Yunguirius xiannushanensis Wei & Liu, 2024

Wei, Mian, Liu, Jie & Wang, Kai, 2024, Four new species of the genus Yunguirius (Araneae, Agelenidae) from China, ZooKeys 1211, pp. 1-15 : 1-15

Yunguirius xiannushanensis Wei & Liu sp. nov.

Figs 8 , 9 , 10 , 11

Type material.

Holotype ♀ ( HBU-WM-24-006 ): China: Chongqing City, Wulong District, Xiannu Mountain , 29.4508 ° N, 107.7280 ° E, elevation: 1951 m, 15. IX. 2021, T. X. Gu leg.

Etymology.

The new species is named after the type locality, Xiannu Mountain; an adjective.

Diagnosis.

The females of Yunguirius xiannushanensis sp. nov. resemble those of Y. ornatus in 1) the atrium is relatively small, less than 1 / 3 the width of the epigyne, with a reduced anterior margin (Fig. 8 A ; fig. 3 A in Li et al. 2023); 2) the connection of the copulatory duct and the spermatheca presents dorsally (Fig. 8 B ; fig. 3 B in Li et al. 2023). While in other Yunguirius species, the atrium exceeding 1 / 3 the width of the epigyne, with the anterior margin complete ( Y. duoge and Y. parvus sp. nov., fig. 2 A; fig. 2 A in Li et al. 2023) or incomplete ( Y. subterebratus , Y. terebratus , Y. trigonus sp. nov., Y. wangqiqiae sp. nov. and Y. xiangding , figs 1 A, 4 A, 6 A; fig. 245 A in Zhu et al. 2017; fig. 4 A in Li et al. 2023), and the connection of the copulatory duct and the spermatheca presents ventrally (Figs 1 B , 2 B , 4 B , 6 B ; fig. 245 B in Zhu et al. 2017; figs 2 B, 4 B in Li et al. 2023). Y. xiannushanensis sp. nov. can be distinguished from Y. ornatus by the following characteristics: 1) the atrium is pentagonal (Fig. 8 A ), versus being trapezoidal in Y. ornatus (Fig. 3 A in Li et al. 2023); 2) the posterior epigynal sclerite is reduced and thin, roughly a quarter of the width of the atrium (Fig. 8 A ), versus being more substantial and about equal to the width of atrium in Y. ornatus (Fig. 3 A in Li et al. 2023); 3) the copulatory ducts are folded, and with distinct secondary layer (Fig. 8 B ), versus being monolayered in Y. ornatus (Fig. 3 B in Li et al. 2023); 4) the spermathecal bases are large, twice as wide as the stalks, the spermathecal stalks have conch-shaped distal tips, and the spermathecal heads are membranous and only the distal tips are visible (Fig. 8 B ); in contrast, in Y. ornatus , the spermathecal bases are relatively small, slightly wider than the stalks, the distal tips of the stalks are normal, and the spermathecal heads are long and sclerotized (Fig. 3 B in Li et al. 2023).

Description.

Female (holotype) (Fig. 9 ). Carapace reddish brown. Cervical and radial groove distinct. Cephalic region moderately raised and wide, lateral margin with distinct furrows. Chelicerae with 3 promarginal teeth and 2 retromarginal teeth, condyle red. Sternum longer than wide. Abdomen pale yellow, with 5 chevron-shaped patterns, covered by hairs. Legs red. Total length 13.20. Carapace 6.40 long, 4.25 wide, cephalic region 3.70 wide. Abdomen 7.14 long, 4.36 wide. Eye size and interdistance: AME 0.19, ALE 0.25, PME 0.25, PLE 0.28; AME – AME 0.12, AME – ALE 0.18, AME – PME 0.10, ALE – PLE 0.05, PME – PME 0.13, PME – PLE 0.34. Leg measurements: Leg I 17.18 (2.26, 0.75, 4.27, 1.91, 3.57, 3.20, 1.69), leg II 15.25 (1.94, 0.74, 3.79, 1.70, 3.02, 2.79, 1.67), leg III 12.68 (1.64, 0.79, 3.15, 1.45, 2.10, 2.39, 1.40), leg IV 17.77 (1.94, 0.95, 4.40, 1.88, 3.57, 3.49, 1.70). Epigyne (Fig. 8 ). Epigynal teeth absent. Atrium relatively small, pentagonal, anterior margin reduced. Epigynal sclerite small, opalescent. Hoods weak, vertically oriented, situated laterally. Fold distinct, triangular. Copulatory ducts broad, laterally originated, folded into 2 layers, and connected with spermathecae ventrally; blind sacs broad and short. Spermathecal base bean-shaped and twice wider than width of spermathecal stalk; spermathecal stalk long, with distal tip conch-shaped; spermathecal head reduced, only remaining a membranous tip on the distal tip of blind sac. Fertilization ducts posteriorly situated.

