Psechrus triangulus Yang, Zhang, Zhu & Song 2003
Creators: name: Bayer, Steffen
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Psechridae
Psechrus
Psechrus triangulus

description: Psechrus triangulus Yang, Zhang, Zhu & Song, 2003
Figs 54a–g, 86b, 89b, 92b
Psechrus triangulus Yang, Zhang, Zhu and Song 2003: 43, figs A–F (Description of ♂ and ♀, illustration of ♂ and ♀). [Holotype ♀ (SB 881) from CHINA: Yunnan Province: Yunlong County, Jiancao, ca. N 26°00', E 99°21', 1700–2500 m; E.B. Yang leg. 30.IV.2002; MHBU; Paratypes: 1 ♂ (SB 882), 5 ♀♀, with same data as for holotype; MHBU, holotype and male paratype examined, female paratypes not available on request, thus not examined].
Revised diagnosis (see also diagnosis for sinensis -group above). Males similar to P. sinensis in having long embolus base (EB) (longer than conductor [C]), possessing numerous tubercles distally (Figs 52b–c, 54b–c). Distinguished by the broad distal part of embolus (E), the two semicircular, platform-like apophyses at EB and the tip of C pointing apically (Fig. 54b). Females similar to P. sinensis in having median septum (MS) with posterior part at least four times broader than anterior part (Figs 53a, 54e). Copulatory ducts (CD) without twist, the bulbous sections of CD about as broad as spermatheca (Figs 53b, 54f). Distinguished by the triangular shape of MS (Fig. 54e), the narrower copulatory ducts and the spermatheca laterally clearly extending beyond CD (Fig. 54f). Additionally, in epigyne the anterior margins of the lateral lobes are visible (Fig. 54e).
Description. Male:
Body and eye measurements. Carapace length 7.4, carapace width 5.4, anterior width of carapace 2.9, opisthosoma length 9.5, opisthosoma width 4.7. Eyes: AME 0.38, ALE 0.40, PME 0.42, PLE 0.42, AME–AME 0.17, AME–ALE 0.08, PME–PME 0.26, PME–PLE 0.36, AME–PME 0.52, ALE–PLE 0.44, clypeus height at AME 0.96, clypeus height at ALE 0.81.
Cheliceral furrow with three promarginal and four retromarginal teeth.
Measurements of palp and legs. Leg formula: 1423. Palp: 10.0 [3.6, 1.7, 1.2, 3.5]; Legs: I 51.5 [13.6, 3.0, 14.3, 13.9, 6.3], II 40.2 [11.0, 3.0, 10.9, 10.7, 4.6], III 27.8 [8.2, 2.2, 6.6, 7.4, 3.4], IV 40.5 [11.4, 2.6, 10.5, 11.3, 4.7].
Spination. Palp: 131, 110(both spines very small), 1101(all spines very small); legs: femur I 516, II 526, III 536 {335}, IV 524; patella I–IV 000; tibia I 3037, II 3036, III 2026 {2036}, IV 2036; metatarsus I– IV 3035.
Palpal femur ventrally modified with rounded bulge (Fig. 54d).
Copulatory organ (see also diagnosis and general description for sinensis -group). Conductor (C) apically distinctly narrower than centrally but its tip rounded (Fig. 54b), not pointed. Embolus (E) strangely folded. Sperm duct with broad V-shaped course (Fig. 54b). Palpal tibia distinctly short (Figs 54a–c).
Female:
Body and eye measurements. Carapace length 7.3, carapace width 4.1, anterior width of carapace 2.2, opisthosoma length 9.9, opisthosoma width 5.8. Eyes: AME 0.38, ALE 0.42, PME 0.43, PLE 0.43, AME–AME 0.17, AME–ALE 0.08, PME–PME 0.24, PME–PLE 0.38, AME–PME 0.62, ALE–PLE 0.47, clypeus height at AME 1.08, clypeus height at ALE 0.94.
Cheliceral furrow with three promarginal and four retromarginal teeth.
Measurements of palp and legs. Leg formula: 1423. Palp: 9.2 [3.1, 1.4, 1.6, 3.1]; Legs: I 40.8 [11.2, 3.3, 11.3, 10.2, 4.8], II 33.0 [9.6, 2.9, 9.0, 7.6, 3.9], III 23.3 [6.9, 2.2, 5.5, 5.8, 2.9], IV 33.2 [9.5, 2.6, 8.8, 8.3, 4.0].
Palpal claw with 15 teeth.
Spination. Palp: 131, 110, 2101{1101}, 1014; legs: femur I 516, II 515, III 535, IV 524; patella I–IV 000; tibia I 3038, II 3036 {3037} III 2034, IV 2035; metatarsus I– IV 3035.
Copulatory organ (see also diagnosis and general description of sinensis -group). Epigynal field with anteriolateral extensions, associated with the long and narrow epigynal muscle sigilla. Slit sense organs outside EF (Fig. 54e). In comparison to P. sinensis spermathecal heads arising further dorsally at spermathecae (Fig. 54f).
Colouration of male and female (see also description for sinensis -group and Psechrus). Median bands on carapace at most slightly serrated. Lateral bands very narrow (at most 0.3 diameter of PME) and at most slightly lobed. Light longitudinal line ventrally on opisthosoma strongly constricted subdistally and quite broad. If measured centrally on opisthosoma, its width is slightly less than or as broad as the width of one half of the cribellum (ca. 0.8–1.0 of one half of the cribellum). Distal part (patch) broader than main section.
Distribution. China (Fig. 96).
description: Published as part of Bayer, Steffen, 2012, The lace-sheet-weavers — a long story (Araneae: Psechridae: Psechrus), pp. 1-170 in Zootaxa 3379 (1) on pages 100-102, DOI: 10.11646/zootaxa.3379.1.1, http://zenodo.org/record/6039832