Oncopagurus indicus ( Alcock, 1905 )

Lemaitre, Rafael, 2014, A worldwide taxonomic and distributional synthesis of the genus Oncopagurus Lemaitre, 1996 (Crustacea: Decapoda: Anomura: Parapaguridae), with descriptions of nine new species, Raffles Bulletin of Zoology 62, pp. 210-301 : 255-259

Oncopagurus indicus ( Alcock, 1905)

Figs. 26 , 51 , 53A

Sympagurus bicristatus var. indicus Alcock, 1905: 105 , pl.10, fig. 4 (type locality: Andaman Sea); Gordan, 1956: 341.

Parapagurus bicristatus indicus – de Saint Laurent, 1972: 112.

Sympagurus indicus – Lemaitre, 1989: 37; 1994: 412.

Oncopagurus indicus – Lemaitre, 1996: 195 , figs. 17, 18; 1997: 594; Zhadan, 1997: 63 (table); Davie, 2002: 88; Poore, 2004: 282, fig. 81b,c; McLaughlin et al., 2005: 246; McLaughlin et al., 2007: 312, unnumbered figs. p. 312, not unnumbered fig. (DW56) p. 313 [= Oncopagurus monstrosus ( Alcock, 1894) , see Remarks]; 2010: 39; Castro, 2011: 29 .

Oncopagurus mironovi Zhadan, 1997: 59 , figs. 2–5 (type locality: Nazca and Sala-y-Gómez Ridges, R/V Professor Stockman, 18 th cruise, sta 1957, 24°31'5"S, 88°31'6"W); Zhadan, 1999: 735, fig. 1A. (See Remarks).

(For complete synonymy see Lemaitre, 1996)

Type material. Syntypes from Andaman Sea, Indian Ocean, probably in Indian Museum, Calcutta (not examined).

Types of Oncopagurus mironovi Zhadan, 1997 : holotype (not examined), R/V Professor Stockman, 18 th cruise, sta 1957, 24°31'5"S, 88°31'6"W, 570–575 m, 29 April 1987, coll. A. N. Mironov: M 3.8 mm ( ZMUM Ma–4830); paratypes: same sta as holotype, M 3.5 mm, ov F 3.3 mm ( MNHN Pg. 5526); additional paratypes (not examined): see Zhadan (1997).

Additional material. Madagascar, NE Mozambique Channel : BENTHEDI: sta DR 37, 12°53'8S, 45°16'2E, 830– 520 m, 26 March 1977: 1 F 1.9 mm ( MNHN Pg.); sta DR 38, 12°54'8S, 45°15'6E, 200–500 m, 26 March 1977: 2 M 2.0– 2.2 mm ( MNHN Pg.); sta DS 122, 11°32'S, 47°23'2 E, 615–625 m, 12 April 1977: 4 M 1.5–2.8 mm, 4 F 1.5–2.7 mm [dismembered] ( MNHN Pg.) . Taiwan:

