Sperchonopsis orientalis n. sp.

(Fig. 6A–E)

Type series. Holotype female, dissected and slide mounted, Mahua stream at crossing with main road, Crocker Range, Borneo, Malaysia, 5°45.225 N, 116°26.085 E, alt. 752 m asl., 22-ix-2012 (RMNH). Paratype: one female, same data as holotype (RMNH); one female, stream Kemantis, Sayap, Mt. Kinabalu, Borneo, Malaysia, 6° 0 9.841 N 116° 33.936 E, alt. 928 m asl, 16-ix-2012 (bar-coded, RMNH).

Diagnosis (Male unknown). Colour yellow; idiosoma slender (length/width ratio 1.5); mid dorsum with a pair of elongate platelets.

Description. Female: Colour yellow. Glandularia enlarged, mid dorsum with a pair of elongate plates (Fig. 6A); integument papillate. Coxal field: tips of Cx-I projecting and covered by numerous setae. Genital field: Ac-1- 2 longish, Ac-3 roundish. Excretory pore surrounded by a sclerotized ring. Capitulum with rostrum slightly shorter than base (Fig. 6E). Palp: P2 with a long ventrodistal projection bearing 2 setae, P4 with a ventral projection close to segment base, bearing 2 setae (Figs. 6C–D).

Measurements— Idiosoma (ventral view: Fig. 6B) length 640 (664), width 420 (478); distance between anterior tip of Cx-I and posterior margin of Cx-IV 347, Cx-III width 423; genital flap length 102, width 37, length Ac-1–3: 27–31, 28–31, 26–27. Capitulum ventral length 200; chelicera total length 195; palp: total length 363–369, dorsal length/height, dorsal length/height ratio: P1, 33/43, 0.77; P2, 105/54, 1.94; P3, 103–105/45–48, 2.2–2.3; P4, 88–91/27–29, 3.2–3.3; P5, 34/15, 2.3; length P2/P4 ratio 1.19. Legs: dorsal length of I-leg-1–6: 47, 63, 69, 98, 109, 109.

Male: unknown.

Etymology. Named after the Oriental fauna region.

Remarks. The specimens examined from Borneo agree in general morphology of idiosoma and palps with Sperchonopsis verrucosa (Protz, 1896), a species widely distributed in the Holarctic and Oriental regions. The latter species differs in the brownish colour (sometimes with bluish sclerotized parts) and in more stout idiosoma (length/width ratio <1.5, data taken from Di Sabatino et al. 2010). These small differences obviously do not reflect the genetic distance as the molecular distance between a Sperchonopsis orientalis n. sp. specimen from Borneo and S. verrucosa from The Netherlands were found to be high (18.8% in COI). These high divergence values suggest a long independent evolutionary history of these species.

Wiles (1999) reported Sperchonopsis verrucosa from several sites in the catchment area of the Rivers Temburong and Belalong in Brunei Darussalem, without discussion of differences with the original description. Most probably his specimens refer to S. orientalis n. sp. Further, all Oriental records of Sperchonopsis verrucosa need revision, at best with application of molecular techniques.

Distribution. Borneo.