Paguristes digitalis Stimpson, 1858

Komai, 2001, review of the north-western Paci ® c species of the genus Paguristes Decapoda: Anomura: Diogenidae), I. Five species initially reported Ortmann (1892) from Japan, Journal of Natural History 35 (3), pp. 357-428 : 396-406

Paguristes digitalis Stimpson, 1858

(®gures 1B, 19±22)

Paguristes digitalis Stimpson, 1858: 247 ; 1907: 212, pl. 25, ®gure 1; Alcock, 1905: 155 (bibliography); Balss, 1913: 37, ®gures 26, 27; Terao, 1913: 374; Yokoya, 1933: 73; Makarov, 1938: 166, ®gure 66; 1962: 156, ®gure 66; Yokoya, 1939: 280; Kamita, 1955: 30, ®gure 10; Gordan, 1956: 322 (bibliography); Miyake, 1957: 86; Miyake et al., 1962: 125 (list); Miyake, 1965: 640, ®gure 1066; 1978: 29, ®gure 9; Miyake and Imafuku, 1980a: 3; Miyake, 1982: 97, pl. 33, ®gure 2; Komai et al., 1992: 196; Takeda, 1994: 225, ®gure 7.

Paguristes kagoshimensis Ortmann, 1892: 281 , pl. 12, ®gure 8; Alcock, 1905: 155 (bibliography); Gordan, 1956: 322 (bibliography).

Paguristes barbatus: Doēin, 1902: 645 (in part).

Not Paguristes digitalis: Igarashi, 1970 : pl. 2, ®gure 4. [5 Paguristes ortmanni Miyake, 1978 ].

Not Paguristes kagoshimensis: Balss, 1913: 40 . [5 Paguristes doederleini sp. nov.].

?Not Paguristes kagoshimensis: Yokoya, 1933: 75 ; Miyake et al., 1962: 125. See Remarks.

Not Paguristes kagoshimensis: Kim, 1973: 214 , 597, text-®gure 44, pl. 69, ®gure 25; Miyake, 1978: ®gure 12; 1982: 96, pl. 32, ®gure 5; Miyake and Imafuku, 1980a: 3; 1980b: pl. 2, ®gure 2. [5 Paguristes versus sp. nov.]

Not Paguristes kagoshimensis: Miyake, 1978: 35 . [Four species are mixed: P. palythophilus Ortmann, 1892 ; P. acanthomerus Ortmann, 1892 ; Paguristes versus sp. nov.; and Paguristes sp. ].

Not Paguristes kagoshimensis: Baba, 1986: 191 , 298, ®gure 139; Yu and Foo, 1990: 52, unnumbered ®gure [5 Paguristes albimaculatus sp. nov.].

