Pagurixus carinimanus, Komai & Osawa, 2006

Komai, Tomoyuki & Osawa, Masayuki, 2006, A review of the Pagurixus boninensis species group, with descriptions of six new species (Crustacea: Decapoda: Anomura: Paguridae), Zootaxa 1214 (1), pp. 1-107 : 7-10

Key to species of the Pagurixus boninensis group

Adult males

1 Palm of right cheliped with clearly delimited dorsomesial margin; third pereopods dissimilar, left appreciably broader than righ .................................... P. carinimanus n. sp.

­ Palm of right cheliped with dorsomesial margin not delimited; third pereopods generally similar from right to left......................................................................................... 2

2 Carpus of left cheliped with lateral face divided into oblique dorsal and perpendicular ventral sections by weak longitudinal ridge.................................................................. 3

­ Carpus of left cheliped with lateral face nearly perpendicular, without longitudinal ridge............................................................................................................................... 8

3 Carpus of right cheliped unarmed; carpus of left cheliped with small tubercles or protuberances on dorsolateral and dorsomesial margins but without conspicuous spines [carpus of left cheliped 2.5 or less as long as distal width; dactyli of ambulatory legs slender, 7.1–8.2 times longer than broad; anterior lobe of sixth thoracic somite with rounded anterolateral angles] ........................................... .................. P. concolor n. sp.

­ Carpi of chelipeds armed with conspicuous spines on dorsal surfaces......................... 4

4 Dactyli of ambulatory legs 5.0–7.0 times longer than high; carpus of left cheliped 2.3–2.7 times longer than distal width; meri of third pereopods with ventrolateral distal spine ......................................................................................... ............................... 5

­ Dactyli of ambulatory legs 8.4–10.5 times longer than high; carpus of left cheliped 2.8–4.8 times longer than distal width; meri of third pereopod unarmed on ventrolateral distal margin....................................................................................... ................... 6

5 Carpus of right cheliped with dorsolateral row of moderately large spines; merus of right cheliped with row of spines on ventrolateral margin; merus of left cheliped armed with row of conspicuous spines on ventrolateral margin ............... P. laevimanus

­ Carpus of right cheliped without conspicuous spines on dorsal surface laterally; merus of right cheliped with 1 or 2 spines followed by row of small tubercles on ventrolateral margin; merus of left cheliped without conspicuous spines on ventrolateral margin ..... ........................................................................................................................ P. tweediei

6 Ocular peduncle relatively slender, corneal width 0.3 of peduncular length; anterior lobe of sixth thoracic sternite oval .................................................................. P. pulcher

­ Ocular peduncle stout, corneal width 0.4–0.5 of ocular peduncular length; anterior lobe of sixth thoracic sternite subrectangular or transversely oblong ........................... 7

7 Ultimate segment of antennular peduncle with 1 or 2 short setae at dorsolateral distal angle and with 2 rows of sparse, relatively long setae on ventral surface; carpus of left cheliped with row of conspicuous spines on dorsolateral and dorsomesial margins; anterior lobe of sixth thoracic sternite subrectangular with anterolateral angles rounded; telson with 3–5 large spines on each terminal margin ..................... P. maorus

­ Ultimate segment of antennular peduncle with tuft of long setae at dorsolateral distal angle and with 2 setal rows on ventral surface, each consisting of irregular longitudinal rows of dense short setae; carpus of left cheliped without conspicuous spines on dorsolateral and dorsomesial margins; anterior lobe of sixth thoracic sternite transversely oblong, with anterolateral angles laterally produced; telson with 5–7 very small spines on each terminal margin ............................................................ P. nomurai

8 Dactyli of ambulatory legs 3.0–4.1 times longer than broad ( Figs. 28C, D , 39C, D )... 9

­ Dactyli of ambulatory legs 4.8–7.1 times longer than broad ( Figs. 22B, D , 25F–H , 35C, D , 43F, G ) ............................................................................................... ........... 10

9 Shield approximately as long as broad; carpus of left cheliped with row of low protuberances on dorsomesial margin; coxa of right fifth pereopod without ventromesial protrusion ................................................................................ P. brachydactylus n. sp.

­ Shield distinctly longer than broad; carpus of left cheliped with row of spines on dorsomesial margin; coxa of right fifth pereopod with prominent ventromesial protrusion ...................................................................................................... P. pseliophorus n. sp.

