Paguristes versus, Komai, 2001

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 : 406-415

Paguristes versus sp. nov.

(®gures 23±27) Paguristes kagoshimensis: Kim, 1973: 214 , 597, text-®gure 44, pl. 69, ®gure 25; Miyake, 1978;

35, ®gure 12; 1982: 96, pl. 32, ®gure 5; Miyake and Imafuku, 1980a: 3; 1980b: pl. 2,

®gure 2. Not Paguristes kagoshimensis Ortmann, 1892 .

Material examined. HOLOTYPE. Okinoyama Bank , Sagami-nada, Japan, 34ss59¾N, 139ss39¾E, 105±113 m; 21.iv.1995; RV Tansei-maru, KT 95-5, stn TB18-2; dredge; male (SL 6.1 mm); CBM-ZC 1983.

PARATYPES. OOE Kochi, Tosa Bay, Shikoku, 190 m; 10 August 1991; RV Toyohatamaru, beam trawl; coll. K. Sasaki; one female (SL 4.0 mm); CBM-ZC 181. OOE Minabe, Kii Peninsula, Japan, depth unknown; 3 February 1995; gill net; coll. T. Komai; three males (SL 5.7±7.8 mm), two females (SL 2.5, 6.0 mm); CBM-ZC 862. OOE Saiki, Bungo Strait, Japan, depth unknown; 7 November 1994; commercial trawler; coll. T. Komai; two males (SL 2.5, 2.7 mm), one female (SL 1.8 mm); CBM-ZC 978. OOE Minabe, Kii Peninsula, 80±100 m; 24 March 1995; gill net; coll. T. Komai; three males (SL 6.7±7.9 mm), one female (SL 5.5 mm); CBM-ZC 1158. OOE Kochi, Tosa Bay, Japan, 110±190 m; 2 October 1989; RV Toyohata-maru, beam trawl; coll. K. Sasaki; ®ve males (SL 3.0± 5.7 mm); CBM-ZC 3025. SW of Shionomisaki, Kii Peninsula, 33ss26.13¾N, 135ss40.64¾E, 160 m; 16 January 1997; dredge; coll. S. Nagai; one male (SL 6.3 mm), one female (SL 5.3 mm); CBM-ZC 3573. OOE Kochi, Tosa Bay, 33ss17.12¾E, 133ss40.02¾E, 150±154 m; 5 March 1993; RV Toyohata-maru, beam trawl; coll. K. Sasaki; one male (SL 3.1 mm), one female (SL 1.4 mm); CBM-ZC 3853. Similar locality, 33ss16.35¾N, 133ss38.32¾E, 141±150 m; 11 November 1992; RV Toyohata-maru, beam trawl; coll. K. Sasaki; one male (SL 4.7 mm); CBM-ZC 3847. W of Matsuzaki, Suruga Bay, 195±218 m; 19 July 1979; RV Tansei-maru, KT79-11, stn 5; otter trawl; coll. E. Tsuchida; one male (SL 3.1 mm); CBM-ZC 4950. Kannonzuka-dashi, Sagami Bay, 92 m; 15 July 1958; one female (SL 4.0 mm); reported by Miyake (1978) as Paguristes kagoshimensis , det. no. 210; NSMT-CrR 1458. 5 km oOE south-west of Jogashima Islet, 100 m; 7 January 1960; one ovigerous (SL 5.9 mm); reported by Miyake (1978) as P. kagoshimensis , det. no. 372; NSMT-CrR 1756. 2 km oOE south-west of Jogashima Islet, 83 m; 26 January 1965; one male (SL 5.7 mm); reported by Miyake (1978) as P. kagoshimensi s, det. no. 575; NSMT-CrR 2305. OOE Ta-Shi, I-Lan County, NE of Taiwan, depth unknown; 31 December 1984; commercial trawler; coll. T.-Y. Chan; one male (SL 7.2 mm); NTOU.

Description. Thirteen pairs of quadriserial phyllobranchiae.

Shield (®gure 23A) 1.2±1.3 longer than broad; anterolateral margins sloping; anterior margin between rostrum and lateral projections concave; posterior margin truncate; dorsal surface with paired low elevation on gastric region and with small spines or spinules and scattered tufts of short setae laterally. Rostrum long, moderately narrow triangular, weakly curved ventrally, distinctly over-reaching lateral projections; terminating in acute spine, with fringe of sparse setae distally; dorsal surface not carinate. Lateral projections well produced, subtriangular, occasionally with small marginal spine. Branchiostegites (®gure 23C) calci®ed anteriorly and dorsally, with row of small spines on anterodorsal and distal margins.