Material examined. OOE Choshi, Chiba, central Japan, depth unknown; 11 September 1990; commercial trawler; coll. T. Komai; one ovigerous female (SL 11.5 mm); CBM-ZC 3. OOE Takeoka, Uchibo coast of Boso Peninsula, 30±40 m; 9 May 1994; gill net; coll. T. Komai; ®ve males (SL 7.1±10.0 mm); CBM-ZC 430. OOE Takeoka, Uchibo Coast of Boso Peninsula, 10±20 m; 29 August 1994; gill net; coll. T. Komai; one male (SL 8.0 mm), one female (SL 7.7 mm); CBM-ZC 606. Kushimoto, Kii Peninsula, depth unknown; reared in aquarium; gill net; coll. K. Nomura; one male (SL 8.0 mm), one ovigerous female (SL 7.1 mm); CBM-ZC 1039. SE of Katsuyama Ukishima Islet, Uchibo coast of Boso Peninsula, 140±220 m; 10 May 1995; gill net; coll. T. Komai and M. Miya; one female (SL 5.5 mm); CBM-ZC 1666. Miyako Bay, Iwate, north-easter n Honshu, 15±20 m; 24.v.1995; gill net; coll. T. Komai; one female (SL 11.8 mm); CBM-ZC 1681. Funakoshi Bay, Iwate, 39ss23,634¾N, 141ss57,191¾E, 66 m; 25 May 1995; dredge; coll. T. Komai; one male (SL 9.7 mm); CBM-ZC 1910. Same locality, 39ss23.113¾N, 141ss58.493¾E, 50 m; 25 May 1995; dredge; coll. T. Komai; one male (SL 10.7 mm); CBM-ZC 1928. Hakodate Bay, southern Hokkaido, 10±20 m; 17 March 1995; gill net; coll. T. Komai; two males (SL 12.7, 13.7 mm), two females (SL 8.7, 10.0 mm); topotypic material; CBM-ZC 2364. Kagoshima, Kyushu, 72±90 m; 1880; coll. L. DoÈderlein; two males (SL 4.3, 4.8 mm); larger one is here selected as the lectotype of Paguristes kagoshimensis Ortmann, 1892 , and therefore the smaller one is paralectotype; MZS 347 (spirit). Maizuru, Sea of Japan, 63±72 m; 1881; coll. L. DoÈderlein; two specimens (sex not determined and size not measured because of dry condition), paralectotypes of Paguristes kagoshimensis ; MZS 72 (dry) Ito, Sagami Bay; 1± 12 March 1903; coll. A. Haberer; one male (SL 11.4 mm), one ovigerous female (SL 4.5 mm); reported by Balss (1913), No. 1903/8911; ZSM 231/1. Shuragane, oOE Hayama, Sagami Bay, 30±40 m; 2 February 1955; one male, fragmented; reported by Miyake (1978), det. no. 106; NSMT-CrR 913. OOE Hayama, Sagami Bay; 10 February 1959; trawl; one male (SL 4.4 mm); reported by Miyake (1978), det. no. 239; NSMT-CrR 1529. Similar locality; 12 December 1959; bottle trap for octopus; one female (SL 5.8 mm); reported by Miyake (1978), det. no. 266; NSMT-CrR 1561. Similar locality; 24 July 1959; bottle trap for octopus; one male (SL 7.5 mm), one ovigerous (SL 9.1 mm); reported by Miyake (1978), det. no. 290; NSMT-CrR 1609. Between Shuragane and Kakine, Sagami Bay. 20±35 m; 5 February 1964; one male (SL 5.5 mm); reported by Miyake (1978), det. no. 532; NSMT-CrR 2188. 2.5 km oOE westnorth-by-west of Jogashima Islet, 65±75 m; 13 February 1965; one female (SL 6.1 mm); reported by Miyake (1978), det. no. 587; NSMT-CrR 2322. West of Kamegisho, Sagami Bay, 80±100 m; 21 February 1966; one male (SL 9.2 mm); reported by Miyake (1978), det. no. 605; NSMT-CrR 2389.

Description. Thirteen pairs of biserial phyllobranchiae (®gure 1B).

Shield (®gure 19A) 1.2±1.4 times longer than broad; anterolateral margins sloping; anterior margin between rostrum and lateral projections concave; posterior margin truncate; dorsal surface rugose, with low elevations on either side of midline and numerous small spines or spinules marginally and laterally and tufts of short to moderately long setae. Rostrum relatively long, moderately narrowly triangular, weakly curved ventrally or nearly straight, distinctly over-reaching lateral projections; terminating in acute spine, with sparse setae distally; dorsal surface broadly carinate posteriorly; lateral margins variable from smooth to denticulate (®gure 19A, B). Lateral projections obtusely triangular, occasionally with small marginal spine. Branchiostegites (®gure 19D) calci®ed anteriorly and dorsally, margins unarmed.

Ocular peduncles (®gure 19A) slender (7.0 ±9.1 times longer than width of cornea), 0.7±0.8 times as long as shield, cylindrical, noticeably ināted basally, cornea not dilated; dorsal or dorsomesial surfaces each with longitudinal row of tufts of long setae. Ocular acicles subtriangular, terminating in acute spine; mesial margins unarmed or armed with one small spine, lateral margins unarmed or armed with one to four small spines (®gure 19A, B); separated by 0.5±0.7 of basal width of one acicle.

Antennular peduncles (®gure 19A, C) when fully extended over-reaching distal margins of corneas by 0.1±0.3 length of ultimate segment. Ultimate segment slender, about 1.8 times longer than penultimate segment, with row of long setae on dorsal surface, unarmed. Penultimate segment without ventral spine. Basal segment with spine on dorsolateral margin of statocyst lobe, laterodistal margin with spinule, ventromesial distal angle produced, terminating in acute spine. Antennular ¯agellum distinctly shorter than ultimate segment of peduncle.

