Trachelas bomiensis Jin & Mi 2024, sp. nov.
Creators: name: Liu, Kaizhen
name: Liu, Jiannan
name: Zhang, Feng
name: Li, Liangtao
name: Mi, Xiaoqi
name: Jin, Chi
Publisher: name: Zenodo
Year: 2024
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Trachelidae
Trachelas
Trachelas bomiensis

description: Trachelas bomiensis Jin & Mi, sp. nov. (波ĸDzn)
Figs 1–3
Type material. Holotype: ♂, CHINA: Xizang Autonomous Region: Nyingchi City, Bomi County, Gu Township, Qiaona Village (30°2.00′N, 95°14.18′E), 2453 m a.s.l., 22 August 2023, leg. Xiaoqi Mi, Nonghao Yao and Shikai Li. Paratype: 1♀, same data as holotype.
Etymology. The species name is derived from the type locality; adjective.
Diagnosis. Among the Old World Trachelas species, the new species resembles T. brachialis Jin, Yin & Zhang, 2017 in having a thick, large embolus and the long and coiled connecting ducts, but can be recognized by: 1) the darker body color and absence of chevrons on the abdominal dorsum (vs lighter color and indistinct chevrons on abdomen, cf. Figs 1A, C with figs 10A, E in Jin et al. 2017); 2) the apex of the embolus is not branched and is spiraled in the shape of a drill bit (vs branched and not spiraled, cf. Figs 2A, B with figs 11B, D in Jin et al. 2017); 3) the goose-head-shaped patellar apophysis and undeveloped tibial apophysis (vs subrectangular and well developed, cf. Fig. 2B with fig. 11B in Jin et al. 2017); 4) the epigynal plate without a hood (vs with a small upward hood, cf. Fig. 3A with fig. 11E in Jin et al. 2017); and 5) the secondary spermathecae are far apart from each other and the copulatory ducts are short and thick (vs the secondary spermathecae very close to each other and the copulatory ducts curved and inflated, cf. Fig. 3B with fig. 11F in Jin et al. 2017).
Description. Male (Figs 1A–B, 2, 3D–G). Holotype: body 3.99 long; carapace 1.88 long, 1.71 wide; abdomen 2.11 long, 1.46 wide. Carapace (Fig. 1A) ovoid, dark brown, densely covered with tiny granulations, thoracic region with obvious black radial striae. CRW 1.03, 0.60 times carapace width. Fovea black, short. AER and PER recurved in dorsal view. Eye diameters: AME 0.13, ALE 0.12, PME 0.12, PLE 0.12. Eye interdistances: AME–AME 0.07, AME–ALE 0.02, PME–PME 0.13, PME–PLE 0.11, ALE–PLE 0.08. MOA 0.33 long, anterior width 0.30, posterior width 0.37. PERW 0.73, 0.71 times CRW. Clypeus height 0.11, narrower than diameter of AME. Chilum triangular, sclerotized and brown. Chelicerae dark brown, granulated as carapace, with pronounced cheliceral boss, with three promarginal and two retromarginal teeth. Endites brown, labium dark brown (Fig. 1B); labium longer than wide. Sternum brown, shield-shaped, with sharp precoxal triangles; intercoxal sclerites distinctly present between coxae I and II, II and III, and III and IV. Legs light yellow (Fig. 3D–G); short, black ventral leg cusps present on tarsi and metatarsi I–II, arranged in two lines on leg I (Fig. 3F) and sparse, almost only one prolateral line on leg II (Fig. 3G); femora I and II with tuberculate setal bases on surface, more obvious on femur I (Figs 3D, E). Measurements of legs: leg I 5.98 (1.90, 0.74, 1.56, 1.14, 0.64), II 5.72 (1.76, 0.68, 1.41, 1.18, 0.69), III 4.09 (1.18, 0.51, 0.86, 1.09, 0.45), IV 5.51 (1.59, 0.59, 1.26, 1.51, 0.56). Leg formula: 1243. Abdomen oval, light yellowish-brown, without chevrons; lateral sides with black pleats; dorsal scutum present, covering almost entire abdominal dorsum (Fig. 1A). Venter pale grey (Fig. 1B).
Palp as in Fig. 2. Femur with small, shallow ventral terminal groove, with setal bases noticeably tuberculate on ventral surface (Figs 2B, D). Patella with large goose-head-shaped apophysis in retrolateral view, almost as long as patella (Fig. 2B). Tibia with ear-like retrolateral apophysis, its proximal margin with short finger-like process pointing dorsally (Fig. 2C). Tegulum oval, sperm duct S-shaped, clearly visible through translucent cuticle (Fig. 2A); tegular apophysis short, apically inserted, pointed retrolaterally. Embolus well developed, extremely thick, originating from small membranous area distally on prolateral side of tegulum (Fig. 2D), extending retrolaterally along tegular tip, then extending distally after a single coiling, spiraling twice to form drill bit-like apex (Figs 2A, B). Cymbium long, more than twice length of tegulum, about same width as bulb.
Female (Figs 1C–D, 3A–B). Paratype: body 3.60 long; carapace 1.89 long, 1.71 wide; abdomen 2.13 long, 1.51 wide. CRW 1.02, 0.60 times of carapace width. Eye diameters: AME 0.12, ALE 0.13, PME 0.12, PLE 0.12. Eye interdistances: AME – AME 0.09, AME – ALE 0.02, PME – PME 0.14, PME – PLE 0.10, ALE – PLE 0.09. MOA 0.31 long, anterior width 0.29, posterior width 0.36. PERW 0.67, 0.66 times of CRW. Clypeus height 0.13, slightly wider than diameter of AME. Leg measurements: I 5.69 (1.94, 0.74, 1.35, 1.01, 0.65); II 5.43 (1.65, 0.68, 1.35, 1.08, 0.67); III 4.07 (1.19, 0.54, 0.87, 1.00, 0.47); IV 5.62 (1.64, 0.64, 1.40, 1.45, 0.49). Leg formula: 1423. Carapace, chelicerae and chilum blackish-brown; endites and sternum light dark brown. Sternum with precoxal triangles; intercoxal sclerites weakly present between coxae I and II, II and III, and III and IV. Legs without cusps.Abdomen dorsum and venter mottled dark grey, dorsal scutum absent. Other characters as in male.
Epigyne (Fig. 3A): poorly sclerotized, anteriorly with pair of large oval funnel-shaped depressions having sclerotized arcuate posterior margins; copulatory openings small, situated medially, located at bottom of epigynal depressions, more than twice primary spermatheca’s diameter. Vulva (Figs 3B, C): copulatory ducts very short, with thick walls, extending posteriorly, then bending laterally to connect to secondary spermathecae; secondary spermathecae small and oval, surface with glandular pores; connecting ducts thin and long, coiling around inner wall of epigynal depressions for one and a half times before entering primary spermathecae; primary spermathecae spherical, located posteriorly, less than half a diameter apart from each other; fertilization ducts short.
Distribution. Known only from the type locality (Fig. 4).
description: Published as part of Liu, Kaizhen, Liu, Jiannan, Zhang, Feng, Li, Liangtao, Mi, Xiaoqi & Jin, Chi, 2024, An update on the distribution of the genus Trachelas L. Koch, 1872 (Araneae, Trachelidae) in China, with description of a new species, pp. 567-576 in Zootaxa 5453 (4) on pages 571-574, DOI: 10.11646/zootaxa.5453.4.7, http://zenodo.org/record/11239830