Ocular peduncles (®gure 23A) relatively stout (3.5±4.5 times longer than width of cornea), 0.6±0.8 times as long as shield, cylindrical, not ināted basally, cornea slightly dilated; dorsal or dorsomesial surfaces with longitudinal row of tufts of long setae. Ocular acicles subtriangular, terminating in moderately strong, acute spine; margins unarmed; separated by 0.7±0.8 basal width of one acicle.

Antennular peduncles (®gure 23A, B) moderately long, over-reaching ocular peduncles by 0.3 ±0.5 length of ultimate segment. Ultimate segment moderately slender, 1.2±1.3 times longer than penultimate segment, with row of long setae on dorsal surface. Penultimate segment without ventral spine. Basal segment without spine on dorsolateral margin of statocyst lobe and laterodistal margin; ventromesial distal angle strongly produced, terminating in acute spine. Antennular ¯agellum distinctly longer than ultimate segment of peduncle.

Antennal peduncles (®gure 23A, C) moderately short, falling slightly short of base of cornea; with supernumerary segmentation. Fifth segment unarmed. Fourth segment with small spine at dorsodistal margin. Third segment with strongly produced ventromesial distal angle, terminating in strong spine. Second segment with dorsolateral distal angle well produced, terminating in simple or bi®d spine, mesial and lateral margins usually unarmed; dorsomesial distal angle with strong spine, mesial margin elevated, with numerous setae. First segment without laterodistal spine, ventromesial margin strongly produced, with one prominent spine distomesial to antennal gland opening. Antennal acicles moderately short, over-reaching midlength of ocular peduncles, terminating in simple acute spine; mesial margin with three or four moderately strong spines proximally and tufts of long stiOE setae; lateral margin with one to three spines distally. Antennal ¯agella (®gure 23D) long, 1.6±1.9 times longer than shield, reaching or slightly over-reaching tips of chelipeds, composed of about 40 articles; articles in proximal 0.3 each with several short to moderately long setae or bristles on all surfaces or margins, those in distal 0.7 with long setae every two or three articles, in addition to moderately long setae and bristles.

Endopod of maxillule (®gure 23E) slender, with one bristle on mesial margin; internal lobe strongly produced, with six bristles on rounded distal margin; external lobe well developed, elongate, strongly recurved, distolateral margin with four or ®ve setae. Third maxilliped (®gure 23F) with basis and ischium partially fused; basis with three or four denticles on dorsomesial margin; ischium (®gure 23G) with well developed crista dentata composed of slender corneous teeth, ventral margin with prominent distal spine; merus with four to six acute spines on ventral margin and one small spine on dorsodistal margin; carpus with small spine on dorsodistal margin; dactyl relatively short.

Chelipeds (®gure 24A±D) moderately short, equal or slightly subequal with left chelipeds stouter. 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 four or ®ve calcareous teeth (proximalmost one broadest) in proximal half and row of small corneous teeth in distal half, terminating in small corneous claw; overlapped by ®xed ®nger; dorsomesial margin with row of strong, conical, corneous-tipped spines decreasing in size distally in proximal half, distal half unarmed, dorsal surface with few small spinulose tubercles and scattered tufts of long stiOE setae; mesial surface with irregular double row of sparse small corneous-tipped or corneous spines and single row of 10±15 smaller corneous-tipped spines near ventral margin, and tufts of stiOE setae; ventral surface unarmed, with few tufts of stiOE setae. Palm subequal in length to carpus; dorsomesial margin with four to six strong, occasionally corneous-tipped spines, dorsal surface sloping to lateral surface without delineation of dorsolateral margin, with several irregular rows of moderately strong, conical spines decreasing in size on ®xed ®nger; mesial surface with scattered low protuberance s and tubercles, mesiodistal margin unarmed; lateral surface with scattered spinulose tubercles, low protuberances and tufts of stiOE setae; ventral surface nearly smooth, with scattered tufts of long setae. Fixed ®nger weakly to noticeably curved ventrally; cutting edge concave proximally, with row of small calcareous teeth in distal half, terminating in strong corneous claw; leaving prominent hiatus, when closed. Carpus about 0.7 times as long as merus; dorsomesial margin with row of four or ®ve strong, conical, occasionally corneous-tipped spines, increasing in size distally; dorsal surface with two irregular rows of moderately small spines or tubercles and tufts of long stiOE setae, dorsodistal margin unarmed or weakly denticulate; dorsolateral margin indicated by row of moderately small spines or tubercles; mesial surface with low protuberance s and few tufts of setae; lateral surface with scattered moderately small tubercles and low protuberances and few setae, laterodistal margin with row of submarginal small spines; ventral face unarmed. Merus moderately deep; dorsal surface with row of small spinulose tubercles accompanied by tufts of long setae and subdistal, spinulose transverse ridge, extending onto lateral and mesial faces, dorsodistal margin with row of small spines; mesial surface with scattered low protuberances dorsally and few tufts of short setae, ventromesial margin with row of small spines and sparse tufts of setae; lateral surface with denticulate protuberances and few small spinulose tubercles, ventrolateral margin with row of small spines in distal half and tufts of setae; ventral face unarmed, with few tufts of long setae. Ischium with row of small tubercles on ventromesial margin, ventrolateral distal angle unarmed. Coxa unarmed.

