Ryuthela motobu, Xu & Liu & Ono & Chen & Kuntner & Li, 2017

Xu, Xin, Liu, Fengxiang, Ono, Hirotsugu, Chen, Jian, Kuntner, Matjaž & Li, Daiqin, 2017, Targeted sampling in Ryukyus facilitates species delimitation of the primitively segmented spider genus Ryuthela (Araneae: Mesothelae: Liphistiidae), Zoological Journal of the Linnean Society 181, pp. 867-909 : 888-890

RYUTHELA MOTOBU SP. NOV.

urn:lsid:zoobank.org:act:AF642340-2C19-4DE9-B38E-793C3221A261

Holotype: Male (XUX-2014-090, matured 6 September 2014 at CBEE, College of Life Sciences , Hubei

University ), collected at Jahana , Motobu-cho, Okinawajima island, Japan, 26.68°N, 127.90°E, 77 m a.s.l., 11 May 2014, by D. Li and B. Wu .

Paratypes: Five females and one juvenile [XUX-2014- (085-089/091)], collected at the same locality as the holotype , two females (XUX-2014-092/098), collected at Yamazato , Motobu-cho, Okinawajima island, Japan, 26.67°N, 127.91°E, 143 m a.s.l., 11 May 2014, by D. Li and B. Wu .

Etymology: The species epithet, a noun in apposition, refers to the type locality.

Diagnosis: Male R. motobu sp. nov. can be distinguished from R. nishihirai s.s. by the short and curved contrategular spine ( Fig. 8A, C, E); from R. iheyana by the larger marginal apophysis of tegulum ( Fig. 8C–E); from other Ryuthela species by the short and blunt distal contrategulum, and the narrow basal part of embolus ( Fig. 8B, D, E). Females of R. motobu sp. nov. can be distinguished from R. henoko sp. nov. by the receptacular clusters with bases separated from each other and from the other Okinawajima island species by the receptacular clusters that are longer than their width ( Fig. 8F–N). However, R. motobu sp. nov. can also be diagnosed from R. nishihirai s.s. by the following unique nucleotide substitutions in the standard DNA barcode alignment: G (1), T (16), C (26), A (58), C (76), T (109), C (115), G (119), A (157), A (160), T (173), G (181), C (239), G (241), T (247), C (256), A (278), A (304), C (313), C (332), T (337), T (343), T (352), G (358), A (445), T (475), C (484), T (494), A (496), T (533), G (535), C (571), T (577), C (592), T (601), C (604), G (607), G (619) and differs from all other Ryuthela species on Okinawajima island by the following unique nucleotide substitutions in the standard DNA barcode alignment: A (58), C (76), G (181), T (337), T (533), G (535), G (619).

Description: Male (holotype). Carapace light brown; opisthosoma brown, with dark brown tergites; sternum narrow, much longer than wide; a few long pointed hairs running over ocular mound in a longitudinal row; chelicerae robust with promargin of cheliceral groove with 11 denticles of variable size; legs with strong hairs and spines; opisthosoma with 12 tergites, the fourth largest; 7 spinnerets. Measurements: BL 11.50, CL 6.15, CW 5.20, OL 6.60, OW 5.00; ALE> PLE> PME> AME; leg I 16.45 (4.10 + 1.25 + 3.60 + 4.90 + 2.60), leg II 19.80 (5.30 + 1.90 + 4.10 + 5.50 + 3.00), leg III 20.00 (5.20 + 1.60 + 3.90 + 5.60 + 3.70), leg IV 28.00 (6.70 + 2.20 + 5.50 + 8.80 + 4.80).

Palp. Prolateral side of paracymbium unpigmented and unsclerotized; numerous setae and spines at the tip of paracymbium ( Fig. 8A). Prolateral contrategulum with a short and curved spine and numerous denticles on proximal margin ( Fig. 8A, B); the distal part of contrategulum blunt ( Fig. 8E); tegulum with a large smooth marginal apophysis ( Fig. 8C, E); embolus with a narrow basal part ( Fig. 8C–E).

Female. Carapace and opisthosoma brown; tergites slightly dark brown; a few long pointed hairs running over ocular mound in a longitudinal row; chelicerae robust with promargin of cheliceral groove with 11–15 strong denticles of variable size; legs with strong hairs and spines; opisthosoma with 12 tergites, the fourth largest; 7 spinnerets. Measurements: BL 10.90– 14.80, CL 5.00–6.90, CW 4.00–5.80, OL 6.10–9.40, OW 5.00–7.30; ALE> PLE> PME> AME; palp 9.20 (2.90 + 1.40 + 2.20 + 2.70), leg I 11.20 (3.50 + 1.90 + 2.25 + 2.35 + 1.20), leg II 10.95 (3.40 + 1.80 + 2.00 + 2.30 + 1.45), leg III 10.55 (3.15 + 1.85 + 2.15 + 2.10 + 1.30), leg IV 17.55 (4.80 + 2.40 + 3.15 + 4.70 + 2.50).

Female genitalia. A pair of receptacular clusters along the anterior margin of bursa copulatrix; their length longer than their width in dorsal view ( Fig. 8F–H, L); without genital stalks ( Fig. 8F–N).

Distribution: Okinawajima island (Jahana and Yamazato, Motobu-cho), Okinawa Prefecture, Japan.