Leucosiid crabs from Papua New Guinea, with descriptions of eight new species (Crustacea: Decapoda: Brachyura) Author Galil, Bella S. Author Ng, Peter K. L. text Zootaxa 2015 4027 4 451 486 journal article 10.11646/zootaxa.4027.4.1 7e77f875-e8de-478e-a96b-19d376e00e3a 1175-5326 234517 3B32D183-45BA-41F9-82A9-C9C108D53899 Tanaoa retpela sp. nov. ( Figs. 5 A, 14, 15F–K) Material examined . Holotype : male ( 36.5 mm ) (MNHN-IU-2013-7961), stn CP3984, Bismarck Sea, northwest Long I., 05°12'S 146°59'E , 500 m , 6.12.2012 . Paratypes : 1 male (39.0 mm) ( ZRC 2015.272), stn CP3978, Bismarck Sea, north Bagabag Is., 04°45'S 146°12'E , 456–582m , 5.12.2012 . Additional material: BIOPAPUA – 1 female ( 29.5 mm ) (MNHN-IU-2011-3835), stn CP3653, west of New Hanover, 02°13’S 150°23’E , 680–700 m , 28.08.2010 ; 2 males ( 38.4 mm , 29.8 mm ) (MNHN-IU-2011-914), stn CP3655, west of New Hanover, 02°15’S 150°16’E , 402–440 m , 28.08.2010 ; 1 male ( 39.1 mm ) (MNHN-IU- 2011-2098 ), stn CP3669, north of Rabaul, 04°08’S 151°56’E , 382–389 m , 24.09.2010 ; 1 female ( 28.7 mm ) (MNHN-IU- 2011-2481 ), stn CP3681, Vitu I., 04°38’S 149°27’E , 564–712 m , 27.09.2010 ; 1 male ( 28.6 mm ) (MNHN-IU- 2011-2478 ), stn CP3682, Vitu I., 04°38’S 149°28’E , 515–812 m , 27.09.2010 ; 3 juveniles ( 11.7–12.5 mm ) (MNHN-IU- 2011-2563 ), stn DW3748, seamounts near Bougainville, 05°37’S 154°01’W , 398–399 m , 12.10.2010 ; 1 male ( 21.4 mm ) (MNHN-IU- 2011- 2710 ), stn CP3695, Feni Is., 02°10’S 147°15’W , 198 m , 14.10.2010 ; 3 females (19.5–21.0 mm) (MNHN-IU- 2011- 2299 ), stn CP3760, Is., 03°58’S 153°43’W , 613–660 m , 14.10.2010 . FIGURE 5 . Colours in life. A, Tanaoa retpela sp. nov. , paratype female (29.5 mm) (MNHN-IU-2011-3835), stn CP 3653; B, Toru pilus , male (11.5 mm) (MNHN-IU-2013-1556), stn CP4055; C, Urashima pustuloides , broken juvenile (MNHN-IU-2013- 1494), stn CP4035; D, Urnalana chevreti , male (10.6 mm) (MNHN-IU-2013-615), stn PD22; E, Leucosia rubripalma , male (20.8 mm) (MNHN-IU-2013-1199), stn PR176; F, Urnalana flammea sp. nov. , holotype male (9.3 mm) (MNHN-IU-2013- 1341), stn PR227. FIGURE 6 . A–E, Alox naispela sp. nov. , holotype ovigerous female (8.3 mm) (MNHN-IU-2013.1352), stn PD31; F–J, Alox liklik sp. nov. , holotype female (8.3 mm) (MNHN-IU-2013.8855), stn PR152. A, F, overall habitus; C, H, frontal view of cephalothorax; D, I, right lateral view of cephalothorax; E, J, outer view of right chela; F, G, ventral surfaces, thoracic sternum and abdomen. FIGURE 7 . A, C, E, F, Alox rugosum , male (7.3 mm) (MNHN-IU-2013.8854a), stn PR69; B, D, G, Alox rugosum , female (8.0 mm) (MNHN-IU-2013.17888), stn PR69; H, Oreotlos etor Tan & Richer de Forges, 1993, male (4.3 mm) (MNHN-IU-2013- 17889. A, B, overall habitus; C, frontal view of cephalothorax; D, right lateral view of cephalothorax; E, outer view of right chela; F, G, ventral surfaces, thoracic sternum and abdomen. FIGURE 8 . A, Alox naispela sp. nov. , paratype female (6.6 mm) (ZRC 2015.269), stn PD73; B, D, E–H, Alox rugosum , male (5.8 mm) (ZRC 2015.267), stn PB12; C, Alox liklik sp. nov. , holotype