Antennal peduncles (®gure 19A, D) moderately short, usually reaching distal 0.6±0.7 length of ocular peduncle by distal margin of ®fth segment; with supernumerary segmentation. Fifth segment unarmed. Fourth segment with small spine at dorsodistal margin. Third segment with strong ventrodistal spine, mesial face with tufts of setae. Second segment with dorsolateral distal angle weakly produced, terminating in strong simple or bi®d spine, lateral margin with one to four spinules and tufts of long setae, mesial margin unarmed; dorsomesial distal angle with small spine, partially obscured by long setae. First segment with one to three spinules on laterodistal margin, lateral face with few scattered spinules; ventromesial margin strongly produced, armed with one spine on either side of antennal gland opening. Antennal acicles moderately long, usually reaching distal 0.7 of ®fth segment, terminating in strong simple or bi®d spine; ināted basally; mesial margin with row of three to ®ve strong spines, predominantly on proximal half and obscured by long setae, lateral margin unarmed or with one to three small to strong spines. Antennal ¯agella (®gure 19E) 1.4±1.5 times longer than shield, usually not exceeding tips of chelipeds, composed of more than 40 articles; each article with very long setae distally.

Endopod of maxillule (®gure 19F) broad, without bristle on mesial margin; internal lobe distinctly produced, with four bristles on rounded distal margin; external lobe very well developed, elongate, strongly recurved, distolateral corner with four setae. Third maxilliped (®gure 19G) with basis and ischium partially fused; ischium (®gure 19H) with well developed crista dentata composed of moderately slender corneous teeth, ventral margin and dorsolateral corner unarmed; merus with three to ®ve small spines or tubercles on ventral margin and one small spine on dorsodistal margin; carpus with small spine at dorsodistal margin; dactyl moderately long.

Chelipeds (®gure 20A±D) moderately short, subequal with left cheliped slightly larger; armature generally similar. Chela subovate in dorsal view, 2.0±2.5 times longer than wide. Dactyl 1.3±1.5 times longer than palm; cutting edge with row of small calcareous teeth in proximal half and row of large corneous teeth in distal half, terminating in strong corneous claw; slightly overlapped by ®xed ®nger; dorsomesial margin with row of strong, corneous-tipped spines and tufts of stiOE setae, dorsal surface with two somewhat irregular rows of strong, corneous-tipped spines and tufts of stiOE setae; mesial surface with few moderately small spines proximodorsally and ®ve to seven oblique rows of small corneous-tipped or corneous spines; ventral surface unarmed, with tufts of stiOE setae. Palm shorter than carpus; dorsomesial margin with four or ®ve strong, corneous-tipped spines, dorsal surface with several irregular rows of prominent, usually corneous-tipped spines, decreasing in size on ®xed ®nger, and tufts of long setae; dorsolateral margin with strong, corneoustipped spines increasing in size on ®xed ®nger; lateral and ventral surfaces with scattered moderately small, corneous-tipped spines and tufts of setae; mesial surface with few low protuberances accompanied by setae, mesiodistal margin denticulate. Fixed ®nger nearly straight or slightly curved ventrally; cutting edge with row of strong calcareous teeth in proximal 0.5 and row of moderately strong corneous teeth in distal 0.5, terminating in strong corneous claw; without hiatus when closed. Carpus about 0.7 times as long as merus; dorsomesial margin with row of four or ®ve strong, conical, usually corneous-tipped spines, increasing in size distally; dorsal surface sloping to lateral surface without delineation of dorsolateral margin, with three or four irregular rows of small to moderately large, usually corneous-tipped spines and tufts of long stiOE setae, dorsodistal margin with row of small spines; lateral surface with scattered small to moderately strong spines and few tufts of setae, laterodistal margin with few small spines; mesial surface with few small spinulose tubercles near dorsal margin and tufts of setae, mesiodistal margin nearly smooth; ventral face unarmed, with few setae. Merus deep; dorsal surface with spinulose transverse ridges accompanied by tufts of long setae, distalmost ridge strongly spinulose, extending to lateral and mesial faces, dorsodistal margin with row of small spines; lateral surface spinulose, ventrolateral margin sinuous, with row of small spines and tufts of long setae; mesial surface nearly smooth, with few tufts of short setae dorsally, ventromesial margin with row of small to large spines and tufts of long setae; ventral surface unarmed, with few tufts of long setae. Ischium with row of small acute spines on ventromesial margin, ventrolateral distal margin with few small tubercles. Coxa minutely denticulate on ventrolateral margin, margins setose.

