Ctenus pingu, Jäger, Peter & Minn, Myin Zu, 2015

Jäger, Peter & Minn, Myin Zu, 2015, New species in the family Ctenidae Keyserling, 1877 from high altitude habitats in Myanmar, with the first case of penetration of the female’s cuticle by a male in the RTA-clade (Arachnida: Araneae: Ctenidae), Zootaxa 3994 (2), pp. 235-252 : 247-250

Ctenus pingu spec. nov.

Figs 51–63

Type material. MYANMAR: Chin State: Holotype male, Nat Ma Taung National Park, Kampetlet-Mindat road, 21°12'33.8''N, 94°01'26.8''E, 2150 m, disturbed primary forest, by hand, at day and night, P. Jäger leg. 9 & 11 May 2014 ( SMF). Paratype: 1 female, with same data as for holotype ( SMF).

Etymology. The species name is derived from “p ng kuu”, the Burmese name for “spider”; name in apposition.

Diagnosis. Medium-sized Ctenidae (total length male 12.3, female 11.9). Male palpal organs are similar to those of C. ramosus , C. cladarus and C. natmataung spec. nov. in having similar arrangement of bulbal structures as well as a similar RTA (see note below). Males of this new species can be distinguished from those of C. ramosus by the roughly triangular shape of the proximal part of the tegular apophysis and the distinctly longer embolus reaching into retrolateral half of tegulum, and from those of C. cladarus and C. natmataung spec. nov. by the subquadrangular median membranous extension of the embolus (more or less pointed in C. cladarus and C. natamataung spec. nov.), by the distal part of the tegular apophysis narrow and constricted proximally (straight and wider in C. cladarus , constricted and wider in C. natmataung spec. nov.) and additionally from C. natmataung spec. nov. by the distal margin of the proximal part of the tegular apophysis oblique (transversal in C. natmataung spec. nov.) ( Fig. 52 ). The female copulatory organ is similar to that of C. cladarus in having the anterior part of epigyne not as distinctly narrower than in many other Ctenus spp. (e.g. in C. natmataung spec. nov., C. ramosus , C. robustus , C. lishuqiang ) ( Fig. 55 ), but can be distinguished by the distinctly larger chamber I of the spermathecae, the irregular anterior outline of the spermathecae and the outline of chamber II much more pronounced ( Fig. 57 ).

Note. Most likely, males of C. pingu spec. nov. possess, as do C. cladarus , C. natmataung spec. nov. and C. ramosus , an additional distal part at the RTA, which breaks easily during the copulation process. Since this structure was not present in the only male available, examination of further material would be required to show whether differences in this part will contribute to species diagnosis.

Description. Male. PL 6.6, PW 5.0, AW 2.7, OL 5.7, OW 3.6. Eye diameters and interdistances: AME 0.32, ALE 0.21, PME 0.39, PLE 0.30, AME–AME 0.13, AME–ALE 0.17, PME–PME 0.33, PME–PLE 0.39, AME– PME 0.12, ALE–PLE 0.10, clypeus height at AME 0.18, clypeus height at ALE 0.53. Palp and leg measurements: palp 7.3 (2.8, 1.2, 1.2, -, 2.1), I 19.9 (5.2, 2.3, 5.4, 5.1, 1.9), II 18.9 (5.2, 2.4, 4.9, 4.7, 1.7), III 16.4 (4.7, 2.1, 4.0, 4.1, 1.5), IV 21.2 (5.5, 2.3, 5.1, 6.2, 2.1). Leg formula 4123. Spination of palp and legs: palp 141, 100, 1111; femora I p012, d111, r111, II p112, d111, r111, III p112, d111, r112, IV p112, d111, r002; patellae I 101(0), II–IV 101; tibiae I p010, r11(0)0, v22222, II p011, r110, v2222, III–IV p11, d111, r11, v222; metatarsi I–II v222, III–IV p111, d012, r111, v222. Chelicerae with 3 promarginal, 4 retromarginal teeth, and 1–2 denticles in cheliceral furrow. Retromargin of chelicerae close to fang base with 8–9 bristles. Sparse scopula on all tarsi and metatarsi, in metatarsi III–IV only in distal part. Coxae ventrally with short (some stronger and stout) setae leaving a proximal longitudinal patch free of setae.

Palp as in diagnosis ( Figs 51–54 ). RTA with relatively broad base, converging only slightly distally, with small outgrowth ventro-distally. Cymbium tip conical, retro-proximally with small pit( Fig. 53 ). Embolus arising at 7:30- to 8-o’clock-position from tegulum, semicircular in ventral view, with broad base, its tip with small indentation and situated in distal half of tegulum. Conductor arising at 12-o’clock-position subdistally. Tegular apophysis arising at 5:30-o’clock-position from tegulum, shallowly excavated on dorsal side.