ovigerous female (8.3 mm) (MNHN-IU-2013-8855), stn PR152; I, J, K, Alox rugosum , male (7.3 mm) (MNHN-IU-2013-8854), stn PR69. A–C, left third maxilliped; D, right last ambulatory leg; E, male abdomen; F, G, I, J, left G1; H, K, right G2. Scales: A–E = 1.0 mm; F–K = 0.5 mm. FIGURE 9 . Ryphila bertrandi sp. nov. A, C–F, holotype female (11.5 mm) (MNHN-IU-2013-12749), stn PD72; B, paratype ovigerous female (9.6 mm) (ZRC 2015.270), stn PD72. A, B, overall habitus; C, frontal margin and orbits; D, frontal view of cephalothorax and chelipeds; E, left lateral view of cephalothorax; F, third maxillipeds. Description. Carapace rounded, slightly wider than long, globose; gastric, cardiac, intestinal regions laterally demarcated by deep grooves ( Fig. 14 A). Dorsal surface covered densely by rounded, pearliform granules of various sizes; 4 pairs of pits along branchiocardiac line, additional pair on mesogastric region ( Fig. 14 A). Intestinal region swollen, anteriorly with rounded median carina, posteriorly with granular tubercle ( Fig. 14 A). Front narrow, slightly produced, upturned, closely set with granules, divided into 2 rounded lobes ( Fig. 14 A–C). Eyes small, retractable within orbit, minutely granulose eyestalk exposed ( Fig. 14 B). Outer orbital margin with 3 sutures. Vshaped gap proximally on ventral margin. Antennular fossae below frontal lobes oblique, antennules obliquely folded, basal antennular operculiform, sealing lower half of antennular aperture when retracted. Antennae small, slender, basal antennal article inserted in orbital hiatus. Postorbital region concave. Anterior margin of efferent branchial channel convex, produced, bilobed, separated by narrow groove from lower orbital margin ( Fig. 14 B, C). Outer surface of third maxillipeds granular, granules more prominent anteriorly, forming granular ridge mesially on endopod ( Fig. 14 C). Hepatic margin medially with granular tubercle ( Fig. 14 B, C). Subhepatic region produced, inflated, with horizontal line medially free of granules ( Fig. 14 B, C). Epibranchial margin with 3 equidistant granular tubercles ( Fig. 13 A). Posterolateral margins rounded. Posterior margin of carapace narrow, laterally with 2 prominently granular tubercles ( Fig. 14 A). FIGURE 10 . Ryphila bertrandi sp. nov. , holotype female (11.5 mm) (MNHN-IU-2013-12749), stn PD72. A, inner view of right chela; B, dorsal view of right cheliped merus; C, anterior view of left cheliped merus; D, thoracic sternum and vulvae; E, ventral surfaces, thoracic sternum and abdomen. FIGURE 11 . Tanaoa distinctus (Rathbun, 1906) , male (37.5 mm), stn 34, Hawaiian Islands. A, overall habitus; B, frontal view of cephalothorax; C, third maxillipeds; D, thoracic sternum and abdomen; E, telson; F, outer view of left chela; G, right last ambulatory leg.

FIGURE 12 . Tanaoa serenei (Richer de	Forges,	1983), male	(33.2 mm)	(ZRC 2000.565), Tumon	Bay, Guam. A, overall
habitus; B, frontal view of cephalothorax;	C, third	maxillipeds;	D, thoracic	sternum and abdomen; E,	telson; F, outer view of
left chela; G, left last ambulatory leg.