TAIWAN 2000: sta CP 56, 24°29,8'N, 122°12,6'E, 438 m, 4 August 2000 (2 lots): 1 F 2.8 mm ( NTOU), 1 M 2.8 mm ( NTOU A00370); sta CP 60, 24°41.2'N, 122°11.8'E, 532 m, 4 August 2000: 1 M 4.4 mm ( NTOU 00287 ) —TAIWAN 2003: sta CP 212, 24°34.60'N, 122°5.84'E, 223–260 m, 26 August 2003 (2 lots): 1 M 4.5 mm ( NTOU), 1 M 3.9 mm ( NTOU A00587 ); sta CP 214, 24°28.59'N, 122 017612.66′E, 490–1027 m, 27 August 2003: 1 M 3.4 mm ( NTOU A00288), 1 F 4.6 mm — TAIWAN 2004: sta CP 264, 24°28.07'N, 121°53.55'E, 330– 297 m, 1 September 2004: 2 M 2.8, 3.1 mm ( NTOU A00572 ) — TAIWAN 2005: sta CP 316, 21°40.349'N, 117°43.274'E, 514 m, 17 August 2005: 1 M 3.9 mm ( NTOU) — TAIWAN 2005 : sta CP 314, 21°40.072'N, 117°43.123'E, 506 m, 17 August 2005: 1 F 3.3 mm ( NTOU) — TAIWAN 2006 : sta CP 371, 24º28.521'N, 122º12.821'E, 582–613 m, 26 August 2006: 1 M 2.9 mm ( NTOU). Solomon Islands: SALOMON 1: sta CP 1783, 8°32.8'S, 160°41.7'E, 399–700 m, 29 September 2000: 1 F 1.9 mm ( MNHN Pg.); sta DW 1830, 10°11.3'S, 161°18.8'E, 500–563 m, 4 October 2000: 1 M 3.2 mm ( MNHN Pg. 7020); sta CP 1837, 10°12.8'S, 161°28.6'E, 381–383 m, 5 October 2000: 5 M 2.0– 4.1 mm, 3 F 1.6–2.4 mm, 1 ov F 2.4 mm ( MNHN Pg.) — SALOMON 2: sta CP 2194, 8°24.05'S, 159°26.27'E, 440–521 m, 24 October 2004: 10 M 2.2–4.0 mm, 1 ov F 2.8 mm ( MNHN Pg.); sta CP 2195, 8°24.57'S, 159°26.06'E, 543–593 m, 24 October 2004: 1 M 2.7 mm ( MNHN Pg.); sta CP 2227, 6°38.27'S, 156°13.52'E, 508–522 m, 24 October 2004: 3 M 2.2–3.5 mm, 1 ov F 2.5 mm ( MNHN Pg.); sta CP 2262, 7°57.5'S, 156°51.346'E, 460–487 m, 11 March 2004: 3 M 1.1–3.5 mm, 3 F 2.7–3.4 mm, 4 ov F 2.4–3.3 mm ( MNHN Pg.); sta CP 2263, 7°56.27'S, 156°50.885'E, 485–520 m, 11 March 2004 (2 lots): 1 M 4.3 mm ( MNHN Pg.), 12 M 2.3–4.4 mm, 4 F 3.1–3.3 mm, 11 ov F 2.8–4.6 mm ( MNHN Pg.); sta CP 2266, 7°52.94'S, 156°52.4'E, 560 m, 11 April 2004: 1 ov F 3.1 mm ( MNHN Pg.); sta CP 2272, 8°32.12'S, 157°44.38'E, 380–537 m, 11 May 2004: 1 M 3.9 mm ( MNHN Pg.); sta CP 2290,: 1 M 2.4 mm ( MNHN Pg.). Wallis and Futuna Islands: MUSORSTOM 7: sta DW 556, 11°48.7'S, 178°18.0'W, 440 m, 19 May 1992: 1 F 2.4 mm (MNHN-IU-2013-5550); sta DW 587, 12°17.5'S, 174°44.8'W, 715–720 m, 23 May 1992: 1 M 3.1 mm, 1 ov F 3.4 mm (MNHN-IU-2013-5512); sta DW 598, 12°30.5'S, 174°18.4'W, 702–708 m, 24 May 1992: 1 M 2.7 mm ( USNM 1211218 ). Fiji: BORDAU 1: sta CP 1460, 18°47.06'S, 178°47.29'W, 750–767 m, 6 March 1999: 1 M 2.6 mm ( MNHN Pg. 6434); sta DW 1479, 20°58.05'S, 178°44.94'W, 450–460 m, 9 March 1999: 2 M 1.6, 2.1 mm ( MNHN Pg. 6489). Vanuatu: VOLSMAR: sta CAS 3, 22°24.00'S, 171°49.30'E, 800 m, 31 May 1989: 2 ov F 2.0, 3.1 mm ( USNM 1211205 ) — MUSORSTOM 8: sta DW 1063, 16°15.67'S, 167°18.25'E, 650–719 m, 2 October 1994: 1 M 2.7 mm (MNHN-IU-2013-5504); sta DW 1064, 16°16.02'S, 167°20.55'E, 459 m, 2 October 1994: 1 ov F 2.3 mm ( MNHN Pg.); sta CP 1136, 15°40.62'S, 167°01.60'E, 398–400 m, 11 October 1994: 1 M 1.5 mm ( MNHN Pg.) — BOA 1: sta CP 2412, 15°42.33'S, 167°03.57'E, 373–800 m, 5 September 2005: 2 M 2.8, 3.1 mm ( MNHN Pg.); sta CP 2457, 16°14.18'S, 