A taxonomic monograph of the liphistiid spider genus Heptathela, endemic to Japanese islands Author Xu, Xin Author Ono, Hirotsugu Author Kuntner, Matjaz Author Liu, Fengxiang Author Li, Daiqin text ZooKeys 2019 888 1 50 http://dx.doi.org/10.3897/zookeys.888.34494 journal article http://dx.doi.org/10.3897/zookeys.888.34494 1313-2970-888-1 B995C05697EC41A49012B58F9D3AFDC1 F8810409F4DA5A43BF94417F5D40DECE Heptathela helios Tanikawa & Miyashita, 2014 Fig. 24 Heptathela helios Tanikawa & Miyashita, 2014: 68 (holotype: male (NSMT-Ar 12851), from Kunigami-son, Okinawajima, Japan, collected by A. Tanikawa on 26 May 2010, matured on 9 September 2012, deposited in NMNS, examined). Diagnosis. Males of H. helios can be distinguished from those of all other Okinawa group Heptathela species by the serrated contrategulum margin and the hooked tegular marginal apophysis, the ovate, indistinctly rugose conductor with a poorly serrated margin ( Fig. 24 D-G ). Females of H. helios can be distinguished from those of all other Heptathela species by the receptacular clusters with the inner ones being smaller than the laterals, and the laterals with numerous small granulate tubercula ( Fig. 24 H-M ). H. helios can also be diagnosed from all other Okinawa group Heptathela species by the following unique nucleotide substitutions in the standard DNA barcode alignment: T (11), T (35), G (47), A (56), C (59), A (95), T (104), A (131), T (140), T (179), C (188), C (215), G (221), C (242), C (266), C (273), C (299), C (300), C (304), T (359), G (380), T (413), A (422), T (425), T (431), G (479), G (480), G (491), G (506), C (543), T (546), G (548), C (551), C (596), T (662). Figure 24. Male and female genital anatomy of Heptathela helio Tanikawa & Miyashita, 2014 A-G 2440A (short for XUX-2012-440A) H, K 2432 I, L 2434 J, M 2437 A palp prolateral view B palp ventral view C palp retrolateral view D-G palp distal view H-J vulva dorsal view K-M vulva ventral view. Scale bar: 0.5 mm. Description. Male. Carapace and opisthosoma brown, with dark brown tergites; cheliceral groove with 14 denticles; tergites closed to each other; seven spinnerets. Measurements: BL 9.88, CL 5.30, CW 4.81, OL 4.58, OW 2.92; ALE> PLE> PME> AME; leg I 16.56 (4.55 + 1.90 + 3.48 + 4.33 + 2.30), leg II 17.19 (4.50 + 2.00 + 3.34 + 4.68 + 2.67), leg III 18.35 (4.35 + 1.97 + 3.40 + 5.53 + 3.10), leg IV 23.37 (5.52 + 2.10 + 4.47 + 7.48 + 3.80). Palp . The bulb of the two male specimens relatively distorted. Prolateral side of paracymbium unpigmented and unsclerotised, numerous setae and spines at the tip of paracymbium ( Fig. 24 A-C ). Contrategulum with a serrated margin ( Fig. 24E, G ). Tegulum with a dentate dorsal extension of terminal apophysis ( Fig. 24F, G ), blunt terminal and hook-like marginal apophysis ( Fig. 24D, F, G ). Conductor sclerotised, ovate, and wide, with indistinct rugae ( Fig. 24 E-G ). Embolus sclerotised, with a wide opening, the distal margin slightly sclerotised, and with a saddle-shaped margin in the retrolateral view ( Fig. 24 D-G ). Females ( N = 7). Carapace and opisthosoma colour as in male; cheliceral groove with 12-14 pronounced denticles; opisthosoma with 12 well-separated tergites; seven spinnerets. Measurements: BL 11.70-14.45, CL 5.29-6.70, CW 4.29-5.81, OL 6.54-8.18, OW 4.70-6.63; ALE> PLE> PME> AME; palp 12.29 (4.20 + 2.03 + 2.63 + 3.43), leg I 14.31 (4.51 + 2.40 + 2.65 + 3.08 + 1.67), leg II 14.04 (4.25 + 2.35 + 2.53+ 3.11 + 1.80), leg III 13.75 (3.92 + 2.40 + 2.48 + 2.67 + 2.28), leg IV 21.77 (5.90 + 2.88 + 3.75 + 6.11 + 3.13). Female genitalia . A pair of depressions on the ventro-lateral part of genital atrium ( Fig. 24 K-M ). Paired receptacular clusters along the anterior margin of bursa copulatrix, divided into two parts, inner receptacular clusters smaller than laterals, laterals with several small tubercula, with short genital stalks ( Fig. 24 H-M ). Remarks. We identified the specimens collected from Ginama Dam, Okinawa, as H. helios based on evidence from morphology and COI barcode genetic distance compared with the male holotype and paratype (NSMT-Ar 12851, NSMT-Ar 12855) of H. helios in Tanikawa and Miyashita (2014) . K2P and p -distances between Ginama Dam specimens and the holotype (NSMT-Ar 12851) were 3.2-3.4% and 3.1-3.3%, respectively, and those between Ginama Dam specimens and the paratype (NSMT-Ar 12855) were 1.8-2.1% and 1.7-2.1%, respectively. Material examined. JAPAN · 2 ♂♂, 8 ♀♀; Okinawa-ken, Kunigami-son, Ginama Dam; 26.84N , 128.26E ; alt. 150 m; 24 December 2012; D. Li, F.X. Liu and X. Xu leg.; XUX-2012-432 to 440C. Distribution. The species is endemic to the Japanese island Okinawajima ( Fig. 1C ).