Nematogmus ligulatus 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 : 117

Nematogmus ligulatus Irfan, Zhang & Peng , sp. n.

(Zäżȃe)

Figures 150–152 , 307 , 313

Types. Holotype ♂, CHINA, Hubei Prov.: Xuanen Co., Zhang Tanhe Township, Mahuping Vill ., 29.97436°N, 109.582645°E, 509 m, 05.V.2016, W. Liu et al. leg. Paratypes: 1♂ 7♀, with same data as for holotype; 1♂ 2♀, Shimen Co., Huping Mountain , Jinban Mountain Vill. , 30.00013°N, 110.05099°E, 440 m, 14.VI.2014, C. Wang et al. leg.; Chongqing: 1♂, Nanchuan Co., Dayou Town , 28.997361°N, 107.33591°E, 1021 m, 13.VIII.2015, X.J. Peng et al. leg .

Etymology. The specific epithet is derived from the Latin adjective “ligulatus ” meaning “in the form of tongue”, referring tongue-like tailpiece in male palp.

Diagnosis. Nematogmus ligulatus sp. n. resembles N. longior in having the similar tailpiece, cymbium with conspicuous outwardly curved apophysis, embolic membrane lamina curved, extending upright in male palp and the epigyne with coiled copulatory ducts ( Figs 150A–D , 151A–C ; Song & Li 2008, figs 3, 4), and can be distinguished by the tibia with one triangular retrolateral tooth in N. ligulatus sp. n. ( Figs 150B, C ; vs. with two teeth). In epigyne, ventral plate scape absent, the lateral walls curved inward, forming a conspicuous hole on each side posteriorly in N. ligulatus sp. n. ( Figs 151A–C ; vs. short scape present, forms lip-like structure); copulatory ducts with three and half spiral coils in N. ligulatus sp. n. ( Fig. 151C ; vs. with two spiral coils); dorsal plate rectangular in N. ligulatus sp. n. ( Fig. 151C ; vs. trapezoidal).

Description. Male (holotype, Figs 152A–C ): Total length: 1.91. Carapace 0.79 long, 0.73 wide, yellow, fovea, cervical and radial grooves distinct; cephalic pits present behind the PLEs; cephalic region slightly elevated. Clypeus 0.22 high. Chelicerae with three promarginal and four retromarginal teeth. Sternum wider than long, dark orange with microsetae. Eyes: AER recurved, PER procurved, slightly wider. Eye sizes and interdistances: AME 0.04, ALE 0.07, PME 0.05, PLE 0.05, AME–AME 0.03, PME–PME 0.05, AME–ALE, 0.05, PME–PLE 0.06, AME–PME 0.06, ALE–ALE 0.31, PLE–PLE 0.32, ALE– PLE contiguous. Length of legs: I 4.56 (1.34, 1.40, 1.13, 0.69), II 4.19 (1.23, 1.31, 1.04, 0.61), III 2.98 (0.90, 0.86, 0.75, 0.47), IV 3.39 (1.04, 0.94, 0.81, 0.50). TmI 0.63, TmIV absent. Tibial spine formula: 1-1-1-1. Opisthosoma 1.29 long, 0.71 wide, oval, pink, dorsally with two pairs of sigillae.

Palp ( Figs 150A–D ): Femur unmodified, as long as both patella and tibia. Patella as long as tibia. Tibia widened distally with one retrolateral triangular tooth, retrolateral tibial apophysis (RTA) rectangular and the prolateral tip extending towards the lateral wall of the cymbium, as well as with one retrolateral and one prolateral trichobothria; cymbium of peculiar shaped, with a conspicuous outwardly curved apophysis; dorsal side of cymbium with a row of minute warts, each bearing a seta; paracymbium (PC) L-shaped, distal arm tip hook-shaped; tegulum (T) mesal to subtegulum, with thumb-shaped ventral apophysis extending towards the patella; protegulum (PT) transparent, ribbonlike, curved; distal suprategular apophysis (DSA) with distal end broad round, slightly grooved, arranged above the base of embolic membrane. Column (C) semicircular with blunt end in ventral view. Tailpiece (TP) of embolic division tongue-shaped with blunt tip; embolic membrane (EM) with long curved lamina extending upright; embolus (E) long, coiled.