167°18.49'E, 630–690 m, 12 September 2005: 8 M 3.4– 3.3 mm ( MNHN Pg.) — BOA 0: CP 2310, 14°46'S, 167°07'E, 864–927 m, 15 November 2004: 5 M 4.6–5.1 mm ( MNHN Pg.). Tonga Islands: BORDAU 2: sta DW 1508, 21°02'S, 175°19'W, 555–581 m, 31 May 2000: 2 ov F 2.2, 2.9 mm ( MNHN Pg.); sta DW 1553, 20°42'S, 174°54'W, 650–676 m, 6 June 2000: 1 M 2.1 mm ( MNHN Pg.); sta CP 1565, 20°58'S, 175°16'W, 869–880 m, 9 June 2000: 3 M 3.6–3.9 mm ( MNHN Pg. 6485); sta DW 1618, 24°13'S, 176°18'W, 627–656 m, 18 June 2000: 1 ov F 2.2 mm ( MNHN Pg.); sta DW 1637, 21°05'S, 175°23'W, 464–507 m, 21 June 2000: 2 M 2.6, 2.7 mm ( MNHN Pg.); sta CP 1638, 21°05'S, 175°23'W, 469–520 m, 21 June 2000: 1 M 2.6 mm ( MNHN Pg. 6481); sta CP 1640, 21°09'S, 175°24'W, 564–569 m, 21 June 2000: 2 M 1.9, 2.0 mm ( MNHN Pg. 6482); sta CP 1642, 21°05'S, 175°23'W, 532 m, 21 June 2000 (3 lots): 4 M 1.8–3.0 mm ( MNHN Pg. 6486), 1 M 2.6 mm ( MNHN Pg. 6484), 2 M 1.9, 2.2 mm, 1 ov F 2.0 mm ( MNHN Pg.); sta CP 1643, 21°05'S, 175°22'W, 487 m, 22 June 2000: 2 M 2.3 mm, 1 ov F 2.3 mm ( MNHN Pg. 6487). New Caledonia: BIOCAL: sta DW 33, 23°09.71'S, 167°10.27'E, 675 m, 29 August 1985 (2 lots): 4 M 1.9–2.6 mm ( USNM 1211206 ), 5 M 2.3–3.2 mm (MNHN- IU-2013-5547); sta DW 36, 23°08.64'S, 167°10.99'E, 650 m, 29 August 1985: 1 ov F 2.0 mm ( USNM 1211207 ); sta DW 46, 22°53.05S, 167°17.08E, 570–610 m, 30 August 1985: 2 M 1.7, 3.0 mm, 1 F 3.0 mm ( USNM 1211208 ); sta DW 51, 23°05.27'S, 167°44.95'E, 680–700 m, 31 August 1985 (3 lots): 1 M 3.7 mm (MNHN-IU-2013-5551), 3 M 1.7–2.2 mm, 2 F 1.7, 2.3 mm ( USNM 1211210 ), 11 M 1.4–3.7 mm, 3 F 1.9–3.0 mm (MNHN- IU-2013-5553); sta CP 61, 24°11.70'S, 167°31.80'E, 1070 m, 2 September 1985: 1 M 3.3 mm, 1 ov F 2.3 mm ( USNM 1211211 ); sta DW 66, 24°55.43'S, 168°21.67'E, 505–515 m, 3 September 1985 (2 lots): 1 M 3.1 mm, 1 F 2.7 mm (MNHN-IU-2013-5545 Pg.), 5 M 1.3–1.4 mm, 2 F 1.2, 1.4 mm, 5 imm 1.1–1.2 mm (MNHN-IU-2013-5546) — CHALCAL 2: sta DW 72, 24°54.50'S, 168°22.30'E, 527 m, 28 October 1986 (2 lots): 3 M 1.9–3.1 mm, 1 F 2.6 mm (MNHN-IU-2013-5548), 1 M 2.1 mm, 1 F 2.5 mm ( USNM 1211212 ); sta DW 74, 24°40.36'S, 168°38.38'E, 650 m, 29 October 1986: 10 M 2.0– 3.7 mm, 2 F 2.2, 2.6 mm, 1 ov F 2.4 mm (MNHN-IU-2013-5552); sta DW 75, 24°39.31'S, 168°39.67'E, 600 m, 29 October 1986: 14 M 2.2–3.6 mm, 8 F 2.1–4.0 mm, 3 ov F 2.5–3.6 mm ( USNM 1211213 ) — SMIB 3: sta DW 2, 24°53.40'S, 168°21.70'E, 530 m, 20. 5.1987: 2 M 2.2, 3.0 mm (MNHN-IU-2013-5549); sta DW 3, 24°55.00'S, 168°21.70'E, 513 m, 20 May 1987 (2 lots): 1 F 2.2 mm, 1 ov F 2.6 mm (MNHN- IU-2013-5555),1 M 3.1 mm ( USNM 1211204 ) — MUSORSTOM 5: sta DW 301, 22°06.90'S, 159°24.60'E, 487–610 m, 12 October 1986: 1 M 1.5 mm ( USNM 1211215 ) — MUSORSTOM 6: sta DW 453, 21°00.50'S, 167°26.90'E, 250 m, 20 February 1989: 2 M 1.6, 1.8 mm ( USNM 1211216 ); sta DW 457, 21°00.42′S, 167°28.71'E, 353 m, 20 February 1989: 1 F 1.6 mm (MNHN- IU-2013-5554); sta DW 480, 21°08.50'S, 167°55.98'E, 380 m, 22 February 1989: 1 F 1.7 mm ( USNM 1211217 ); sta DW 488, 20°49.20'S, 167°06.44'E, 800 m, 24 