10 Left gonopore fully developed ................................................................................... 11

­ Left gonopore absent or very small if presen............................................................. 12

11 Ultimate segment of antennular peduncle with 2 rows of tufts of short setae on ventral surface ( Fig. 19C ); carpus of right cheliped with row of spines at least on dorsomesial margin; right coxa of fifth pereopod with prominent ventromesial protrusion............... ........................................................................................... ........................ P. boninensis

­ Ultimate segment of antennular peduncle with 2 rows of short setae, each row consisting of short obliquely transverse rows of very short setae ( Fig. 23C, D ); carpus of right cheliped without conspicuous spines; right coxa of fifth pereopod without ventromesial protrusion.................................................................................... ............. P. festinus

12 Ultimate segment of antennular peduncle with 2 rows of short setae of unequal length, not forming distinct tufts ( Fig. 33C ); right palm covered with spinulose granules; right coxa of fifth pereopod with prominent ventromesial protrusion and with long setae reaching to left coxa ( Fig. 33G ) ............................................................ P. paulayi n. sp.

­ Ultimate segment of antennular peduncle with 2 rows of tufts of short setae ( Fig. 40C ); right palm covered with fine, non­spinulose granules; right coxa of fifth pereopod without prominent ventromesial protrusion and with short setae not reaching left coxa ( Fig. 40H ). ...................................................................................... P. ruber n. sp.

Adult females

1 Left chela with sharply carinate dorsomesial margin and 2 keels on dorsal surface; third pereopods dissimilar, left appreciably broader than right ..... P. carinimanus n. sp.

­ Left chela with dorsomesial margin not delimited, dorsal surface devoid of keels; third pereopods similar from right to left. ............................. ............................................... 2

2 Carpus of left cheliped with distinct longitudinal ridge on lateral face ....................... 3

­ Carpus of left cheliped without longitudinal ridges on lateral face. .......................... .. 7

3 Carpus of right and left chelipeds without conspicuous spines on dorsal surface; [anterior lobe of sixth thoracic somite with rounded anterolateral angles] P. concolor n. sp.

­ Carpus of right cheliped with row of small to moderately large spines at least on dorsomesial margin............................................................................ ................................ 4

4 Ocular peduncle relatively slender, corneal width 0.3 of peduncular length; anterior lobe of sixth thoracic sternite oval. .............................................................. .. P. pulcher

­ Ocular peduncle stout, corneal width 0.4–0.5 of peduncular length; anterior lobe of sixth thoracic sternite subrectangular or transversely oblong ....................................... 5

5 Ultimate segment of antennular peduncle with 1 or 2 short setae at dorsolateral distal angle and 2 rows of relatively long setae on ventral surface; Anterior lobe of sixth thoracic sternite with anterolateral angles rounded; telson with 3–5 large spines on each terminal margin ......................................................................................... ..... P. maorus

­ Ultimate segment of antennular peduncle with tuft of long setae at dorsolateral distal angle and with 2 setal rows on ventral surface, each consisting of irregular longitudinal rows or short transverse rows of very short setae; anterior lobe of sixth thoracic sternite with anterolateral angles produced laterally; telson armed with 5–7 very small spines on each terminal margin .............................. ...................................................... 6

6 Carpus of left cheliped 2.3–2.5 times longer than distal width; dactyli of ambulatory legs 5.0–7.0 times longer than broad. ........................................................... P. tweediei

­ Carpus of left cheliped 3.0–4.3 longer than distal width; dactyli of ambulatory legs 9.0–11.0 times longer than broad .................................................................. P. nomurai

7 Ultimate segment of antennular peduncle with 2 setal rows on ventral surface each consisting of dense or closely set short setae ................................. .............................. 8

­ Ultimate segment of antennular peduncle with 2 rows of equidistantly spaced tufts of setae on ventral surface. ........................................... ................................................... 9

8 Carpus of left cheliped without conspicuous spines on dorsal surface; dactyli of second pereopods slender, more than 4.5 times longer than broad...................... P. festinus

­ Carpus of left cheliped with row of spines on dorsomesial margin; dactyli of second pereopods stout, less than 4.5 times longer than broad................ P. pseliophorus n. sp.

9 Merus of left cheliped with row of small spines on ventrolateral margin distally.......... .................................................................................................................... P. boninensis

­ Merus of left cheliped with 1 or 2 small subdistal spines and small protuberances on ventrodistal margin........ .......................................................................... P. ruber n. sp.

Figures

FIGURE 19. Pagurixus boninensis (Melin, 1939). A–F, male (SL 2.2 mm) from Chichi­jima Island, Ogasawara Islands (CBM­ZC 8472); G–I, male (SL 2.3 mm) from Chichi­jima Island, Ogasawara Islands (CBM­ZC 8474). A, shield and cephalic appendages, dorsal view (setae omitted from right side); B, ultimate segment of left antennular peduncle, lateral view; C, same, ventral view; D, sixth thoracic sternite, ventral view; E, coxae of fifth pereopods and eighth thoracic sternite, ventral view; F, telson, dorsal view; G, left fourth pereopod, dactylus and propodus, lateral view; H, same, mesial view; I, right fourth pereopod, dactylus and propodus, lateral view. Scales bars: 1.0 mm.