FIGURE 13 . Tanaoa kuka sp. nov. , holotype male (33.8 mm) (MNHN-IU-2013.7963), stn CP3984. A, overall habitus; B, frontal view of cephalothorax; C, third maxillipeds; D, thoracic sternum and abdomen; E, telson; F, outer view of left chela; G, left last ambulatory leg. FIGURE 14 . Tanaoa retpela sp. nov. , holotype male (36.5 mm) (MNHN-IU-2013-7961), stn CP3984. A, overall habitus; B, frontal view of cephalothorax; C, third maxillipeds; D, thoracic sternum and abdomen; E, telson; F, outer view of left chela; G, left last ambulatory leg. Chelipeds slender, subequal, covered with small granules on all articles, including fingers ( Fig. 14 A, F). Cheliped merus, subcylindrical, not nearly as long as carapace; palm subcylindrical, 0.6 as long as merus; fingers longer than dorsal margin of palm, granules arraigned in longitudinal lines, cutting edges denticulate ( Fig. 14 A, F). Ambulatory legs slender; decreasing in size posteriorly; merus, carpus, propodus granular, granules more prominent dorsally; dorsal surface of dactylus setose, dactylar tips corneous ( Fig. 14 A, G). FIGURE 15 . A–E, Tanaoa kuka sp. nov. , holotype male (33.8 mm) (MNHN-IU-2013.7963), stn CP3984; F–K, Tanaoa retpela sp. nov. , holotype male (36.5 mm) (MNHN-IU-2013-7961), stn CP3984. A, F, left G1 (ventral view); B, G, left G1 (dorsal view); C, D, H, J, distal part of left G1 (ventral view); I, distal part of left G1 (dorsal view); E, K, left G2. Scales: A–C, E–I, K = 1.0 mm; D, J = 0.5 mm. Thoracic sternites set with granules of various sizes; sternite 4 anteriorly inflated ( Fig. 14 D). Male abdominal cavity deep, nearly reaching buccal cavity, anterior margin of cavity ogive, slightly raised ( Fig. 14 D). Male abdomen triangular, elongated; abdominal somites 1, 2 transversely narrow; somite 1 yoke-like, somite 2 medially convex as it fits into cavity of somite 1; somites 3–6 fused, proximo-lateral regions greatly inflated, granular; subterminally with horizontal ridge, anterior margin with quadrate denticle; telson slender, 1/3 as long as fused somites, not reaching tip of abdominal cavity ( Fig. 14 D, E). G1 elongated, slightly sinuous, attenuate, with preapical digitate process perpendicular to tip, opening facing dorsally ( Fig. 15 F–J); G2 short, distally scoop-like ( Fig. 15 K). Colour in life . Carapace bright orange-red mottled bone-white. Cheliped merus pale orange, distal part bright orange; palm, fingers mottled pale orange. Ambulatory legs pale ( Fig. 5 A). Etymology . From retpela for “red” or “orange” in Tok Pisin, the Pidgin language spoken in Papua New Guinea . The name is used as a noun in apposition. Remarks . Tanaoa distincta , T. serenei , T. kuka sp. nov. and T. retepela sp. nov. are all superficially similar in external appearance. Adults, however, are easy to separate using several reliable characters. Ng & Richer de Forges (2007) appraised the taxonomy of T. distincta and T. serenei , noting that the granulation degree and pattern on the carapace was reliable as a character, and their G1 differ. Among the four species, the granules on the carapace are finest in T. kuka sp. nov. ( Fig. 13 A, B), T. distincta slightly coarser ( Fig. 11 A, B). In T. serenei , the granules are large and densely packed (Fig. 12A, B), while in T. retepela sp. nov. the granules are spaced further apart ( Fig. 14 A, B). Tanaoa kuka sp. nov. is distinguished from the named species by its proportionately elongated chela and palm ( Figs. 13 A, F, 11A, F, 12A, F, 14A, F). With regards to the ambulatory legs, the meri of T. serenei and T. kuka sp. nov. are proportionately the most slender and longest; but whereas in T. serenei , the meri bear sharp granules (Fig. 12A, G) in T. kuka sp. nov. the meri are smoother ( Fig. 13 A, G). The ambulatory meri of T. distincta and T. retepela sp. nov. are proportionately shorter ( Figs. 11 A, G, 14A, G). The G1 of T. distincta is distinct in that the distal part has broad folds or is only subtruncate, lacking subdistal processes (Ng & Richer de Forges 2007 : fig. 4A–D). The G1 of T. kuka sp. nov. bears a subdistal bifurcate process ( Fig. 15C, D ). The G1 of T. serenei and T. retepela sp. nov. are superficially similar ( Fig. 15 F–J; Ng & Richer de Forges 2007 : fig. 4E, F) in that there is a long subdistal process which tapers to a sharp tip. The overall gonopod structure of T. retepela sp. nov. is nevertheless relatively stouter and the subdistal process relatively shorter ( Fig. 15 F–J) compared to the more slender one of T. serenei which has a relatively longer subdistal process (Ng & Richer de Forges 2007 : fig. 4E, F). Geographical Distribution . This species is known only from the type locality, Papua New Guinea .