February 1989: 1 M 2.4 mm ( USNM 1211214 ) — BERYX 11: sta DW 10, 24°44.75'S, 168°09.90'E, 560–600 m, 15 October 1992: 1 F 2.4 mm ( MNHN Pg.); sta C 28, 23°38.80'S, 167°43.00'E, 430–490 m, 18 October 1992: 1 M 2.5 mm ( MNHN Pg.) — SMIB 8: sta DW 152, 24°54.35'S, 168°22.23'E, 514–530 m, 27 January 1993: 1 M 3.1 mm ( MNHN Pg.); sta DW 153, 24°53.55'S, 168°21.33'E, 547–560 m, 27 January 1993: 2 M 3.1, 3.2 mm, 1 ov F 3.2 mm ( ZMMU); sta DW 177, 23°39.06'S, 168°00.05'E, 320–370 m, 29 January 1993: 1 M 2.2 mm ( MNHN Pg.) — BATHUS 1, 20°57.28'S, 165°35.30'E, 255–280 m, 14 March 1993: 2 M 1.9, 2.0 mm ( MNHN Pg.) — BATHUS 2: sta CP 738, 23°02.09'S, 166°56.61'E, 358–647 m, 13 May 1993: 1 M 2.4 mm ( MNHN Pg.) — BATHUS 3: DW 776, 24°44.24'S, 170°08.0'E, 770–830 m, 24 November 1993 (2 lots): 1 M 3.1 mm (MNHN-IU-2013-5506), 4 M 2.2–3.3 mm, 4 F 2.2–2.7 mm, 1 ov F 2.4 mm (MNHN-IU-2013-5501); sta DW 778, 24°43.49'S, 170°07.07'E, 750–760 m, 24 November 1993 (2 lots): 1 ov F 2.1 ( MNHN Pg. 6505), 1 ov F 1.8 mm (MNHN- IU-2013-5505); sta DW 785, 23°56.10'S, 169°45.70'E, 607–608 m, 25 November 1993: 2 M 3.4, 4.0 mm ( MNHN Pg. 7014); sta DW 794, 23°48.35'S, 169°49.10'E, 751–755 m, 26 November 1993: 1 M 3.2 mm (MNHN-IU-2013-5503); sta DW 800, 23°35.12'S, 169°36.73'E, 655 m, 26 November 1993: 2 M 2.5, 2.9 mm ( MNHN Pg.); sta CP 822, 23°19.92'S, 167°57.45'E, 950–980 m, 29 November 1993: 1 F 3.5 mm ( MNHN Pg.) — HALIPRO 1: sta CP 858, 21°42.81'S, 166°41.95'E, 1000–1120 m, 20 March 1994: 1 M 2.8 mm, 2 F 1.7, 1.9 mm (MNHN-IU-2013-5502); sta CP 869, 21°14.84'S, 165°55.49'E, 450–490 m, 23 March 1994: 1 juv sex indet. 1.5 mm ( MNHN Pg.) — BATHUS 4: sta DW 890, 21°01.20'S, 164°27.34'E, 500–520 m, 2 August 1994: 1 M 2.0 mm ( MNHN Pg.); sta CP 913, 18°56.23'S, 163°04.86′E, 777–820 m, 5 August 1994: 1 M 2.1 mm, 1 F 2.4 mm (MNH-IU-2013-5507); sta CP 946, 20°33.81'S, 164°58.35'E, 386–430 m, 10 August 1994: 1 F 1.5 mm (MNHN-IU-2013-5500) — SMIB 10: sta DW 204, 24°57'S, 168°21'E, 513–553 m, 10 January 1995: 1 M 2.6mm ( MNHN Pg.) — LITHIST: sta CP 8, 24°54.24'S, 168°21.35'W, 540 m, 11 August 1999: 1 M 1.9 mm ( MNHN Pg. 6875) — NORFOLK 1: sta DW 1698, 24°40'186S, 168°39'545E, 562–576 m, 24 June 2001: 2 M 2.8, 3.5 mm, 1 ov F 2.4 mm ( MNHN Pg. 6501); sta CP 1716, 23°21'525S, 168°02'598 E, 276– 266 m, 26 June 2001: 1 ov F 1.7 mm ( MNHN Pg. 6506) — NORFOLK 2: sta DW 2060, 24°39.84 S, 168°38.50 E, 582–600 m, 25 October 2003: 1 F 1.8 mm ( MNHN Pg.); sta DW 2064, 25°16.59'S, 168°55.64'E, 609–691 m, 26 October 2003: 1 M 2.5 mm ( MNHN Pg.); sta DW 2070, 25°22.97'S, 168°57.12'E, 630–1150 m, 26 October 2003: 1 M 2.1 mm ( MNHN Pg.); sta DW 2073, 25°24.21'S, 168°19.46'E, 609 m, 27 October 2003: 1 M 2.5 mm ( MNHN Pg.); sta DW 2077, 25°20.63'S, 168°18.53'E, 666–1000 m, 27 October 2003: 1 M 3.4 mm ( MNHN Pg.); sta DW 2084, 24°52.00'S, 168°22'00E, 586–730 m, 27 October 2003: 1 M 3.5 mm, 2 F 2.8, 3.4 mm ( MNHN Pg.) — EBISCO: sta DW 2536, 22°18.051'S, 159°28.661'E, 650–713 m, 10 October 2005: 1 M 2.8 mm ( MNHN Pg.); sta DW 2574, 20°20.964'S, 158°45.149'E, 358–374 