, 1 mm; C, D, F, 0.5 mm; E, G-I, 2 mm.

FIG. 2. — Pagurus japonicus (Stimpson, 1858), sl 15.3 mm, from Kominato, Boso Peninsula (CBM-ZC 2703); A, left mandible, dorsal; B, left maxillule, ventral, inset, endopod, lateral; C, left maxilla, ventral (setae omitted); D, left first maxilliped, ventral (setae partially omitted); E, left second maxilliped, ventral (setae omitted); F, left third maxilliped, lateral; G, same, ischium, dorsal (setae partially omitted); H, left cheliped, mesial (setae omitted); I, same, lateral (setae omitted). Scale bars: A, B, G, 1 mm; C-F, 2 mm; H, I, 5 mm.

FIG. 3. — Pagurus japonicus (Stimpson, 1858),

FIG. 5. — Pagurus japonicus (Stimpson, 1858), sl 15.3 mm, from Kominato, Boso Peninsula (CBM-ZC 2703); A, right chela, dorsal (setae omitted); B, carpus of right cheliped, dorsal (setae omitted); C, left chela, dorsal (setae omitted); D, carpus of left cheliped, dorsal (setae omitted); E, left second pereopod, lateral; F, same, dactylus, mesial (setae partially omitted); G, left third pereopod, lateral (setae omitted); H, same, dactylus, mesial (setae partially omitted). Scale bars: A-E, G, 5 mm; F, H, 2 mm.

FIG. 6. — A, Pagurus similis (Ortmann, 1892), sl 11.9 mm, from off Takeoka, Boso Peninsula (CBM-ZC 1058), entire animal in dorsal view; B, Pagurus rubrior n. sp., paratype sl 14.9 mm, from Takeoka, Boso Peninsula (MNHN-Pg 6099), entire animal in dorsal view.

FIG. 7. — Pagurus similis (Ortmann, 1892), sl 9.7 mm, from off Katsuyama Ukishima Islet, Boso Peninsula (CBM-ZC 3958); A, shield and cephalic appendages, dorsal (setae partially omitted from left; left antennular peduncle mutilated); B, carapace, dorsal (setae omitted from left); C, left ocular acicle, dorsal; D, left fourth pereopod, lateral; E, same, distal part of dactylus, lateral (setae omitted); F, coxae of fifth pereopods and eighth thoracic sternite, ventral; G, anterior lobe of sixth thoracic sternite, ventral; H, telson, dorsal. Scale bars: A, D, F, H, 2 mm; B, 5 mm; C, E, G, 1 mm.

FIG. 8. — Pagurus similis (Ortmann, 1892), sl 9.7 mm, from off Katsuyama Ukishima Islet, Boso Peninsula (CBM-ZC 3958); A, left mandible, dorsal; B, left maxillule, ventral (proximal endite broken off), inset, endopod, lateral; C, left maxilla, ventral (setae omitted); D, left first maxilliped, ventral (setae omitted); E, left second maxilliped, ventral (setae partially omitted); F, left third maxilliped, lateral; G, same, ischium, dorsal (setae omitted); H, dactylus of right second pereopod, mesial (setae omitted); I, carpus of right second pereopod, mesial (setae omitted); J, dactylus and propodus of right third pereopod, lateral (setae omitted); K, dactylus of left third pereopod, mesial (setae omitted). Scale bars: A-G, 2 mm; H-K, 5 mm.

FIG. 9. — Pagurus similis (Ortmann, 1892), sl 9.7 mm, from off Katsuyama Ukishima Islet, Boso Peninsula (CBM-ZC 3958); A, chela and carpus of right cheliped, dorsal (setae omitted); B, spines and tubercles on dorsal surface of palm of right chela, dorsal; C, capsulate tubercles on dorsal surface of right chela, mesial; D, same, dorsal; E, chela and carpus of left cheliped, dorsal (setae omitted). Scale bars: A, E, 5 mm; B, 1 mm; C, D, 0.5 mm.

FIG. 10. — Pagurus similis (Ortmann, 1892), sl 9.7 mm, right cheliped, from off Katsuyama Ukishima Islet, Boso Peninsula (CBM- ZC 3958); A, mesial; B, lateral. Scale bar: 5 mm.

FIG. 11. — Pagurus similis (Ortmann, 1892), sl 9.7 mm, from off Katsuyama Ukishima Islet, Boso Peninsula (CBM-ZC 3958); A, left cheliped, mesial; B, same, lateral; C, right second pereopod, lateral; D, left third pereopod, lateral. Scale bars: 5 mm.