Female (one of the paratypes, Figs 152D–F ): Total length: 2.02. Carapace 0.8 long, 0.73 wide, yellow, fovea, cervical and radial grooves distinct; cephalic region slightly elevated. Clypeus 0.17 high. Chelicerae with four promarginal and four retromarginal teeth. Sternum wider than long, dark orange with microsetae. Eyes: AER recurved, PER procurved, slightly wider. Eye sizes and interdistances: AME 0.04, ALE 0.06, PME 0.05, PLE 0.05, AME–AME 0.04, PME–PME 0.06, AME–ALE, 0.05, PME–PLE 0.06, AME–PME 0.05, ALE–ALE 0.31, PLE–PLE 0.32, ALE–PLE contiguous. Length of legs: I 4.56 (1.31, 1.39, 1.16, 0.70), II 4.35 (1.27, 1.33, 1.08, 0.67), III 3.32 (1.01, 0.95, 0.84, 0.52), IV 4.02 (1.20, 1.23, 1, 0.59). TmI 0.64, TmIV absent. Tibial spine formula: 1-1-1-1. Opisthosoma 1.41 long, 1.01 wide, oval, pink, dorsally with two pairs of sigillae.

Epigyne ( Figs 151A–C ): Ventral plate (VP) lateral walls curved inward, with conspicuous holes on each side posteriorly with copulatory openings (CO). Dorsal plate (DP) rectangular, strongly overlapping the ventral plate; copulatory ducts (DP) with spiral coils extending anteriorly. Spermathecae (S) somewhat U-shaped, with short globular arms slightly overlapping with long, oblong arms. Fertilization ducts (FD) short, directed mesally.

Distribution. Known only from the type localities (Chongqing and Hubei Province, Figs 307 , 313 ).

Figures

FIGURE 150. Nematogmus ligulatus sp. n., male holotype. A Palp, dorsal view; B, D Palp, retrolateral view; C Palp, ventral view. Abbreviations: C—column; DSA—distal suprategular apophysis; E—embolus; EM—embolic membrane; PC —paracymbium; PT—protegulum; R—radix; RTA—retrolateral tibial apophysis; SPT—suprategulum; ST—subtegulum; T—tegulum; TP— tailpiece of radix.

FIGURE 151. Nematogmus ligulatus sp. n., female paratype. A, B Epigyne, ventral view; C Vulva, dorsal view. Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermatheca; VP—ventral plate.

FIGURE 152. Nematogmus ligulatus sp. n., male holotype (A–C) and female paratype (D–F). A, D Habitus, dorsal view; B, E Habitus, lateral view; C, F Habitus, ventral view.

FIGURE 307. Distribution of Linyphiidae species in Chongqing: 1. Bathyphantes paracymbialis Tanasevitch, 2014; 2. Diplocephalus circularis sp. n.; 3. Frontinella zhui Li & Song, 1993; 4. Gnathonarium dentatum (Wider, 1834); 5. Gongylidioides acuminatus sp. n.; 6. Gongylidioides ensis sp. n.; 7. Gongylidium uncatum sp. n.; 8. Himalaphantes azumiensis (Oi, 1979); 9. Hylyphantes graminicola (Sundevall, 1830); 10. Indophantes wushanensis Irfan, Wang & Zhang, 2023; 11. Lepthyphantes frondeus sp. n.; 12. Wulinggone qizimeiensis sp. n.; 13. Nematogmus ligulatus sp. n.; 14. Nematogmus sanguinolentus (Walckenaer, 1841); 15. Nippononeta alpina (Li & Zhu, 1993); 16. Nippononeta coreana (Paik, 1991); 17. Oia yinae sp. n.; 18. Oilinyphia xinqiaoensis sp. n.; 19. Oilinyphioides triangularis sp. n.; 20. Prosoponoides sinensis (Chen, 1991); 21. Scotinotylus guizhouensis sp. n.; 22. Sinolinyphia henanensis (Hu, Wang & Wang, 1991); 23. Syedra yuelushanensis sp. n.; 24. Ummeliata feminea (Bösenberg & Strand, 1906); 25. Ummeliata insecticeps (Bösenberg & Strand, 1906); 26. Walckenaeria sinuosa sp. n.; 27. Wuliphantes tongluensis (Chen & Song, 1988).

FIGURE 313. Distribution of Linyphiidae species in Hubei Prov.: 19. Lepthyphantes ellipticus sp. n.; 20. Lepthyphantes frondeus sp. n.; 21. Linyphia songziyuanensis sp. n.; 22. Lenis longiabdominis sp. n.; 23. Wulinggone qizimeiensis sp. n.; 24. Nematogmus ligulatus sp. n.; 25. Nematogmus sanguinolentus (Walckenaer, 1841); 26. Nippononeta coreana (Paik, 1991); 27. Oedothorax collinus Ma & Zhu, 1991; 28. Paikiniana lurida (Seo, 1991); 29. Parameioneta bilobata Li & Zhu, 1993; 30. Wulingnus furcatus sp. n.; 31. Wulingnus inversus sp. n.; 32. Platyspira tanasevitchi Song & Li, 2009; 33. Prosoponoides sinensis (Chen, 1991); 34. Ryojius lianghekouensis sp. n.