Oilinyphia daxuensis Irfan, Zhang & Peng

Irfan, Muhammad, Zhou, Gu-Chun, Peng, Xian-Jin & Zhang, Zhi-Sheng, 2025, Survey of Linyphiidae spiders (Arachnida: Araneae) from some Oriental Regions of China, Megataxa 15 (1), pp. 1-248 : 137-138

Oilinyphia daxuensis Irfan, Zhang & Peng , sp. n.

(大ª奥me)

Figures 177–179 , 317

Types. Holotype ♂ ( HNU–XZ–0011 ), CHINA, Xizang: Changdu City, Mangkang Co., Qufuka Township , Daxu Vill. , 29.06600°N, 97.07995°E, 3412 m, 25.V.2017, Y. Zhen & Q. Cai leg. Paratypes: 1♀, Mangkang Co., Rumei Town , 29.82621°N, 98.39941°E, 3980 m, 30.IV.2017, Q. Cai leg. ( HNU–XZ–0008 ); 1♀, Mangkang Co., Xuzhong Township, Haza Vill. , Jumei Group , 29.19672°N, 98.79543°E, 3208 m, 23.IV.2017, Q. Cai leg. ( HNU–XZ– 0003 ).

Etymology. This specific name derived from the type locality; adjective.

Diagnosis. Oilinyphia daxuensis sp. n. resembles O. hengji in having the similar somatic morphology of both sexes, U-shaped paracymbium in male palp and the ventral plate wide, extended mesally with a truncated end in epigyne ( Figs 177A–D , 178A–C ; Zhao & Li 2014, figs 69–72), but can be distinguished by the lamella longer than wide, proximal end sword-shaped with pointed end in O. daxuensis sp. n. ( Figs 177A–D ; vs. sinuous with three apophyses); embolus sickle-shaped in dorsal view, distal tip hook-shaped in retrolateral view in O. daxuensis sp. n. ( Fig. 177C ; vs. sclerotized, slightly curved with blunt end); distal suprategular apophysis curved, distal end with knob in O. daxuensis sp. n. ( Figs 177B, C ; vs. thorn-shaped). Female can be differentiated by the median extension of the spermathecae oval in O. daxuensis sp. n. ( Figs 178B, C ; vs. globular); copulatory duct almost equal the length of posterior margin of ventral plate in O. daxuensis sp. n. ( Figs 178B, C ; vs. almost half the length of posterior margin of ventral plate).

Description. Male (holotype, Figs 179A, B ): Total length: 1.33. Carapace 0.57 long, 0.45 wide, dark brown, round posteriorly, with long thick setae. Clypeus 0.21 high. Chelicerae with one promarginal and two retromarginal teeth. Sternum shield-like, dark brown with microsetae. Eyes: AER recurved, PER straight. Eye sizes and interdistances: AME 0.06, ALE 0.07, PME 0.05, PLE 0.06, AME–AME 0.01, PME–PME 0.05, AME–ALE, 0.03, PME–PLE 0.03, AME–PME 0.06, ALE–ALE 0.28, PLE–PLE 0.28, ALE–PLE contiguous. Length of legs: I 1. 81 (0.44, 0.57, 0.51, 0.29), II 1. 73 (0.39, 0.55, 0.47, 0.32), III 1.41 (0.37, 0.42, 0.35, 0.27), IV 1.83 (049, 0.56, 0.45, 0.33). Legs with annuli; formula IV-I-II-III. TmI 0.36 and TmIV 0.26. Tibial spine formula: 2-2-2-2. Opisthosoma 0.82 long, 0.57 wide, oval, blackish brown, with attenuated posterior tip, adorned with ridges and papillae.

Palp ( Figs 177A–D , 178D ): Femur unmodified, almost longer than patella, tibia and cymbium. Patella as long as tibia, dorsally with long spine. Tibia conic, with one reterolateral trichobothria; cymbium unmodified, small, round in dorsal view, with spines; paracymbium (PC) U-shaped; protegulum (PT) reduced; distal suprategular apophysis (DSA) curved, distal end with knob. Median membrane (MM) slender, short with attenuated tip. Lamella (L) longer than wide, proximal end gradually narrow towards tip with pointed end, distal end relatively broad with teeth in ventral view. Embolus (E) sickle-shaped in dorsal view, distal tip hook-shaped in retrolateral view.

Female (one of the paratypes, Figs 179C, D ): Total length: 1.71. Carapace 0.61 long, 0.48 wide, dark brown, round posteriorly, with long thick spines. Clypeus 0.12 high. Chelicerae with one promarginal and two retromarginal teeth. Sternum shield-like, dark brown with microsetae. Eyes: AER recurved, PER straight. Eye sizes and interdistances: AME 0.05, ALE 0.06, PME 0.06, PLE 0.05, AME–AME 0.02, PME–PME 0.04, AME–ALE, 0.02, PME–PLE 0.02, AME–PME 0.05, ALE–ALE 0.26, PLE–PLE 0.27, ALE–PLE contiguous. Length of legs: I 1. 98 (0.56, 0.59, 0.51, 0.32), II 1. 88 (0.55, 0.56, 0.43, 0.34), III 1.56 (0.45, 0.42, 0.38, 0.31), IV 2.02 (0.58, 0.62, 0.46, 0.36). Legs with annuli; formula IV-I-II-III. TmI 0.32 and TmIV 0.23. Tibial spine formula: 2-2-2-2. Opisthosoma 1.23 long, 0.79 wide, same coloration and pattern as in male.

Epigyne ( Figs 178A–C ): Ventral plate (VP) wide, extended mesally with a truncated end; copulatory ducts (CD) short, simple, directly enters the spermathecae. Spermathecae (S) present at the apex, spaced by less than their diameters. Fertilization ducts (FD) short, extending upward.

Distribution. Known only from type localities (Xizang Province, Fig. 317 ).

Figures

FIGURE 177. Oilinyphia daxuensis sp. n., male holotype. A Palp, prolateral view; B Palp, retrolateral view; C Palp, dorsal view; D Palp, ventral view. Abbreviations: DSA—distal suprategular apophysis; E—embolus; L—lamella; MM—median membrane; PC—paracymbium; ST—subtegulum; T—tegulum.

FIGURE 178. Oilinyphia daxuensis sp. n., female paratype (A–C), male holotype (D). A, B Epigyne, ventral view; C Vulva, dorsal view; D Palp, patella and tibia retrolateral view.Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermatheca; VP—ventral plate.

FIGURE 179. Oilinyphia daxuensis sp. n., male holotype (A, B) and female paratype (C, D). A, C Habitus, dorsal view; B, D Habitus, ventral view.

FIGURE 317. Distribution of Linyphiidae species in Xizang: 1. Microneta circumacta sp. n.; 2. Oilinyphia daxuensis sp. n.; 3. Walckenaeria furcillata (Menge, 1869).