m, 14 October 2005: 1 M 2.0 mm ( MNHN Pg.); sta DW 2603, 19°37.761'S, 158°43.898'E, 570– 568 m, 18 October 2005: 2 M 1.9, 2.0 mm ( MNHN Pg.); sta DW 2625, 20°04.872'S, 160°20.039'E, 627–741 m, 20 October 2005: 1 M 2.5 mm ( MNHN Pg.). Hawaiian Islands: USFCS Albatross: sta 3919, Oahu, SW Diamond Head light, 21°15'00"N, 157°48'00"W, 402–470 m, 6 May 1902: 1 F 2.7 mm ( USNM 1154274 ); R/ V Townsend Cromwell, sta TC 40–76, 21°06.8'N, 156°31.9'W, 438.9 m, 22 November 1968:1 M 2.8 mm, 1 ov F 3.3 mm ( BPBM). Marquesas Islands: MUSORSTOM 9: sta CP 1169, 8°58,6'S, 140°04,6'W, 391–408 m, 24 August 1997: 1 M 3.4 mm ( MNHN Pg. 6502); sta DW 1206, 9°51.4'S, 139°09.1'W, 352–358 m, 28 August 1997: 1 M 2.6 mm ( MNHN Pg. 6498); sta DW 1207, 9°50.8'S, 139°09.8'W, 500–525 m, 28 August 1997: 1 M 2.7 mm, 1 F 2.0 mm ( MNHN Pg.); sta DR 1255, 9°38,5'S, 139°48,4'W, 416–440 m, 2 September 1997: 1 M 2.2 mm ( MNHN Pg. 6500); sta CP 1269, 7°56.3'S, 140°43.3'W, 420–430 m, 4 September 1997: 1 ov F 3.0 mm ( MNHN Pg. 6503); sta CP 1270, 7°56.0'S, 140°43.2'W, 497–508 m, 4 September 1997: 4 M 2.6–3.1 mm ( MNHN Pg. 6492); sta CP 1272, 7°55.5'S, 140°43.6'W, 660–680 m, 4 September 1997 (2 lots): 2 M 3.0, 3.6 mm ( MNHN Pg. 6497), 1 M 3.5 mm ( MNHN Pg.); sta CP 1276, 7°51.9′S, 140°37.3'W, 800–805 m, 5 September 1997 (2 lots): 7 M 3.7–4.5 mm, 1 F 3.4 mm ( MNHN Pg. 6490), 1 M 3.6 mm ( MNHN Pg.); sta CP1278, 7°58.9'S, 140°43.3'W, 87–98 m, 6 September 1997: 1 M 3.3 mm ( MNHN Pg. 6499); sta DW 1281, 7°47.8'S, 140°20.8'W, 450–455 m, 7 September 1997: 5 M 1.9–3.7 mm, 2 F 2.3, 3.4 mm, 4 ov F 2.7–2.8 mm ( MNHN Pg. 6493); sta DW 1286, 7°53.1'S, 140°39.2'W, 760 m, 7 September 1997: 1 M 4.8 mm ( MNHN Pg. 6495); sta CP 1307, 8°57.9'S, 140°15.8'W, 708–738 m, 10 September 1997: 2 M 2.8, 4.3 mm, 3 F 2.5–3.3 mm ( MNHN Pg. 6496). French Polynesia: Society Islands, Moorea Island , DW 3463, 17.5667°N, 149.9°S, 460–505 m, 20 October 2009: 1 M 1.5 mm ( UF23838 ). — Austral Islands: BENTHAUS: sta DW 1884, 27°53.75'S, 143°32.9'W, 570–620 m, 6 November 2002: 8 M 2.3–3.6 mm ( MNHN Pg.); sta DW 1887, 27°51.59'S, 143°32.68'W, 750–1000 m, 6 November 2002: 1 M 3.6 mm ( MNHN Pg.); sta DW 1898, 27°34.29'S, 144°26.65'W, 580–820 m, 8 November 2002: 2 M 2.6, 2.7 mm ( MNHN Pg.); sta DW 1955, 23°18.52'S, 149°25.71'W, 750–850 m, 18 November 2002: 2 M 3.0, 4.1 mm ( MNHN Pg. 7015); sta DW 1957, 23°18.8'S, 149°29.34'W, 558–1000 m, 18 November 2002: 2 M 3.2, 3.6 mm, 6 F 1.9–2.8 mm ( MNHN Pg. 7016); sta DW 1961, 23°20.89'S, 149°33.51'W, 470–800 m, 19 November 2002: 1 M 2.8 mm ( MNHN Pg. 7017); sta CP 1965, 23°21.35'S, 149°33.92'W, 500–1200 m, 19 November 2002: 4 M 2.6–4.3 mm, 1 F 3.1 mm ( MNHN Pg.); sta CP 1967, 23°21.44'S, 149°34.25'W, 600–1200 m, 19 November 2002: 4 m 3.5–4.3 ( MNHN Pg.); sta DW 1975, 23°24.09'W, 150°44.35'S, 600–691 m, 20 November 2002: 1 ov F 2.6 mm ( MNHN Pg. 7018); sta DW 2005, 22°28.09'W, 151°18.30'W, 680–1800 m, 24 November 2002: 1 F 2.6 mm ( MNHN Pg. 7019); sta DW 2018, 22°37.15'S, 152°49.06'W, 770–771 m, 25 November 2002: 3 M 2.2–3.5 mm ( MNHN Pg.) .

