Ctenus bayeri, Jager, 2012

Jäger, Peter, 2012, Asian species of the genera Anahita Karsch 1879, Ctenus Walckenaer 1805 and Amauropelma Raven, Stumkat & Gray 2001 (Arachnida: Araneae: Ctenidae), Zootaxa 3429 (1), pp. 1-63 : 39-40

Ctenus bayeri spec. nov.

Figs 39 , 163–169

Type material. Holotype male ( SMF), Laos, Champasak Province, Muang Bachieng, Pak Song, Bolaven Plateau , N 15°10'36.0'', E 106°14'15.2'', 1280 m altitude, pine tree plantation, at tree bark, by hand, by day, S. Bayer leg. 27.XI.2009.

Etymology. This species is named in honour of Steffen Bayer, who collected the holotype of this new species; name in genitive case.

Diagnosis. Medium-sized Ctenidae (total length male 12.1). Males are distinguished from those of other Ctenus spp. by (1) the strong tegular apophysis which extends distally beyond the embolus, conductor and alveolus margin, (2) the tiny and pointed RTA, and (3) the distally swollen palpal tibia ( Figs 163–165 ).

Description. Male (holotype). PL 6.3, PW 4.6, AW 2.5, OL 5.8, OW 3.9. Eye diameters and interdistances: AME 0.30, ALE 0.21, PME 0.40, PLE 0.36, AME–AME 0.13, AME–ALE 0.27, PME–PME 0.19, PME–PLE 0.30, AME–PME 0.05, ALE–PLE 0.11, clypeus AME 0.20, clypeus ALE 0.45. Palp and leg measurements: palp 8.2 (3.1, 1.3, 1.6, -, 2.2), I 18.3 (5.0, 2.5, 4.7, 4.4, 1.7), II 16.3 (4.5, 2.4, 3.9, 3.9, 1.6), III 14.1 (4.0, 2.0, 3.0, 3.6, 1.5), IV 18.8 (5.1, 2.1, 4.2, 5.7, 1.7). Leg formula 4123. Spination of palp and legs: palp 141, 100, 1101; femora I p021, d111, r112, II–III p112, d111, r 112, IV p112, d111, r002; patellae 101; tibiae I p010, d011, r110, v22222, II entire cheliceral furrow. Retromargin of chelicerae close to fang base with 7–9 bristles. Sparse scopula on all tarsi and metatarsi I–II. Leg claw I and IV with 5 secondary teeth. Position of tarsal organ: I 0.78, II 0.78, III 0.65, IV 0.65.

Palp as in diagnosis ( Figs 163–165 ). RTA arising from tibia slightly ventrally. Cymbium tip bluntly conical, retro-proximally with distinct blunt extension; proximal cymbium with shallow pocket. Embolus arising at 8- o’clock-position, short, its tip situated prolatero-distally; its base with membranous seam. Conductor arising at 11- o’clock-position prolatero-distally. Tegular apophysis arising centrally from tegulum, in ventral view bent hooklike distally, distinctly excavated on prolateral side.

Colour ( Figs 166–169 ). Reddish-brown with light and dark pattern. Dorsal prosoma with distinct light median band consisting of white dense hairs, and distinctly marked fovea. Sternum, ventral coxae dark yellowish-brown without pattern; labium and gnathocoxae darker with light distal parts. Chelicerae as dorsal prosoma with dark distal half. Legs reddish-brown without distinct pattern. Dorsal opisthosoma with light area and dark lateral patches in anterior half; posterior half with dark indistinct chevrons. Lateral opisthosoma dotted. Ventral opisthosoma dark with two posteriorly converging rows of white patches consisting of white hairs, median field with one pair of white patches close to epigastric furrow; epiandrium and muscle sigilla light. Anterior lateral spinnerets laterally dark, posterior lateral and median spinnerets and anal tubercle light.

Female. Unknown.

Distribution. Known only from the type locality ( Fig. 39 : 12).

Figures

FIGURE 39. Records of Ctenus spp. in South and Southeast Asia. 1 Between Chitre and Chandrung, Nepal. 2–5 Burma (2

FIGURES 163–165. Ctenus bayeri spec. nov., holotype male from Pak Song, Champasak, Laos, left male palp (163 prolateral; 164 ventral; 165 retrolateral).

FIGURES 166–169. Ctenus bayeri spec. nov., holotype male from Pak Song, Champasak, Laos, habitus (166 dorsal; 167 ventral; 168 lateral; 169 frontal).