Bifidocoelotes obscurus Zhou, Yuen & Zhang, 2017, sp. nov.
Creators: name: Zhou, Yan-Chen
name: Yuen, Yan Ling
name: Zhang, Zhi-Sheng
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Amaurobiidae
Bifidocoelotes
Bifidocoelotes obscurus

description: Bifidocoelotes obscurus sp. nov. (ŔǠDZĦ)
Figures 1 A–E, 2A–G
Type material. Holotype male, China, Hong Kong, Tai Po Kau Forest Stream, 22°25′24′′N, 114°10′48′′E, 9 January 2014, Y.L. Yuen leg. Paratypes (9 males and 10 females): 3 males and 1 female, with same data as holotype; 2 males and 2 females, Hong Kong, Lead Mine Pass Stream, 22°23′51′′N, 114°09′05′′E, 5 December 2013, Y.L. Yuen leg.; 1 female, Hong Kong, Lead Mine Pass Stream. 22°23′51′′N, 114°09′05′′E, 18 December 2013, Y.L. Yuen leg.; 1 male and 2 females, Hong Kong, Lead Mine Pass Stream. 22°23′51′′N, 114°09′05′′E, 10 January 2014, Y.L. Yuen leg.; 1 male and 3 females, Hong Kong, Tai Po Kau Forest Stream, 22°25′24′′N, 114°10′48′′E, 12 December 2013, Y.L. Yuen leg.; 1 female, Hong Kong, Tai Po Kau Forest Stream, 22°25′24′′N, 114°10′48′′E, 24 January 2014, Y.L. Yuen leg.; 2 males, Hong Kong, 2014, Y.L. Yuen leg.
Etymology. The specific epithet comes from the Latin word obscurus, meaning “dark”, referring to the dark habitus; adjective.
Diagnosis. The new species can be distinguished from the type species, B. bifidus (Wang 2002: 38, figs 86–91) by the large and strongly bifid conductor and relatively large median apophysis of the male pedipalp (Figs 1 C–E, 2E–G) (conductor shorter and less bifid, with shorter branches and median apophysis smaller in B. bifidus (Wang 2002: figs 88–89)), the long and shallowly bifurcated epigynal tooth, the strongly coiled and well-sclerotized copulatory ducts and the ball-like spermathecae of the female epigyne (Figs 1 A–B, 2C–D) (tooth long and deeply bifurcated, copulatory ducts elongate and weakly sclerotized and spermathecae elongate in B. bifidus (Wang 2002: figs 86–87)). The new species differs from B. primus by the tiny pointed lateral tibial apophysis and relatively straight conductor of the male pedipalp (Figs 1 D–E, 2F–G) (lateral tibial apophysis rounded and conductor spiraled in B. primus (Figs 3 D–E, 4F–G)) and the shallowly bifurcated tooth and small copulatory openings of the epigyne (Figs 1 A, 2C) (tooth very deeply bifurcated and copulatory openings elongate in B. primus (Figs 3 A, 4C)).
Description. Male. Total length 6.83–7.37. Holotype (Fig. 2 A) total length 6.83. Prosoma 3.46 long, 2.25 wide; opisthosoma 3.20 long, 2.26 wide. Eye region and dorsum of prosoma dark. Cervical groove and radial furrows distinct. Eye sizes and interdistances: AME 0.09, ALE 0.15, PME 0.19, PLE 0.18; AME–AME 0.06, AME–ALE 0.03, PME–PME 0.08, PME–PLE 0.11, ALE–PLE 0.05. MOA 0.42 long, front width 0.28, back width 0.42. Clypeus height 0.16. Chelicerae robust, brown, with three promarginal and two retromarginal teeth. Gnathocoxae yellow brown, longer than wide. Labium yellow brown, longer than wide. Sternum brown and scutiform, with sparse brown hairs. Legs yellow brown, with black ring-like stripe in femora, patella and tibia. Leg measurements: I 11.02 (3.02, 3.48, 2.58, 1.94); II 9.02 (2.45, 2.76, 2.22, 1.59); III 8.20 (2.22, 2.49, 2.30, 1.19); IV 11.76 (3.04, 3.73, 3.38, 1.61). Leg formula: 4123. Opisthosoma oval. Dorsum yellowish brown, with dark markings and some light chevron-like markings. Venter yellow brown, with some dark markings.
Male pedipalp (Figs 1 C–E, 2E–G). Patellar apophysis strong, finger-like in retrolateral view. RTA wide, with a somewhat rounded distal end, extending beyond distal end of tibia. Lateral tibial apophysis small and pointed. Embolus very long and slender, proximally originated. Conductor strong, relatively straight and deeply bifurcated with distal arm shorter and slightly curved distally and proximal arm longer. Median apophysis relatively large and spoon-like.
Female. Measurements from a single paratype (Fig. 2 B). Total length 6.65. Prosoma 3.27 long, 2.15 wide; opisthosoma 3.58 long, 2.47 wide. Eye sizes and interdistances: AME 0.09, ALE 0.16, PME 0.16, PLE 0.20; AME–AME 0.08, AME–ALE 0.04, PME–PME 0.07, PME–PLE 0.08, ALE–PLE 0.06. MOA 0.38 long, front width 0.25, back width 0.41. Clypeus height 0.16. Leg measurements: I 8.46 (2.34, 2.78, 2.00, 1.34); II 7.26 (2.06, 2.32, 1.72, 1.16); III 6.59 (1.84, 2.12, 1.66, 0.97); IV 9.41 (2.59, 3.12, 2.48, 1.21). Leg formula: 4123. Dorsum yellowish brown, with dark markings and some light chevron-like markings. Venter yellow brown, with some dark markings.
Epigyne (Figs 1 A–B, 2C–D) with a shallowly bifurcated epigynal tooth (slightly variable among individuals). Copulatory openings small, located on the lateral side of epigynal tooth. Copulatory ducts and spermathecae difficult to differentiate from each other, strong convoluted and sclerotized. Spermathecal heads located anteriorly. Bases of spermathecae well separated. Fertilization ducts originating ventrally on spermathecae.
Distribution. Known only from Hong Kong (China).
description: Published as part of Zhou, Yan-Chen, Yuen, Yan Ling & Zhang, Zhi-Sheng, 2017, A new Bifidocoelotes species, with the description of the male of B. primus from Hong Kong, China (Agelenidae: Coelotinae), pp. 429-436 in Zootaxa 4232 (3) on pages 430-432, DOI: 10.11646/zootaxa.4232.3.11, http://zenodo.org/record/312051