For additional material examined see Lemaitre (1996).

Diagnosis. Shield ( Fig. 26A ) as long as broad, rostrum broadly rounded, with low mid–dorsal ridge; lateral projections subtriangular, usually terminating in small spine. Ocular peduncles more than half length of shield; ocular acicles subtriangular, terminating in strong spine; corneas slightly dilated. Antennular peduncle ( Fig. 26A ) exceeding distal margin of cornea by full length of ultimate segment. Antennal peduncle ( Fig. 26A ) at most reaching distal margin of cornea; fourth segment with small spine on dorsolateral distal angle; second segment with dorsolateral distal angle terminating in strong simple or multifid spine; acicle reaching distal margin of cornea, mesial margin with 8–11 spines; flagellum with few setae about 1 flagellar article in length. Third maxilliped with crista dentata of about 10 teeth, proximal teeth slightly larger than distal. Right cheliped ( Fig. 26B–G ) with moderately dense setae, chela operculate, proportions and armature exhibiting sexual dimorphism; males with palm varying from as long as broad to slightly longer than broad, dorsomesial margin always well delimited by row of spines, ventromesial margin varying from weakly to well delimited by row of tubercles or spines, mesial face occasionally weakly expanded distomesially; females with palm broader than long, mesial face concave and expanded distomesially (more so in large females sl> 3.0 mm); in both sexes, dorsal face of palm with scattered small spines or tubercles often arranged in irregular rows medially, ventral face of palm mostly smooth; carpus with numerous small tubercles or spines mostly on dorsal and dorsolateral surfaces. Left cheliped usually weakly calcified on lateral face of carpus; palm unarmed or with dorsomesial row of few small spines; dorsal margin of carpus with irregular row of small spines, or few small tubercles, or unarmed except for dorsodistal spine. Ambulatory legs with dactyls ( Fig. 26H ) each having row of about 4–8 small corneous spinules on ventromesial margin; carpus with small dorsodistal spine; merus of third pereopods unarmed dorsally except for setae, or with row of 2–8 small spines (occasionally with 1 spine; Fig. 26I ). Anterior lobe of sternite XII (between second ambulatory legs) rounded, setose, with or without subterminal spine. Fourth pereopod propodal rasp ( Fig. 26J ) with 1 row of ovate scales at least distally. Uropods and telson markedly asymmetrical; telson ( Fig. 26K ) lacking or with obsolete transverse suture, posterior lobes separated by shallow U-shaped median cleft, terminal margins armed with often strongly curved corneous spines. Male with paired first and second gonopods ( Fig. 26L, M ); first gonopod with weakly concave distal lobe; second gonopod with distal segment nearly flat, setose distally. Females with vestigial right second pleopod.

