Denisiphantes arcuatus, Zhou & Irfan & Peng, 2021

Zhou, Guchun, Irfan, Muhammad & Peng, Xianjin, 2021, A new species of Denisiphantes Tu, Li & Rollard, 2005 (Araneae, Linyphiidae) from Yunnan, China, ZooKeys 1023, pp. 1-12 : 1

Denisiphantes arcuatus sp. nov. Figures 1 , 2 , 3 , 4

Material examined.

Holotype: male, China, Yunnan Province, Nujiang Prefecture, Sanjiang Township , Lushui County, Nu Jiang , 25.72964°N, 98.87180°E, alt. 790 m, 26.VI.2000, leg. D. H. Kavanaugh, Charles Griswold & Heng-mei Yan (HNU-00-Lan-1) . Paratypes: 2 females, collected together with the holotype (HNU-00-Lan-2~3).

Diagnosis.

This new species resembles Denisiphantes denisi (Schenkel, 1963) in having a similar long ridge-shaped proximal cymbial apophysis of the cymbium in the male palp and a broad scape, almost hexagonal in shape in the epigynum, but can be distinguished by the following characters: (1) Lower margin of distal arm of the paracymbium with a projection, wider than long with a blunt end and covering the posterior margin of the tibia in retrolateral view in the new species (Figs 1A-D , 2A, B ), whereas the projection of the lower margin of the distal arm in D. deni is longer than wide with a pointed end and not covering the posterior margin of the tibia (Fig. 5A, B ); (2) Anterior projection of the lamella characteristica (ALC) leaf-shaped with pointed end, protruding above the tegulum and the posterior projection of the lamella characteristica (PLC) as long as the ALC with pointed end (Figs 1A-D , 2A, B ), whereas ALC short, almost equal to the suprategulum (ST) with pointed end and PLC long, almost touching the anterior terminal apophysis (ATA) in D. denisi (Fig. 5A, B ); (3) Anterior terminal apophysis (ATA) strongly curved with blunt end and pointing towards ALC in new species (Figs 1A-D , 2A, B ), whereas slightly curved with pointed end and pointing towards the tegulum in ventral view in D. denisi (Fig. 5A, B ); (4) Posterior terminal apophysis (PTA) triangular in the new species (Figs 1A , 2A ), whereas it is tongue-shaped in D. denisi ( Tu et al. 2005, figs 16, 17; Fig. 5A, B ). (5) Female posterior median plate (PMP) tetragonal shape in the new species (Fig. 3D ), whereas it is hexagonal in D. denisi (Fig. 6C ).

Description.

Male (holotype, HNU-00-Lan-1): Total length: 2.57. Carapace 1.06 long, 0.97 wide, cephalic region slightly elevated, brown, fovea, cervical and radial grooves distinct. Clypeus 0.35 high. Sternum wider than long, brown, with spine-like setae; labium wider than long; maxillae long, distal-end broad with scopulae. Chelicerae with 5 retromarginal teeth, promarginal teeth absent. Eye region narrow, AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.06, ALE 0.08, PME 0.09, PLE 0.08, AME-AME 0.03, PME-PME 0.05, AME-ALE, 0.08, PME-PLE 0.07, AME-PME 0.06, ALE-ALE 0.40, PLE-PLE 0.43, ALE-PLE contiguous. Length of legs: I 5.89 (1.48, 1.91, 1.53, 0.97), II 5.03 (1.31, 1.57, 1.31, 0.84), III 3.9 (1.12, 1.19, 0.97, 0.62), IV 5.32 (1.49, 1.61, 1.38, 0.84). Leg formula (longest to shortest legs): I-IV-II-III. TmI 0.66 and TmIV 0.48. Tibial spine formula: 2-2-2-2. Abdomen 1.51 long, 0.94 wide, oval, light grey, with distinct pattern on dorsal surface from proximal end to base of spinnerets and extending laterally, ventral side green. Palp (Figs 1A-D , 2A, B ): patella short, with long dorsal spine; tibia conic, with two retrolateral and one dorsal trichobothria; paracymbium U-shaped, basal part with several setae, lower margin of distal arm with a projection, wider than long with a blunt end, covering the posterior margin of tibia in retrolateral view; cymbium rather long, ridge-shaped, proximal to cymbial apophysis (PCA). Pit hook curved with a pointed end. Embolic division: Radix long, sclerotized; anterior projection of lamella characteristica (ALC) leaf-shaped with a pointed end, protruding above tegulum; posterior projection of lamella characteristica (PLC) as long as ALC with a pointed end; terminal apophysis sclerotized, dark, strongly curved with a blunt end, pointing towards anterior projection of lamella characteristica (ALC). Embolus short, tip bifurcated; apical margin of thumb (TH) serrated, median membrane simple.

Female (paratype HNU-00-Lan-2): Total length: 3.16. Carapace 1.26 long, 0.92 wide; cephalic region slightly elevated, dark brown; fovea, cervical and radial grooves distinct. Clypeus 0.31 high. Sternum wider than long, brown, with spine-like setae; labium wider than long; maxillae long, distal-end broad with scopulae. Chelicerae with 4 promarginal and 3 retromarginal teeth. Eye region narrow, AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.07, ALE 0.09, PME 0.08, PLE 0.08, AME-AME 0.02, PME-PME 0.05, AME-ALE, 0.06, PME-PLE 0.06, AME-PME 0.06, ALE-ALE 0.39, PLE-PLE 0.41, ALE-PLE contiguous. Length of legs: I 5.55 (1.49, 1.82, 1.39, 0.85), II 4.8 (1.32, 1.55, 1.21, 0.72), III 3.83 (1.09, 1.27, 0.92, 0.55), IV 5.18 (1.46, 1.63, 1.33, 0.76). Leg formula I-IV-II-III. TmI 0.58 and TmIV 0.43. Tibial spine formula: 2-2-2-2. Abdomen 1.90 long, 1.16 wide; oval, light grey, dorsally with distinct pattern from proximal end to base of spinnerets and extending laterally, ventral side green. Epigynum (Fig. 3A-E ): broad, posteriorly pointing scape almost hexagonal-shaped, stretcher and lateral pockets absent; posterior median plate (PMP) conspicuously large, tetragonal-shaped, covering most of dorsal side of scape; spermathecae elliptical.

Etymology.

The species name comes from the Latin adjective " Denisiphantes arcuatus " meaning “curved” and refers to the curved anterior terminal apophysis in the male palp.

Distribution.

Known only from the type locality in Yunnan, China (Fig. 8 ) .

Figures

Figure 1. Denisiphantes arcuatus sp. nov., male holotype palp A prolateral view B retrolateral view C ventral view D dorsal view.

Figure 2. Denisiphantes arcuatus sp. nov., male holotype palp. A prolateral view B retrolateral view.

Figure 3. Denisiphantes arcuatus sp. nov., female paratype A, C epigynum, ventral view B epigynum, lateral view D vulva, dorsal view E vulva, anterior view.

Figure 4. Denisiphantes arcuatus sp. nov., male holotype (A, B) and female paratype (C-D) A, C habitus, dorsal view B, D habitus, ventral view.

Figure 5. Denisiphantes denisi (Schenkel, 1963) A palp, ventral view B palp, retrolateral view.

Figure 6. Denisiphantes denisi (Schenkel, 1963) A, B epigynum, ventral view C vulva, dorsal view D vulva, anterior view.

Figure 8. Distribution of Denisiphantes arcuatus sp. nov. and Denisiphantes denisi (Schenkel, 1963).