Danarma leptomerus (Davie & Ng, 2013)

Chiromantes obtusifrons – Lin et al., 2011: 45 (with colour photographs).

Chiromantes leptomerus Davie & Ng, 2013: 19, figs. 3D–F, 4C, 5D, 6D, 7D, 8C, 9D, 13F–J; Li & Chiu, 2013: 41; Ng et al., 2017b: 103.

Material examined. Holotype male (16.8 × 12.7 mm) (NMNS 7028-001 part of ex ZRC 2000.1823), Pingtung County, Hsiang Chiaowan, Taiwan, coll. H.-C. Liu, 25 August 1999.

Paratypes – 2 males (13.4 × 10.3 mm, 16.4 × 12.7 mm) (ZRC 2000.1860), 1 male (16.2 × 12.4 mm), 1 female (18.1 × 13.4 mm) (QM-W25699), west coast of Lanyu Island, Taiwan, calcareous rock terraces, spray zone, coll. C.D. Schubart & H.-C. Liu, 20–21 September 1999; 2 males (23.0 × 18.3 mm, 16.7 × 13.0 mm) (NMMBA 3504 a), coll. Hsiang-Chiau- Wan, Kenting, Pingtung County, Taiwan, coll. C.C. Li, 23 August 2012 ; 2 females (21.0 × 15.7 mm, 20.0 × 14.9 mm) (ZRC 2012.0958), Siatanzai, Kenting, Pingtung County, 21°55′55.8″N 120°44′37.4″S, Taiwan, coll. J.-H. Lee & W.-J. Wang, 6 August 2012 ; 1 male (17.1 × 13.0 mm), 1 female (20.5 × 15.6 mm) (NMNS), Siatanzai, Kenting, Pingtung County, 21°55′36.6″N 120°44′21.8″S, Taiwan, coll. J.-H. Lee & W.-J. Wang, 17 August 2012 ; 1 male (18.1 × 13.9 mm) (ZRC 2012.0959), Siatanzai, Kenting, Pingtung County, 21°55′36.6″N 120°44′21.8″S, Taiwan, coll. J.-H. Lee & W.-J. Wang, 31 August 2012 ; 1 male (17.8 × 13.9 mm), 1 ovigerous female (18.8 × 14.2 mm) (ZRC 2012.0960), Siatanzai, Kenting, Pingtung County, 21°55′36.6″N 120°44′21.8″S, Taiwan, coll. J.-H. Lee & W.-J. Wang, 31 August 2012 ; 1 female (22.3 × 16.6 mm) (ZRC 2012.0961), Hsiang-Chiau- Wan, Kenting, Pingtung County, Taiwan, coll. P.K.L. Ng & C.-W. Lin, 1 October 2012 . Others: JAPAN – 1 male (16.1 × 12.4 mm) (RUMF-ZC-1351), Gazuda Beach, Hateruma Island, Ryukyu Islands, coll. Y. Fujita, 2 May 2009 ; 2 males (15.5 × 11.1 mm, 13.2 × 9.9 mm) (RUMF-ZC-1386), beside Hateruma Port, Hateruma Island, Ryukyu Islands, coll. Y. Fujita, 19 April 2009 ; 1 male (16.9 × 13.0 mm) (RUMF- ZC-2075), Dannu Beach, Yonagun Island, Ryukyu Islands, coll. Y. Fujita, 15 November 2007 ; 1 male (19.7 × 14.6 mm) (RUMF-ZC-2076), Honba Coast, Minamidaito Island, coll. Y. Fujita, 2 September 2008 ; 1 male (18.5 × 13.9 mm) (RUMF-ZC-2077), Honba Coast, Minamidaito Island, coll. Y. Fujita, 2 September 2008 ; 1 male (10.9 × 8.2 mm) (RUMF- ZC-2078), Ubama Beach, Yonaguni Island, Ryukyu Islands, coll. Y. Fujita, 16 November 2007 ; 1 male (17.2 × 12.8 mm) (RUMF-ZC-2079), Dannu Beach, Yonaguni Island, Ryukyu Islands, coll. Y. Fujita, 15 November 2007 ; 1 male (12.5 × 9.5 mm) (RUMF-ZC-2080), Dannu Beach, Yonaguni Island, Ryukyu Islands, coll. Y. Fujita, 15 November 2007 ; 1 female (16.9 × 12.9 mm) (RUMF-ZC-2082), Shimoji Island, Miyako Group, Ryukyu Islands, coll. Y. Fujita, 23 September 2012 ; 1 female (15.6 × 12.1 mm) (RUMF-ZC-2083), Shimoji Island, Miyako Group, Ryukyu Islands, coll. Y. Fujita, 23 September 2012 ; 1 female (18.0 × 13.1 mm) (RUMF-ZC-2089), Giza Banta, Okinawa Island, Ryukyu Islands, coll. T. Maenosono, 2007; 2 males (16.0 × 12.2 mm, 14.1 × 11.0 mm), 1 female (14.8 × 11.6 mm) (RUMF-ZC-2090), Kori Island, off Nakijin Village of Okinawa Island, Ryukyu Islands, coll. T. Maenosono, 9 June 2010 ; 2 males (17.5 × 13.7 mm, 17.4 × 12.9 mm), 1 female (15.7 × 12.1 mm) (RUMF-ZC-2104), Muigah, Miyako Island, Ryukyu Islands, coll. Y. Fujita, 4 May 2005 ; 6 males (largest 18.9 × 14.5 mm, smallest 14.3 × 10.8 mm), 5 females (largest 15.2 × 11.3 mm, smallest 8.3 × 7.1 mm) (ZRC), Muigah, Miyako Island, Ryukyu Islands, coll. Y. Fujita, 4 July 2005 ; 1 female (12.0 × 15.7 mm) (RUMF-ZC-819), Giza Banda, Yaese Town, Okinawa Island, Ryukyu Islands, coll. T. Maenosono, 22 May 2007 .