Variations. See Lemaitre (1996).

Colouration ( Fig. 53A ). Shield generally whitish or cream coloured, with faint undefined orange areas on anteromedian and lateral surfaces. Ocular peduncles with dorsolateral faces faint orange. Antennular peduncles with segments light orange. Antennal peduncles mostly whitish except for faint orange areas dorsolaterally, and light to transparent orange flagella. Chelipeds with proximal two-thirds of dorsal faces of meri and carpi orange and white distally; dorsal surface of chelae light orange proximally, otherwise white. Ambulatory legs generally whitish; dactyls entirely white; carpi and propodi orange on half to proximal two-thirds; meri white, with orange proximally and on dorsal margin; ischia light orange. Fourth and fifth pereopods mostly whitish, with at most small, faint orange area on lateral faces of propodi. Uropods and telson white or cream.

Habitat. Gastropod shells occasionally with one or more anthozoan polyps attached to the shell.

Distribution. Indian Ocean: Zanzibar; Mozambique Channel, Madagascar; Maldives. Western Pacific: Indonesia; Taiwan; Solomon Islands; Wallis and Futuna; Fiji; Vanuatu, Tonga Islands; New Caledonia; Australia; Philippines. Central and South Pacific: Hawaiian Islands; Marquesas Islands; French Polynesia; Nazca and Sala-y-Gómez Ridge. Depth: 87–1800 m.

Remarks. Oncopagurus indicus is widely distributed and often found abundantly, from the western Indian Ocean, and across the western and central Pacific, to the Nazca and Sala-y-Gómez Ridges in the south Pacific. Previous to this study, O. indicus had been reported westward in the Indo-Pacific only from the Philippines and Hawaiian Islands ( Lemaitre, 1996). It’s presence herein documented from French Polynesia and the Nazca and Sala-y-Gómez Ridges, considerably expands the distribution of this species.

A detailed evaluation of the morphological variations and its effect on the taxonomy of this species, and its close affinities and differences with Oncopagurus monstrosus , was discussed by Lemaitre (1996). Since then, the study of considerable additional material of O. indicus obtained during French campaigns and reported herein, has amplified even more its known distribution, and reinforced the concept of O. indicus as a morphologically variable and sexually dimorphic species. As discussed by Lemaitre (1996) and illustrated herein, that dimorphism is more strongly manifested in the shape and armature of the right chela.

Males of Oncopagurus indicus can often be difficult to separate from males of O. monstrosus , although there are some clear distinctions. In males of O. indicus , the mesial face of the right palm is at most weakly expanded distomesially, and the palm has a distinct, spinose ventromesial margin ( Fig. 26B, C ); in males of O. monstrosus the mesial face is similar to that of females ( Fig. 28B, D–G ). Females of these two species can be separated by the shape and armature of the mesial face of the palm of the right cheliped, which in O. indicus is expanded distomesially, and the palm has a well delimited ventromesial, spinose margin ( Fig. 26D–F ); in O. monstrosus the mesial face of the palm is not expanded distally, and the ventromesial face is rounded, without any distinct ventromesial margin ( Fig. 28E, F ). In both sexes of O. indicus the ocular peduncles are nearly subequal in width throughout the peduncle, and the width of the corneas is subequal to the distal width of the peduncles ( Fig. 26A ); in both sexes of O. monstrosus the peduncles increase in width distally, are slightly constricted medially, and the width of the corneas is distinctly greater than that of the peduncles ( Fig. 28A ).