Colouration ( Figs 58–59 ). Light reddish-brown with dark markings. Prosoma dorsally with light median band, widest behind eyes, laterally with dark bands, the latter interrupted by light striae on each side between head and thoracic part, and with longitudinal narrow light band; fovea distinct, dark in posterior third. Sternum and ventral coxae yellowish-brown without pattern; labium and gnathocoxae brown with lighter distal parts. Chelicerae dark reddish-brown with light lateral humps proximally. Legs brown, distally darker, femora ventrally lighter. Opisthosoma dorsally with large light median area and lateral dark patches in anterior half; posterior half with 4–5 pairs of dark spots; laterally with scarcely spotted; ventrally dark with four posteriorly converging rows of white patches consisting of white hairs; epiandrum and muscle sigilla light.

Female. PL 6.1, PW 4.4, AW 3.0, OL 5.8, OW 3.5. Eye diameters and interdistances: AME 0.27, ALE 0.24, PME 0.37, PLE 0.32, AME–AME 0.20, AME–ALE 0.20, PME–PME 0.39, PME–PLE 0.40, AME–PME 0.13, ALE–PLE 0.16, clypeus height at AME 0.15, clypeus height at ALE 0.53. Palp and leg measurements: palp 6.4 (2.2, 1.1, 1.5, -, 1.6), I 14.8 (4.1, 2.2, 4.0, 32, 1.3), II 14.0 (4.0, 2.1, 3.6, 3.1, 1.2), III 12.6 (3.6, 1.8, 3.0, 3.0, 1.2), IV 16.7 (4.5, 1.8, 4.0, 4.8, 1.6). Leg formula 4123. Spination of palp and legs: palp 131, 100, 1111, 1013; femora I p003, d111, r111, II p112, d111, r 111, III p112, d111, r112, IV p112, d111, r002; patellae I–II 0 0 0, III–IV 101; tibiae I v22222, II p001, r001, v2222, III–IV p11, d111, r11, v222; metatarsi I v222(1), II v222, III–IV p111, d012, r111, v222. Chelicerae with 3 promarginal, 4 retromarginal teeth, and with 4 denticles in cheliceral furrow. Retromargin of chelicerae close to fang base with 4–5 thin bristles. Ventral tarsi and metatarsi I–II with sparse scopula, metatarsi only distally. Leg claw I with 5 secondary teeth.

Copulatory organ as in diagnosis ( Figs 55–57 ). Epigynal field as long as wide, with two pairs of slit sensilla latero-medially. Median plate roughly trapezoid, rounded posteriorly, with one pair of lateral longitudinal furrows; epigynal teeth arising at posterior part. Internal duct system with lateral folds diverging posteriorly, anteriorly bent. Spermathecae longitudinal, chamber II much smaller than chamber I, fertilisation ducts arising posteriorly, mediad.

Colouration ( Figs 60–62 ). As in male, but generally slightly darker. Light striae between head and thoracical part absent. Coxae ventrally with longer setae. Femora ventrally not distinctly lighter. Opisthosoma much darker, ventral sigilla patches fused and consisting of light hairs. For colouration pattern of a living specimen see Fig. 62 . Note the continuous narrow light band within the dark lateral band of the prosoma dorsally. This character might prove diagnostic if it is present in a larger series of specimens.

Distribution. Known only from the type locality, Mt Victoria from elevations of 2150 m ( Fig. 63 : yellow circle).

Figures

FIGURE 63. Distributional records of Ctenidae treated in this paper. Large Map: Records at Nat Ma Taung (= Mt Victoria). Red triangles— Ctenus cladarus, yellow circle— C. pingu spec. nov., green squares— C. natmataung spec. nov., white arrowsummit. White numbers indicate elevation [m]. Inset: Location of Mt Victoria (orange drop), and Mt Popa (blue cross; Anahita popa spec. nov., 1250 m).

FIGURES 51 – 57 Ctenus pingu spec. nov., holotype male (51 – 54) and female paratype (55 – 57) from Mt Victoria, Myanmar, copulatory organs (51 palp, prolateral; 52 palp, ventral; 53 palp, retrolateral; 54 embolus tip, ventral; 55 epigyne, ventral; 56 epigyne, posterior; 57 vulva, dorsal). I + II—two chambers of spermathecae, chamber II functionally between chamber I and fertilisation duct; CP—cymbial pit.

FIGURES 58 – 62 Ctenus pingu spec. nov., holotype male (58 – 59) and female paratype (60 – 61) from Mt Victoria, Myanmar, habitus (58, 60, 62 dorsal; 59, 61 ventral).