Trachelas gigapophysis, Zhang, 2017

Zhang, Feng, 2017, Four new species of the genus Trachelas L. Koch, 1872 and the first record of T. vulcani Simon, 1896 from South-West China (Araneae: Trachelidae), Zootaxa 4324 (1), pp. 23-49 : 38-42

Trachelas gigapophysis sp. n.

Figs 13–15

Type material. Holotype: ♂, CHINA: Guizhou Province: Zunyi City, Suiyang County, Kuankuoshui National Nature Reserve , Kuankuoshui Reservoir (28°12.473′N, 107°10.378′E), 1435m a.s.l., 4 June 2010, leg. Zongxi Li . Paratypes: 1♂, same data as holotype ; 3♂, Sichuan Province: Ya’an City, Mengding Mountain (30°04.286′N, 103°02.555′E), 1213m a.s.l., 13 May 2012, leg. Kaiyi Xu, Luyu Wang and Dong Wang. All specimens are deposited in MHBU .

Etymology. The specific name, formed from the Latin giga (giant) and the English apophysis, refers to the giant dorsal tibial apophysis of the male palp.

Diagnosis. Among all the Old World Trachelas species, the new species resembles T. brachialis sp. n. in having two DTAs, but can be distinguished from it by: 1) the large DTA with two weak nodes, like a bamboo stem, and with blunt tip, whereas with a smooth surface and sharp tip in the latter species; 2) the small DTA is not spineshaped as in T. brachialis sp. n., but larger, broad and blunt; 3) embolus straight and bifurcated, whereas arm-like and twisted in the latter species; 4) palpal femur with a ventral terminal apophysis, instead of a VFG, whereas with a VFG in T. brachialis sp. n.. Female unknown.

Description. Male ( Figs 13–15 ). Total length 2.74–3.17 (n = 6). Holotype: body 3.11 long; carapace 1.32 long, 1.09 wide; abdomen 1.79 long, 1.01 wide. Carapace ( Fig. 13A ) yellow-brown, ovoid in dorsal view, truncate at posterior margin, between fovea and PER, sparsely covered with tiny granulations. CRW 0.75, 0.69 times carapace width. Fovea dark brown, distinct. Eyes ringed with black. AER straight and PER recurved in dorsal view ( Fig. 13C ); AME conspicuously smaller than the other eyes. Eye diameters: AME 0.07, ALE 0.10, PME 0.09, PLE 0.09. Eye interdistances: AME–AME 0.05, AME–ALE 0.03, PME–PME 0.11, PME–PLE 0.09, ALE–PLE 0.09. MOA 0.21 long, anterior width 0.17, posterior width 0.29. PERW 0.55, 0.73 times CRW. Clypeus height 0.07, same with diameter of AME.

Chilum present ( Fig. 13D ). Chelicerae yellow-brown, granulated as the carapace, cheliceral boss pronounced, with three promarginal and two retromarginal teeth. Endites and labium ( Fig. 13B ) light yellow; endites without oblique depression; labium wider than long, without lateral invaginations basally or apical depression. Sternum light yellow, shield-shaped, with sharp precoxal triangles and intercoxal sclerites.

Legs light yellow; femur I brown and more robust than femora II–IV; short, black ventral leg cusps present on tarsi I, metatarsi I–II and tibia I, arranged sparsely in single line ( Figs 13E–H ). Measurements of legs: leg I 3.84 (1.18, 0.52, 0.93, 0.73, 0.48), II 3.27 (0.97, 0.45, 0.79, 0.63, 0.43), III 2.18 (0.63, 0.34, 0.41, 0.50, 0.30), IV 3.44 (1.01, 0.42, 0.85, 0.81, 0.35). Leg formula: 1423. Abdomen long oval, dark yellow-brown, laterally grey; dorsal scutum large, almost covering the whole abdomen ( Fig. 13A ). Venter pale grey, with two narrow lines of sclerotized spots, barely visible ( Fig. 13B ).

Palp as illustrated ( Figs 14–15 ). Femur without ventral groove, but with ventral terminal apophysis. Patella with large subtriangular apophysis in retrolateral view. Tibia with one massive and one smaller apophysis dorsally; massive one long and thick, with two weak nodes, like a bamboo stem, and blunt tip pointed retrolaterally; smaller apophysis thick and short, pointed posteriorly. Tegulum nearly oval; sperm duct discernable through translucent cuticle; subtegulum visible in dorsal view; tegular apophysis absent, with groove on apical part ventrally. Embolus slender, originating from top of tegulum, erect, bifurcated apically. Cymbium tip with bunch of setae dorsally.

Distribution. Known from two localities in the Sichuan and Guizhou Provinces ( Fig. 19 ).

Figures

FIGURE 13. Trachelas gigapophysis sp. n., male, A. habitUs, dorsal view; B. same, ventral view; C. ocUlar area, dorsal view; D. cephalothorax, frontal view; E. left leg I, prolateral view; F. left metatarsUs and tarsUs I, ventral view; G. left metatarsUs and tarsUs II, prolateral view; H. same, ventral view;. Scale bars: 1 mm (A – B); 0.2 mm (C – H).

FIGURE 14. Trachelas gigapophysis sp. n., A. male left palp, prolateral view; B. same, ventral view; C. same, retrolateral view; D. same, dorsal view. Scale bars: 0.2 mm (A – D).

FIGURE 15. Trachelas gigapophysis sp. n., A. male left palp, prolateral view; B. same, ventral view; C. same, retrolateral view; D. same, dorsal view. Scale bars: 0.25 mm (A – D).

FIGURE 19. DistribUtion of new species and T. vulcani Simon, 1896 from SoUthwest China.