Second pereopods (®gure 25A, B) moderately long and slender. Dactyls long, 1.5±1.7 times longer than propodi; weakly curved in lateral view, nearly straight in dorsal view; terminating in strong, curved, corneous claw; dorsal surfaces protuberant, with few corneous-tipped spinules proximally and tufts of long setae; mesial surfaces unarmed, but with row of tufts of long setae near dorsal and ventral margins; lateral surfaces with three rows of tufts of setae; ventral margins each with row of 15±22 slender corneous spinules slightly increasing in size distally. Propodi distinctly longer than carpi; dorsal surfaces each with row of moderately strong spines mesially and tufts of long setae; mesial surfaces unarmed, but with two rows of tufts of long setae; lateral surfaces with low protuberances accompanied by tufts of setae near dorsal margin, and two rows of tufts of setae on each midline and near ventral margin; ventral surfaces slightly protuberant, unarmed, with row of tufts of long setae, ventrodistal margin unarmed. Carpi moderately long; dorsal surfaces each with single row of strong spines mesially and tufts of long setae; mesial surfaces naked; lateral faces each with tufts of stiOE setae on midline and faint longitudinal sulcus lined by row of setae; ventral surfaces with few tufts of long setae, ventrodistal margins with long setae. Meri strongly compressed laterally; dorsal surfaces slightly protuberant, with some spinules proximally and row of tufts of moderately long to long setae; mesial surfaces naked; lateral surfaces with few short setae; ventral surfaces each with row of spinules mesially and numerous long setae, both ventromesial distal and ventrolateral distal margins unarmed. Ischia with few spinules and setae on dorsal surfaces; ventral surfaces each with row of spinules mesially and numerous setae. Coxae unarmed.

Third pereopods (®gure 25C, D) generally similar to second in setation. Dactyls more strongly protuberant on dorsal surfaces than on second, accompanied by tufts of dense stiOE setae, with few tiny spinules proximally; mesial surfaces each with row of dense tufts of long stiOE setae on elevated midline and sparse tufts of setae near ventral margin; ventral margins each with 15±20 slender corneous spinules. Propodi slightly protuberant on dorsal surfaces; mesial surfaces unarmed. Carpi each with small dorsodistal spine, but dorsal surfaces lacking row of spines. Meri nearly smooth on dorsal surfaces; ventral surfaces with few tiny spinules mesially, both ventromesial distal and ventrolateral distal margins unarmed. Ischia unarmed on dorsal and ventral faces. Coxae unarmed; females with paired gonopores.

Fourth pereopods (®gure 23H) thickly setose on dorsal and ventral faces. Dactyl (®gure 23I) nearly straight, terminating in small corneous claw; dorsal surface unarmed; ventral surface with row of numerous corneous teeth laterally and tubelike preungual process arising from proximal to base of claw. Propodus moderately stout, with almost straight ventral margin; dorsal surface unarmed; propodal rasp composed of three rows of corneous scales, becoming fewer proximally, extending to 0.6 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 26A±C) with double or triple row of long setae on mesial face of basal segment. Inferior lamella strongly twisted, with distinct longitudinal ridge on ventral surface, continuous with proximolateral margin; distal margin broadly rounded, with two or three rows of moderately strong, closely set, hooked corneous spines; mesial margin with double or triple row of bristles, extending onto ventral surface proximally; lateral margin strongly sinuous. External lobe well developed, subtriangular, slightly extending as far as inferior lamella. Internal lobe moderately large, rounded, separated from basal lobe by deep U-shaped notch; mesial margin with thick, long setae.