Male. Unknown.

Distribution.

China (Chongqing).

Notes.

Our fieldwork indicates that these new Yunguirius species inhabit tube nests with round openings dug into soil, moss, or rotten wood of high humidity, rather than constructing funnel webs beneath rocks or crevices like some other common agelenid spiders. A further study may be required to determine the origins of the burrowing behavior of these spiders.

Figures

Figure 1. Epigyne and vulva of Yunguirius terebratus A epigyne, ventral view B vulva, dorsal view. Abbreviations: A = atrium; BS = blind sac; CD = copulatory duct; CO = copulatory opening; F = fold; FD = fertilization duct; H = hood; MP = mating plug; PES = posterior epigynal sclerite; SB = spermathecal base; SH = spermathecal head; SL = the secondary layer of copulatory duct; SS = spermathecal stalk. The white dashed line in A represents the margin of atrium and in B represents the spermathecal head. The black outline B shows the blind sac of the copulatory duct. The red dashed line and arrow in B indicate the opening of copulatory duct. The blue area indicates the copulatory duct, and the yellow area indicates the secondary layer of the copulatory duct. Scale bar: 0.50 mm.

Figure 2. Epigyne of Yunguirius parvus sp. nov. A epigyne, ventral view B vulva, dorsal view. Abbreviations: A = atrium; BS = blind sac; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct; H = hood; PES = posterior epigynal sclerite; SB = spermathecal base; SH = spermathecal head; SS = spermathecal stalk. The white dashed line B indicates the spermathecal head, the white outline B indicates the fertilization duct. Scale bar: 0.50 mm.

Figure 3. Characters of the female of Yunguirius parvus sp. nov. A habitus, dorsal view B habitus, prolateral view C eye area, frontal view D eye area, dorsal view E cephalic rigion, lateral view. Scale bars: 2.00 mm (A, B); 0.50 mm (C, D); 0.25 mm (E).

Figure 4. Epigyne of Yunguirius trigonus sp. nov. A epigyne, ventral view B vulva, dorsal view. Scale bars: 1.00 mm. Abbreviations: A = atrium; BS = blind sac; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct; H = hood; PES = posterior epigynal sclerite; SB = spermathecal base; SH = spermathecal head; SS = spermathecal stalk. The white dashed line B indicates the spermathecal head, the white outline B indicates the fertilization duct. Scale bar: 0.50 mm.

Figure 6. Epigyne of Yunguirius wangqiqiae sp. nov. A epigyne, ventral view B vulva, dorsal view. Abbreviations: A = atrium; BS = blind sac; CD = copulatory duct; CO = copulatory opening; FD = fertilization duct; H = hood; PES = posterior epigynal sclerite; SB = spermathecal base; SH = spermathecal head; SL = the secondary layer of copulatory duct; SS = spermathecal stalk. Scale bar: 0.50 mm.

Figure 8. Epigyne of Yunguirius xiannushanensis sp. nov. A epigyne, ventral view B vulva, dorsal view C vulva, apical view. Abbreviations: A = atrium; BS = blind sac; CD = copulatory duct; CO = copulatory opening; F = fold; FD = fertilization duct; H = hood; PES = posterior epigynal sclerite; SB = spermathecal base; SH = spermathecal head; SL = the secondary layer of copulatory duct; SS = spermathecal stalk. Scale bars: 0.50 mm.

Figure 9. Characters of the female of Yunguirius xiannushanensis sp. nov. A habitus, dorsal view B habitus, prolateral view C eye area, frontal view D eye area, dorsal view E cephalic region, lateral view. Scale bars: 2.00 mm (A, B); 0.50 mm (C, D); 0.25 mm (E).

Figure 10. Distributions of the species of Yunguirius. 1 Y. duoge 2 Y. ornatus 3 Y. parvus sp. nov. 4 Y. subterebratus 5 Y. terebratus 6 Y. trigonus sp. nov. 7 Y. wangqiqiae sp. nov. 8 Y. xiangding 9 Y. xiannushanensis sp. nov.

Figure 11. Photos of the nest and the living female of Yunguirius xiannushanensis sp. nov. A opening of the tube nest B living female.