Diagnosis. Carapace transversely subovate, ca. 1.3 times broader than long; dorsal carapace, lateral branchial regions markedly swollen; external orbital tooth moderately oblique, forming slight angle posteriorly marking widest point of carapace, most prominent in larger specimens; front ca. 0.6 times carapace width, margin slightly to broadly concave in dorsal view, appears smooth but microscopically granular, with pair of prominent lateral swellings behind margin; supraorbital margin entire, semicircular; dorsal surface of cheliped carpus conspicuously granular; ambulatory legs relatively short; third ambulatory merus ca. 2.3 times longer than wide; fourth ambulatory merus similar, 2.2–2.3 times longer; third ambulatory propodus ca. 2.8 times longer than wide; fourth ambulatory propodus 2.4 times; male pleon moderately broad; somite 6 with divergent lateral margins, margins relatively evenly convex; somite 3 width 2.8 times basal width of telson; G1 relatively slender, weakly tapering to broadly convex subdistal shoulder; distally slender, strongly bent to 45° angle; distal chitinous process long, with dorsal margin concave, apex slightly flanged. (After Davie & Ng, 2013: 19).

Colour. “Carapace background colour of adult males varying from pale brown to a darker grey-green; females and smaller males mottled greyish white, sometimes yellowish. Upper surface of carapace and legs with some course blotches and streaks; a distinctive pattern of large dirty yellow to green blotches across anterior part of carapace. Chelae of adult males reddish-pink to purplish red overall, especially on dorsal surfaces and dactylus; smaller males and females with palm whitish to whitish-pink, dactylus always clearly tinged with red to pink in part or whole. Ocular peduncles similar to carapace; corneas light green to yellowish green.” (Davie & Ng, 2013: 20, fig. 3D–H).

Remarks. The taxonomy of this species has been treated and discussed by Davie & Ng (2013).

Biology. The species lives among supralittoral karst areas, usually under rocks or in crevices, often in exposed areas (Davie & Ng, 2013: 21). It occurs sympatrically with D. eurymerus and thus must have different ecological adaptations, but this has not been studied.

Distribution. Known only from Taiwan and Ryukyus, Japan (Davie & Ng, 2013).