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

RYUTHELA BANNA View in CoL SP. NOV.

urn:lsid:zoobank.org:act:60FDE0FA-EFC8-436E-8A95-598E4EBD7443

Holotype: Male (XUX-2013-214), collected at Mt. Banna dake, Ishigakijima island, Okinawa Prefecture, Japan, 24.37°N, 124.16°E, 216 m a.s.l., 9 July 2013, by D. Li and B. Wu. GoogleMaps

Paratypes: Two females (XUX-2013-211/213), collected at the same locality as holotype GoogleMaps ; three females and three juveniles [XUX-2013-(216–221)], collected at Mt. Nose dake, Ishigakijima island, Okinawa Prefecture, Japan, 24.37°N, 124.14°E, 125 m a.s.l., 9 July 2013, by D. Li and B. Wu GoogleMaps .

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

Diagnosis: Male of R. banna sp. nov. is similar to R. ishigakiensis s.s. and R. hirakubo sp. nov., but it can be distinguished from them by the short and curved contrategular spine, and the fewer denticles at the basal part of the contrategulum ( Fig. 16A, D, E); from R. ishigakiensis s.s. by the relative location between the basal part of the embolus and the terminal apophysis of the tegulum ( Fig. 16F); and from R. hirakubo sp. nov. by the fusion of the outer smooth margin of the upper edge and the lower at the distal part of contrategulum ( Fig. 16F); it differs from other Ryuthela species by the contrategulum with two edges, the wider basal embolus ( Fig. 16C, E, F) and the wide separation of the tegulum from the contrategulum ( Fig. 16C, F). Female genitalia of R. banna sp. nov. lack diagnostic characters from other species on Ishigakijima and Iriomotejima islands ( Fig. 16G–L). However, R. banna sp. nov. can be diagnosed from all other Ryuthela species on Ishigakijima island and Iriomotejima island by the following unique nucleotide substitutions in the standard DNA barcode alignment: G (4), T (61), G (64), G (85), T (157), C (226), T (310), T (328), G (349), C (367), A (376), C (439), G (454), T (533), A (559).

Description: Male (holotype). Carapace and opisthosoma yellow brown; tergites darker brown; sternum narrow, nearly twice as long as wide; a few long pointed hairs running over ocular mound in a longitudinal row; chelicerae robust with promargin of cheliceral groove containing 14 vestigial denticles of variable size; legs with strong hairs and spines; opisthosoma with 12 tergites; 8 spinnerets. Measurements: BL 13.00, CL 6.50, CW 5.70, OL 5.60, OW 4.35; ALE> PLE> PME> AME; leg I 18.85 (5.00 + 2.30 + 3.60 + 5.30 + 2.65), leg II 20.05 (5.15 + 2.55 + 3.70 + 5.70 + 2.95), leg III 21.45 (5.30 + 2.30 + 3.70 + 6.65 + 3.50), leg IV 27.45 (6.50 + 2.80 + 5.00 + 8.55 + 4.60).

Palp. Prolateral paracymbium unpigmented and unsclerotized, numerous setae and spines at the tip of paracymbium ( Fig. 16A); contrategulum with a short and curved spine and fewer denticles at the basal part of contrategulum ( Fig. 16A, D, E); the outer smooth margin of the upper edge and the lower fused at the distal part of contrategulum, and lower edge of contrategulum blunt ( Fig. 16E, F); the distal part of terminal apophysis of tegulum thumb-shaped in retrolateral view ( Fig. 16C, F); embolus with a wide basal part ( Fig. 16E, F); in retrolateral view, the terminal apophysis of tegulum is located at two thirds of the basal embolus ( Fig. 16F).

Female. Coloration similar to that of the male; chelicerae robust with promargin of cheliceral groove containing 13–14 strong denticles of variable size; legs and opisthosoma as in the male; 7–8 spinnerets. Measurements:

BL 10.90–15.50, CL 5.28–7.83, CW 4.11–6.90, OL 5.60– 8.28, OW 4.35–6.25; ALE> PLE> PME> AME; palp 13.81 (4.70 + 2.58 + 2.88 + 3.65), leg I 15.35 (4.70 + 2.4 0 + 3.25 + 3.30 + 1.70), leg II 15.78 (4.70 + 2.68 + 2.80 + 3.60 + 2.00), leg III 16.51 (4.25 + 2.88 + 2.70 + 4.20 + 2.48), leg IV 22.80 (6.10 + 2.50 + 4.30 + 6.40 + 3.50).

Female genitalia. A pair of small, ball-shaped receptacular clusters along the anterior margin of bursa copulatrix, basally separated from each other, with many or with unclear granula in ventral view ( Fig. 16G–L).

Distribution: Ishigakijima island (Mt. Banna dake, Mt. Nose dake), Okinawa Prefecture, Japan.