Second pereopods (®gure 21A, B) moderately long. Dactyls long, 1.5±1.7 times longer than propodi; weakly curved in lateral view, nearly straight or slightly twisted in dorsal view; terminating in strong, curved, corneous claws; dorsal surfaces each with row of prominent, often conical or tubular, corneous-tipped spines proximally, and row of strong corneous spines distally, each partially obscured by numerous tufts of long setae; mesial faces faintly sulcate proximally, each with single row of eight to ten small corneous spines ventrally and two rows of tufts of setae dorsally and ventrally; lateral faces faintly sulcate proximally, each with row of tufts of setae on midline and row of small corneous spines near ventral margin, accompanied tufts of stiOE setae; ventral surfaces each with row of 15±18 moderately small corneous spines, increasing in size distally, ¯anked by two rows of tufts of long stiOE setae. Propodi distinctly longer than carpi; dorsal surfaces each with row of strong, corneous-tipped spines mesially, partially obscured by tufts of long setae, dorsodistal margins denticulate; mesial surfaces with scattered small tubercles and numerous tufts of long stiOE setae; lateral surfaces each with row of low protuberances near dorsal margin, row of small tubercles near ventral margin and tufts of stiOE setae on midline; ventral surfaces each with row of protuberances bearing corneous spinules and tufts of long setae, ventrodistal margins each with row of small corneous spines or spinules. Carpi moderately long; dorsal surfaces each with double row of strong, corneous-tipped spines mesially and tufts of long setae; mesial surfaces with small tubercles and tufts of setae dorsally, mesiodistal margins with spinules; lateral faces strongly convex, each with shallow longitudinal sulcus lined with tufts of stiOE setae and additional submedian row of low protuberances accompanied by one or two corneous spinules and row of stiOE setae; ventral surfaces with few tufts of setae, ventrodistal margins with long setae. Meri strongly compressed laterally; dorsal surfaces each with row of spinules laterally and numerous setae; mesial surfaces with small tubercles and short transverse rows of long setae dorsally and scattered setae ventrally; lateral surfaces with few tufts of setae near dorsal margins and scattered very short setae; ventral surfaces each with double row of small spines and numerous long setae, ventromesial margins without subdistal spine, ventrolateral margins protuberant, sometimes with small subdistal spine. Ischia with spinule and numerous setae on dorsal surfaces; ventral surfaces with row of spinules mesially and numerous setae. Coxae sometimes with row of small tubercles on laterodistal margin.

Third pereopods (®gure 21C, D) generally similar to second in setation. Dactyls each with single or double row of corneous spines on dorsal surface (proximal two or three spines corneous-tipped); lateral surfaces each with row of tufts of stiOE setae on midline; mesial surfaces each with single row of moderately strong corneous spines, ¯anked by two rows of tufts of setae; lateral surfaces with row of tufts of setae on midline and near ventral margin; ventral surfaces each with row of 12±18 moderately strong corneous spines mesially, increasing in size distally. Propodi protuberant on dorsal surfaces, with few small corneous spines distally; mesial surfaces each with row of strong, corneous-tipped spines dorsal to midline and double row of protuberances, sometimes bearing small corneous spines, ventral to midline, mesiodistal margins with one or two corneous spinules; ventral surfaces protuberant, with few small corneous spines. Carpi with double row of small spines on dorsal surfaces; mesial faces with few tufts of stiOE setae; lateral surfaces with few low protuberances accompanied by row of stiOE setae ventral to faint longitudinal sulcus. Meri each with double row of spinules on dorsal surfaces; mesial surfaces with few small tubercles dorsodistally; lateral surfaces with few tufts of short setae; ventral surfaces each with row of small spines or spinulose tubercles mesially and few tiny tubercles laterally, ventrolateral margins tuberculate distally, ventromesial margins smooth. Coxae usually with row of tubercles on each laterodistal margin; females with paired gonopores.