Second pleopod (®gure 26D, E) with basal segment strongly ¯attened, with few short setae basally. Endopodite slightly twisted, margins sharply edged, with row of tufts of short setae on ventral margin and tuft of long setae at ventrodistal margin; lateral face weakly concave. Appendix masculina elongate in distal part, strongly twisted; articulation suture discernible only on interior (mesial) face; distal margin rounded; dorsal margin with dense bristles; ventral margin slightly produced at level of midlength, with tuft of long setae; exterior (lateral) face with several irregular rows of dense bristles along dorsal margin; interior (mesial) face with few long bristle near ventral margin.

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

Females with ®rst pleopods (®gure 26F) paired; articulation between basal and distal segments obscure; basal segment not ināted basally; distal segment much more slender 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, with exopod well developed, not articulated, endopod vestigial.

Brood pouch (®gure 26G) large, narrowly subtriangular, margins with thick, extremely long plumose setae. Second to fourth abdominal tergites well calci®ed on left, ®fth tergite not concealed by brood pouch, each tergite with dense, extremely long setae on left margins, obscuring pleopods (®gure 27).

Telson (®gure 23J) with posterior lobes slightly asymmetrical; each lobe subtriangular with rounded apex, separated by moderately deep median cleft, terminal and lateral margins unarmed but with long setae; lateral indentations distinct; anterior lobes unarmed on convex lateral margins.

Coloration. In life: carapace generally reddish brown dorsally, shield with pair of darker spots mesial to accessory portion; branchiostegite and lateral part white. Ocular peduncles with ventral surfaces uniformly red; dorsal surfaces reddish brown with small white spots, bordered with obscure, narrow white longitudinal stripes. Antennular peduncles cream. Antennal peduncles with tinge of reddish brown; ¯agella uniformly pale reddish brown. Chelipeds generally reddish brown, spines and protuberance s white, appearing as scattered white spots. Ambulatory pereopods reddish brown, each with tinge of darker red around articulations between dactylpropodus, propodus-carpu s and carpus-merus; propodi, carpi and meri with complex pattern of white, surfaces rugose appearance.

Size. Largest male: SL 7.2 mm; largest female: SL 6.0 mm; ovigerous female: 5.9 mm.

Habitat and symbiotic association. Gastropod shells.

Distribution. Paci®c coast of Japan, from Boso Peninsula to Ohsumi Islands; Korea; north-east coast of Taiwan.

Etymology. The speci®c epithet is a noun in apposition from the Latin, versus, meaning row, in reference to the characteristic ventral row of spines on the mesial surfaces of the dactyl of the cheliped.

Remarks. Although this new species has been misidenti®ed as Paguristes kagoshimensis (5 P. digitalis) by previous authors ( Kim, 1973; Miyake, 1978; 1982; Miyake and Imafuku, 1980a, 1980b), it is quite diOEerent from the latter. The absence of spines on the terminal margins of the telson provides evidence that the species should be placed in group B of the genus, not group A (cf. McLaughlin and Provenzano, 1974b). The new species appears close to P. palythophilus and P. albimaculatus sp. nov. In these three species, the gills are quadriserial phyllobranchiae. The presence of a clearly formed ventral row of small spines and fewer scattered spines on the mesial surface of the dactyl of the cheliped separates P. versus from the two close relatives. The ®ne, extremely long, dense setae on the second to ®fth abdominal tergites of females is also characteristic of the new species. A similar condition is known only in P. lauriei McLaughlin and Hogarth, 1998 , but the latter species was said to lack the brood pouch.

Six specimens referred to P. kagoshimensis by Miyake (1978) (NSMT-CrR1458; 1756; 489; 509; 525; 575) have been re-examined and three (NSMT-CrR 1458, Miyake det. no. 210; CrR 1756, Miyake det. no. 372; and CrR 2305, Miyake det. no. 575) found to represent P. versus (see Remarks under P. digitalis ). Illustrations and photographs of P. kagoshimensis given by Kim (1973: text-®gure 44; pl. 69, ®gure 25a,b) agree most closely with the new species. Miyake and Imafuku (1980a) and Miyake (1982) mentioned the presence of a distinct ventral row of spines on the mesial face of the dactyl of the cheliped, and therefore these records are referred to the new species with con®dence. Judging from the colour photographs, the specimens identi®ed as P. kagoshimensis by Baba (1986) and Yu and Foo (1990) should be referred to P. albimaculatus sp. nov.