Trachelas gaoligongensis, 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 : 42-44

Trachelas gaoligongensis sp. n.

Figs 16 , 18A–B

Type material. Holotype: ♀, CHINA: Yunnan Province: Baoshan City, Longling County, Longxin Township , Xiaoheishan Nature Reserve (24°31.156′N, 98°50.504′E), 2183m a.s.l., 16 February 2011, leg. Luyu Wang . Paratypes: 1♀, same data as holotype ; 1♀, Yunnan Province: Baoshan City, Tengchong County, Wuhe Township , Xiaodifang Village (24°53.112′N, 98°45.346′E), 2210m a.s.l., 27 February 2011, leg. Luyu Wang. All specimens are deposited in MHBU .

Etymology. The species name “ gaoligongensis ” refers to the Gaoligong mountain range, where the type locality is found; adjective.

Diagnosis. The new species can be easily distinguished from all the other Old World Trachelas species by: 1) atrium horseshoe-shaped, with distinct sclerotized lateral and anterior margins; 2) copulatory openings situated posteriorly. Male unknown.

Description. Female ( Figs 16 , 18A–B ). Total length 4.07–4.85 (n = 3). Holotype: body 4.85 long; carapace 1.80 long, 1.61 wide; abdomen 3.05 long, 2.27 wide. Carapace ( Fig. 16A ) dark brown, ovoid in dorsal view, highest at fovea, without granulations. CRW 0.94, 0.58 times carapace width. Fovea black, distinct. Eyes ringed with black. AER and PER recurved in dorsal view ( Fig. 16C ). Eye diameters: AME 0.14, ALE 0.13, PME 0.13, PLE 0.14. Eye interdistances: AME–AME 0.08, AME–ALE 0.01, PME–PME 0.13, PME–PLE 0.09, ALE–PLE 0.08. MOA 0.29 long, anterior width 0.33, posterior width 0.39. PERW 0.70, 0.74 times CRW. Clypeus height 0.12, narrower than diameter of AME.

Chilum present ( Fig. 16E ). Chelicerae dark brown, cheliceral boss pronounced, with three promarginal and two retromarginal teeth. Endites and labium ( Fig. 16B ) yellow-brown; endites without oblique depression; labium wider than long. Sternum yellow-brown, shield-shaped, with sharp precoxal triangles and blunt intercoxal sclerites.

Legs light yellowish-brown, with black rings ( Figs 16A–B ); leg cusps absent. Measurements of legs: leg I 5.60 (1.71, 0.76, 1.28, 1.06, 0.79), II 5.48 (1.63, 0.73, 1.27, 1.06, 0.79), III 4.32 (1.23, 0.61, 0.89, 1.05, 0.54), IV 6.13 (1.78, 0.67, 1.43, 1.52, 0.73). Leg formula: 4123. Abdomen oval, pale grey, dorsally with several dark grey chevrons; dorsal scutum absent ( Fig. 16A ). Venter pale grey, with four narrow lines of sclerotized spots, barely visible; laterally with dark grey reticulate pattern ( Fig. 16B ).

Epigyne ( Figs 16F , 18A ): poorly sclerotized, atrium horseshoe-shaped, with distinct lateral margin and extended sclerotized anterior margin; hood absent; copulatory openings small, pore-like, situated posteriorly, at base of atrial lateral margin. Vulva ( Figs 16G , 18B ): copulatory ducts short, thick, sharply curved anteriorly; ST2 large, elongate-oval, connecting with inflated duct; connecting ducts slender, anterior part curved along the atrium and posterior part straight longitudinally before entering ST1; ST1 oval, connected to weakly sclerotized FD.

Distribution. Known from two localities in the Yunnan Province ( Fig. 19 ).

Figures

FIGURE 16. Trachelas gaoligongensis sp. n., female, A. habitUs, dorsal view; B. same, ventral view; C. ocUlar area, dorsal view; D. cephalothorax, frontal view; E. same, frontal-ventral view; F. epigyne, ventral view; G. vUlva, dorsal view. Scale bars: 1 mm (A – B); 0.2 mm (C – G).

FIGURE 18. A – B, Trachelas gaoligongensis sp. n., C – D, Trachelas shilinensis sp. n., A. epigyne, ventral view; B. vUlva, dorsal view; C. epigyne, ventral view; D. vUlva, dorsal view. Scale bars: 0.25 mm (A – D).

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