Fourth pereopods (®gure 19I), thickly setose on dorsal and ventral faces. Dactyl (®gure 19J) slightly curved, terminating in strong corneous claw; dorsal surface usually with one corneous spine somewhat distal to midlength; ventral surface with row of four to six corneous teeth laterally and tube-like preungual process arising from base of distal corneous tooth. Propodus relatively stout, with weakly convex ventral margin; dorsal surface unarmed; propodal rasp composed of four or ®ve rows of small corneous scales, becoming fewer rows proximally, extending to 0.7 length of ventral margin. Carpus without dorsodistal spine.

Fifth pereopods chelate, setose. Coxae in males each with gonopore.

First and second pleopods in males paired, modi®ed. First pleopod (®gure 22A±C) with double or triple row of long setae on mesial face of basal segment. Inferior lamella strongly twisted, with blunt longitudinal ridge on ventral surface, continuous with proximolateral margin; distal margin broadly rounded, with single row of moderately strong, hooked corneous spines; mesial margin with numerous bristles, extending onto ventral surface proximally; lateral margin strongly sinuous. External lobe well developed, rounded, slightly over-reaching inferior lamella. Internal lobe moderately large, rounded, separated from external lobe by prominent notch; mesial margin with thick, long setae.

Second pleopod (®gure 20D, E) with basal segment somewhat ¯attened, lacking setae. Endopodite ¯attened, slightly twisted, margins blunt-edged, with tufts of long stiOE setae on mesial margin; lateral margin lacking setae; tuft of stiOE setae at ventrodistal angle. Appendix masculina slender, slightly twisted, not noticeably elongate distally; articulation suture clearly discernible on every face; distal margin rounded; exterior (lateral) surface faintly sulcate, with numerous short to long bristles dorsally and distally; ventral margin nearly straight, without bristles or setae in proximal 0.8; interior (mesial) face sulcate, with bristles distally and dorsally.

Third to ®fth pleopods in males unpaired, exopods very well developed, endopods rudimentary.

Females with ®rst pleopods (®gure 22F) paired; articulation between basal and distal segments obscure; basal segment slightly ināted basally; distal segment slightly narrower and longer than basal segment. Second to ®fth pleopods unpaired; second to fourth pleopods with both rami well developed, exopods much longer than endopods, multiarticulated, endopod incompletely biarticulated; ®fth pleopod much shorter than preceding pleopods, with exopod well developed, not articulated, endopod vestigial.

Brood pouch (®gure 22G) large, subrectangular, margins not indented, with thick, short to long plumose setae. Second to fourth abdominal tergite somewhat calci®ed on left, with moderately long setae on left margin.

Uropods strongly asymmetrical; protopods with two or three rows of corneous spinules on lateral margins.

Telson (®gure 19K) with posterior lobes somewhat asymmetrical, left larger than right; subquadrat e or rounded; separate d by narrow median cleft; transverse indentation deep; right terminal and lateral margins with four to eight strong spines and row of long setae; left terminal and lateral margins with eight to 12 strong, sometimes corneous-tipped spines increasing in size laterally. Anterior lobes with two or three prominent spines and row of long setae on lateral margins.

Coloration. In life: entire animal brown generally. Shield with pair of dark brown blotches posteriorly. Ocular peduncles with dark reddish brown median stripe on white background; basal part of ocular acicles white. Antennular peduncles white, with dark reddish brown longitudinal stripe on distal segments of peduncle. Fifth segment of antennal peduncle with longitudinal stripe of dark reddish brown dorsolaterally, remaining part whitish. Meri of ambulatory pereopods with tinge of white on lateral surfaces ventrally.

Variation. This species exhibits considerable variations in the armature of the rostrum and ocular acicles. The margins of the rostrum are entire (®gure 19A) or sometimes minutely denticulate (®gure 19B). The ocular acicles can be simple (®gure 19A) or have two or more marginal small spines (®gure 19B).

Size. Largest male: SL 13. 7 mm; largest female: SL 11.5 mm; ovigerous females: SL 4.5±9.1 mm.

Habitat. Gastropod shells.

Distribution. Japan, southern Hokkaido to Kyushu; Korea; subtidal to 220 m.