FIGURE 22. Pagurixus boninensis (Melin, 1939). Male (SL 2.2 mm) from Chichi­jima Island, Ogasawara Islands (CBM­ZC 8472). A, right second pereopod, lateral view; B, same, dactylus, mesial view; A, left third pereopod, lateral view; B, same, dactylus, mesial view. Scale bars: 1.0 mm.

FIGURE 23. Pagurixus festinus McLaughlin & Haig, 1984. Male (SL 1.6 mm) from Kahe Point, Oahu, Hawaii (P. A. McLaughlin’s reference collection). A, shield and cephalic appendages, dorsal view; B, left antennule, lateral view; C, ultimate segment of left antennular peduncle, ventrolateral view; D, same, ventromesial view; E, dactylus and propodus of left fourth pereopod, lateral view; F, same, mesial view; G, sixth thoracic sternite, ventral view; H, coxae of fifth pereopods and eighth thoracic sternite, ventral view; I, telson, dorsal view. Scale bars: 0.5 mm.

FIGURE 25. Pagurixus festinus McLaughlin & Haig, 1984. A–C, female (SL 1.1 mm) from Kahe Point, Oahu, Hawaii (P. A. McLaughlin’s reference collection); D, F, male (SL 1.6 mm) from same lot; E, G, H, male (SL 1.7 mm) from same lot. A, right cheliped, chela and carpus; B, entire right cheliped, mesial view; C, same, lateral view; D, right second pereopod, lateral view; E, left third pereopod, lateral view; F, right second pereopod, dactylus and distal part of propodus, mesial view; G, left third pereopod, dactylus and distal part of propodus, mesial view; H, dactylus and propodus of right third pereopod, lateral view. Scale bars: 0.5 mm.

FIGURE 28. Pagurixus brachydactylus n. sp. Holotype male (SL 2.4 mm) from Chichi­jima Island, Ogasawara Islands (KMNH­Iv 000,021). A, right second pereopod, lateral view; B, left third pereopod, lateral view; C, right second pereopod, dactylus and distal part of propodus, mesial view; D, left third pereopod, dactylus and distal part of propodus, mesial view. Scale bar: 0.5 mm.

FIGURE 33. Pagurixus paulayi n. sp. Holotype male (SL 2.1 mm) from Guam (UF 7301). A, shield and cephalic appendages, dorsal view; B, left antennule, lateral view; C, ultimate segment of left antennular peduncle, ventral view; D, left fourth pereopod, dactylus and propodus, lateral view; E, same, mesial view; F, sixth thoracic sternite, ventral view (damaged); G, coxae of fifth pereopods and eighth thoracic sternite, ventral view; H, telson, dorsal view. Scale bars: 0.5 mm.

FIGURE 35. Pagurixus paulayi n. sp. Holotype male (SL 2.1 mm) from Guam (UF 7301). A, right second pereopod, lateral view; B, left third pereopod, lateral view; C, right second pereopod, dactylus and distal part of propodus, mesial view; D, left third pereopod, dactylus and distal part of propodus, mesial view. Scale bars: 0.5 mm.

FIGURE 39. Pagurixus pseliophorus n. sp. Holotype male (SL 2.8 mm) from Kume­jima Island (CBM­ZC 7856). A, right second pereopod, lateral view; B, left third pereopod, lateral view; C, right second pereopod, dactylus and distal part of propodus, mesial view; D, left third pereopod, dactylus and distal part of propodus, mesial view. Scale bar: 1 mm for A, B; 0.5 mm for D, E.

FIGURE 40. Pagurixus ruber n. sp. A–C, G–I, holotype male (SL 2.4 mm) from Kume­jima Island (CBM­ZC 7862); D–F, paratype male (SL 2.1 mm) from Guam (UF 7305). A, shield and cephalic appendages, dorsal view; B, left antennule, lateral view; C, ultimate segment of left antennular peduncle, ventral view; D, left fourth pereopod, dactylus and propodus, lateral view; E, same, mesial view; F, right fourth pereopod, dactylus and propodus, lateral view; G, sixth thoracic sternite, ventral view; H, coxae of fifth pereopods and eighth thoracic sternite, ventral view; I, telson, dorsal view. Scale bars: 1 mm for A; 0.5 mm for B–I.

FIGURE 43. Pagurixus ruber n. sp. Holotype male (SL 2.4 mm) from Kume­jima Island (CBM­ ZC 7862). A, left cheliped, chela and carpus, dorsal view; B, entire left cheliped, mesial view; C, same, lateral view; D, right second pereopod, lateral view; E, left third pereopod, lateral view; F, right second pereopod, dactylus and distal part of propodus, mesial view; G, left third pereopod, dactylus and distal part of propodus, mesial view. Scale bars: 1 mm.