Nematogmus ligulatus Irfan, Zhang & Peng, sp. n.
Creators: name: Irfan, Muhammad
name: Zhou, Gu-Chun
name: Peng, Xian-Jin
name: Zhang, Zhi-Sheng
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Nematogmus
Nematogmus ligulatus

description: 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).
description: Published as part of Irfan, Muhammad, Zhou, Gu-Chun, Peng, Xian-Jin & Zhang, Zhi-Sheng, 2025, Survey of Linyphiidae spiders (Arachnida: Araneae) from some Oriental Regions of China, pp. 1-248 in Megataxa 15 (1) on page 117, DOI: 10.11646/megataxa.15.1.1, http://zenodo.org/record/14985176