Remarks. Stimpson (1858) based his description of Paguristes digitalis presumably on a single specimen (sex was not indicated). It was destroyed in the great ®re of Chicago in 1871 (see Evans, 1967). The type locality was Hakodate, southern Hokkaido, Japan. The material examined in this study contains four topotypic specimens.

The presence of a series of spines on the terminal margins of the telson provides evidence that Paguristes digitalis should be placed in group A of the genus (cf. McLaughlin and Provenzano, 1974b), and the presence of ®ve to seven oblique rows of corneous-tipped spinules on the mesial surfaces of the cheliped dactyls, giving a rasp-like appearance, mentioned in the brief original description of Stimpson, immediately separates this species from the other known members of the genus.

The type material of Paguristes kagoshimensis , deposited in the MuseÂe Zoologique, Strasbourg, consists of four specimens, two from Kagoshima, Kyushu, and two from Maizuru, the Sea of Japan coast of mainland Honshu. Ortmann (1892) did not designate a holotype, and therefore the four specimens are syntypes. A re-examination of these specimens has disclosed that Paguristes kagoshimensis is actually conspeci®c with Paguristes digitalis , and quite diOEerent from the species heretofore assigned to Paguristes kagoshimensis by subsequent authors ( Balss, 1913; Yokoya, 1933; Miyake et al., 1962; Kim, 1973; Miyake, 1978, 1982; Miyake and Imafuku, 1980a,b; Baba, 1986; Yu and Foo, 1990). Ortmann’s (1892) original description of Paguristes kagoshimensis consisted of a simple description and diagrammatic ®gure of the carapace and cephalic appendages, therefore, it is not surprising that subsequent authors did not correctly identify this taxon. I have found that the specimen reported by Balss (1913) as P. kagoshimensis actually represents P. doederleini sp. nov. Six of the seven specimens referred to P. kagoshimensis by Miyake (1978) (NSMT-CrR1458; 1756; 489; 509; 525; 575) have been re-examined and it has been found that none of them represent P. digitalis . The three specimens (NSMT-CrR 1458, Miyake det. no. 210; CrR 1756, Miyake det. no. 372; and CrR 2305, Miyake det. no. 575) are designated as paratypes of P. versus ; the male specimen (NSMT-CrR 2115, Miyake det. no. 509) belongs to P. palythophilus ; the female specimen (NSMT-CrR 2161, Miyake det. no. 525) is P. acanthomerus ; and the male specimen (SL 9.9 mm; NSMT-CrR 2067, Miyake det. no. 489) represents an undescribed species, which is similar to P. doederleini described below. The undescribed species will be named in a separate paper.

The reports of Paguristes kagoshimensis by Kim (1973) from Korea, Miyake (1982) and Miyake and Imafuku (1980a, 1980b) from Japanese waters are referable with con®dence to Paguristes versus sp. nov., as the authors all provided descriptions and/or illustrations of their specimens (see Remarks under P. versus sp. nov.). Judging from the colour photographs published by Baba (1986) and Yu and Foo (1990), they were actually reporting P. albimaculatus sp. nov. under the name of P. kagoshimensis . Yokoya (1933) reported P. kagoshimensis from several Japanese localities but provided only a reference to Ortmann’s description and ®gure. Miyake (1961) included P. kagoshimensis in the list of decapods from Amakusa, western Kyushu; however, as neither these specimens, nor those upon which Yokoya (1933) based his report, have been available for re-examination, their references have been included in the synonymy questionably.

Citation of Paguristes kagoshimensis of Alcock (1905) and Gordan (1956) were merely bibliographic references. Doēin (1902) suggested that P. kagoshimensis was conspeci®c with P. barbatus sensu Ortmann, 1892 , but it seems that he had no personal knowledge of the latter species. Terao (1913) correctly interpreted P. kagoshimensis as a junior synonym of P. digitalis , but he gave no justi®cation. Consequently subsequent authors did not accept or follow Terao’s (1913) synonymy.

Judging from the photograph, Igarashi’ s (1970) specimen identi®ed as P. digitalis actually represented P. ortmanni , as the colour markings of the ocular peduncles agree better with those of P. ortmanni , rather than those of P. digitalis .