Ctenus martensi, 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 : 13-14

Ctenus martensi spec. nov.

Figs 39–46

Type material. Holotype male ( SMF), Nepal, Parbat district , between Chitre and Chandrung, Chitre side of the pass, Tsuga-Rhododendron, 2880–2900 m altitude, Martens & Ausobsky leg. 4./ 7.V.1980 . Paratype. 1 male ( SMF), with same data as for holotype .

Etymology. The specific epithet honours Jochen Martens, my former PhD supervisor, who not only collected the type material of this species from Nepal, but also collected a wealth of material from many arthropod groups; noun (name) in genitive case.

Diagnosis. Small Ctenidae (total length male 9.5–9.9). Distinguished from other Ctenus spp. by cymbial tooth on retromargin, the uniquely U-shaped RTA and its proximal arising point as well as the tegular apophysis distinctly concave prolaterally ( Figs 40–42 ).

Description. Male (holotype). PL 5.1, PW 3.8, AW 2.0, OL 4.4, OW 2.5. Eye diameters and interdistances: AME 0.22, ALE 0.21, PME 0.28, PLE 0.28, AME–AME 0.12, AME–ALE 0.21, PME–PME 0.10, PME–PLE 0.31, AME–PME 0.13, ALE–PLE 0.09, clypeus AME 0.10, clypeus ALE 0.31. Palp and leg measurements: palp 6.4 (2.3, 0.9, 1.2, -, 2.0), I 15.1 (4.0, 1.9, 3.8, 3.6, 1.8), II 14.0 (3.8, 1.9, 3.4, 3.3, 1.6), III 12.9 (3.4, 1.8, 3.0, 3.3, 1.4), IV 16.6 (4.2, 1.8, 3.9, 4.9, 1.8). Leg formula 4123. Spination of palp and legs: palp 141, 100, 1001; femora I p01(0)2, d111, r111, II p112, d111, r 111, III p112, d111, r012, IV p112, d111, r002; patellae I 1(0)01, II–IV 101; tibiae I p010, d001, r110, v22222, II p110, d001, r110, v22222, III–IV p11, d011, r11, v222; metatarsi I–II p111, r111, v222, III p112, d010, r112, v222, IV p112, d010, r112, v2122. Chelicerae with 3 promarginal, 3 retromarginal teeth, and without denticles. Retromargin of chelicerae close to fang base with 1 bristle. Ventral tarsi and metatarsi I–II with sparse scopula. Leg claws I with 7, leg claw IV with 9 secondary teeth. Tarsal organs: I 0.80, II 0.79, III 0.70, IV 0.70.

Palp as in diagnosis ( Figs 40–42 ). Cymbium tip slightly conical, cymbial retromargin with slight ventral spermophor dorsally, subdistally with tiny slit at proximal side. Embolus base with indistinct membranous seam. Tegular apophysis elongated, about twice as long as wide, distinctly excavated prolaterally.

Colour ( Figs 43–46 ). Yellowish- to reddish-brown. Dorsal prosoma with faint radial markings, distinctly marked fovea and black circles around eyes. Sternum, ventral coxae, labium and gnathocoxae yellowish-brown without pattern. Chelicerae yellowish-brown without distinct pattern. Legs yellowish-brown with distal segments darker, partly with indistinct diffused black colour. Dorsal opisthosoma with light heart region. Lateral opisthosoma with spots and striae. Ventral opisthosoma light with dark median field and light patches within. Spinnerets and anal tubercle light.

Female. Unknown.

Variation. Paratype male: PL 5.4, OL 4.6, with ventral opisthosoma lighter.

Distribution. Known only from the type locality ( Fig. 39 : 1).

The following two species exhibit a unique RTA tip modification: the more or less complex tip (“apical spur” sensu F.O. Pickard-Cambridge 1902; “thin and transparent chitinous appendage” sensu Gravely 1931) is fixed on a predetermined breaking point; this feature is also known for emboli in other spiders, e.g. in Argiope Audouin 1826 ( Jäger 2012) . When one of these structures was touched in the preserved holotype of C. cladarus spec. nov., it broke promptly. In the right palp of the holotype of C. ramosus it was already broken. Based on the illustrations by Tikader and Malhotra (1981) the following species could also possess such a breakable RTA tip: C. ceylonensis F.O. Pickard-Cambridge 1897 , C. bomdilaensis Tikader & Malhotra 1981 , C. himalayensis Gravely 1931 and C. sikkimensis Gravely 1931 . Silva-Dávila (2003) considered this character in her cladistic analysis as matrix character #13.

Figures

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

FIGURES 40–42. Ctenus martensi spec. nov., holotype male from Nepal, left male palp (40 prolateral, 41 ventral, 42 retrolateral). C—conductor, E—embolus, ME—membranous extension of embolus, here developed as short seam, SD—sperm duct, TA—tegular apophysis.

FIGURES 43–46. Ctenus martensi spec. nov., holotype male from Nepal, habitus (43 dorsal, 44 ventral, 45 frontal, 46 lateral).