Observations and photographs of fresh specimens obtained during this study have also revealed subtle but distinct colouration differences between Oncopagurus indicus and O. monstrosus . The orange colouration is overall stronger in O. indicus than in O. monstrosus . The most visible difference in colouration is on the orange pattern of carpi and propodi of the ambulatory legs. In O. indicus the meri, carpi and propodi have uninterrupted orange bands ( Fig. 53A ), whereas in O. monstrosus the meri, carpi and propodi are orange interrupted medially by a white area ( Figs. 53B, C ).

In their catalogue of hermit crabs from Taiwan, McLaughlin et al. [2007: 313, unnumbered fig. (DW56)] included under Oncopagurus indicus a colour photograph of a female specimen from station DW 56 (shield length 2.8 mm). The specimen used for that photograph has not been found, but it is clear that based on differences in colour pattern alone with the other photographs published therein (p. 312) for O. indicus and comparisons with confirmed specimens of O. monstrosus photographed alive (see Fig. 53B, C ), that it is not O. indicus , and instead represents O. monstrosus .

A sexual dimorphism of the right palm similar to that of Oncopagurus indicus has been documented in the Atlantic congener, O. bicristatus (A. Milne-Edwards, 1880) . However, in O. bicristatus , the dimorphic features are reversed, with the distal expansion of the mesial face of the palm distinctly developed in males instead of females (see Lemaitre, 1989 as Sympagurus bicristatus ).

The morphology of the right cheliped and colour pattern of Oncopagurus indicus is also similar to that of O. tuamotu (see Remarks under O. tuamotu ).

Figures

Fig. 26. Oncopagurus indicus (Alcock, 1905): A–C, H–M, male 4.0 mm, Queensland, Australia (QM W16600); D–G, female 3.3 mm Queensland (QM W16599). A, shield and cephalic appendages, dorsal; B, carpus and chela of male right cheliped, dorsal; C, chela of same, mesial; D, carpus and chela of female right cheliped, dorsal; E, F, G, chela of same, ventral (E), mesial (F), lateral (G); H, dactyl of right first ambulatory leg, mesial; I, merus of right second ambulatory leg, lateral; L, left first gonopod, mesial; M, left second gonopod, anterior. Scale bars = 1 mm (A, C–H, L, M); 0.5 mm (I–K). [Adapted from Lemaitre (1996)].

Fig. 51. Bathymetric distribution of Oncopagurus species from the world, with maximum and minimum depths (meters) indicated for each.

Fig. 53. Colouration in species of Oncopagurus (in life or fresh, except where noted). A, O. indicus (Alcock, 1905): Taiwan, TAIWAN 2003, sta CP 214: female 4.6 mm (NTOU). B, C, O. monstrosus (Alcock, 1894): B, [not sexed or measured], Taiwan (NTOU); C, male 3.6 mm, TAIWAN 2004, sta CP 269 (NTOU). D, O. orientalis (de Saint Laurent, 1972): male 3.6 mm, Taiwan, TAIWAN 2004 (MNHN Pg). E, F, O. rossanae, new species, French Polynesia, BENTHAUS: E, paratype male 2.5 mm, sta DW 1905 (MNHN Pg 6692); F, holotype M 2.9 mm, sta DW 1973 (MNHN-IU-2013-6869). G, O. tuamotu (Lemaitre, 1994): [not sexed or measured], French Polynesia, Moorea (UF). (Photographs by: Tin-Y. Chan [A–D]; Joseph Poupin [E, F]; Gustav Paulay [G]).

Fig. 28. Oncopagurus monstrosus (Alcock, 1894): A–D, H–L, lectotype, male 4.2 mm, Bay of Bengal (USNM 156566); E, female 3.4 mm, Indonesia (USNM 168939); F, male 4.2 mm, Indonesia (USNM 168940); G, male 5.1 mm, Philippines (USNM 168931). A, shield and cephalic appendages, dorsal; B, carpus and chela of right cheliped, dorsal; C, D, chela of same, lateral (C), mesial (D); E, right cheliped of female, dorsal; F, G, chela of male, ventral; H, dactyl of right first ambulatory leg, mesial; I, propodus and dactyl of left fourth pereopod, lateral; J, telson, dorsal; K, left first gonopod, mesial; L, left second gonopod, anterior. Scale bars = 1 mm (A, H); 2 mm (B–G); 0.5 mm (I–L). [Adapted from Lemaitre (1996)].