Belisana zham Yao & Li, 2020

Zhu, Wenhui, Yao, Zhiyuan, Zheng, Guo & Li, Shuqiang, 2020, The Belisana spiders (Araneae: Pholcidae) from Tibet, China, Zootaxa 4802 (1), pp. 111-128 : 121-127

Belisana zham Yao & Li sp. nov.

Figs 9–10 , 11 G–H

Type material. Holotype: Male ( IZCAS Ar39813), Zham Town (27°59 ꞌ 01.05 ꞌꞌ N, 85°58 ꞌ 58.32 ꞌꞌ E, elevation 2450 ± 3 m), Nyalam County, Xigaze, Tibet, China, 29 July 2014, Y. Li leg. Paratypes: 2 males ( IZCAS Ar39814–39815) and 4 females ( IZCAS Ar39816–39819), same data as holotype .

Etymology. The specific name refers to the type locality and is a noun in apposition.

Diagnosis. This species resembles B. xigaze sp. nov. ( Figs 7–8 , 11 E–F) and B. yadongensis ( Hu, 1985) (see Zhang et al. 2006: 203, figs 41–50) with similar male chelicerae ( Fig. 10D ), but can be distinguished by procursus that is not protruding dorso-subdistally ( Figs 9 A–B), by absence of retrolateral membranous flap on procursus ( Fig. 9D ), by presence of large, triangular, disto-retrolateral membranous lamella on procursus (arrow in Fig. 9D ) and by having slender bulbal apophysis ( Fig. 10C ). It can also be distinguished from B. xigaze sp. nov. by absence of black lateral margins but presence of pair of large brown marks on carapace ( Figs 10 E–F). It differs from B. yadongensis by having pore plates that are nearly elliptic in shape ( Figs 10B , 11H ).

Description. Male (holotype, IZCAS Ar39813): Total length 2.25 (2.38 with clypeus), carapace 1.02 long, 0.80 wide, opisthosoma 1.23 long, 1.01 wide. Leg I: 11.90 (2.75 + 0.36 + 2.78 + 4.38 + 1.63), leg II: 8.02 (2.19 + 0.29 + 2.13 + 2.97 + 0.44), leg III: 4.98 (1.47 + 0.13 + 1.25 + 1.72 + 0.41), leg IV: 6.85 (2.03 + 0.25 + 1.41 + 2.75 + 0.41); tibia I L/d: 56. Habitus as in Figs 10 E–F. Carapace pale, with pair of large brown marks; ocular area with brown stripe medially; sternum pale, without marks. Legs pale, without darker rings. Opisthosoma pale, with black spots dorsally and laterally. Distance PME-PME 0.11, diameter PME 0.06, distance PME-ALE 0.04, AME absent. Ocular area not elevated. Thoracic furrow absent. Clypeus unmodified. Sternum slightly wider than long (0.75/0.68). Chelicerae ( Fig. 10D ) with pair of small proximo-lateral apophyses and pair of long, curved distal apophyses each with hardened and pointed tip (distance between tips: 0.46). Pedipalps as in Figs 9 A–B; coxa unmodified; trochanter with short retrolatero-ventral apophysis; femur without proximo-dorsal apophysis; procursus ( Figs 9 A–D) simple proximally and complex distally, with sclerites, spine, and large, triangular, disto-retrolateral membranous lamella (arrow in Fig. 9D ); bulb ( Fig. 10C ) with hooked apophysis and simple embolus. Retrolateral trichobothria of tibia I at 8% proximally; legs with short vertical setae on metatarsi, without spines or curved setae; tarsus I with 24 distinct pseudosegments.

Female (IZCAS Ar39816): Similar to male, habitus as in Figs 10 G–H. Total length 2.31 (2.38 with clypeus), carapace 0.82 long, 0.69 wide, opisthosoma 1.49 long, 1.41 wide. Tibia I: 4.45; tibia I L/d: 31. Distance PME-PME 0.10, diameter PME 0.05, distance PME-ALE 0.05, AME absent. Sternum slightly wider than long (0.58/0.45). Carapace only with dark radiated lines; ocular area without median stripe. External female genitalia ( Figs 10A , 11G ) simple and flat, with pair of pockets 0.38 apart (ep in Figs 10 A–B, 11G–H). Vulva ( Figs 10B , 11H ) with roof-shaped anterior arch and pair of small, nearly elliptic pore plates.

Variation: Leg I missing in male paratypes ( IZCAS Ar39814–39815). Tibia I in two female paratypes ( IZCAS Ar39817–39818; leg I missing in the other female paratype IZCAS Ar39819): 4.17, 4.55 .

Natural history. The species was found on the underside of rocks.

Distribution. China (Tibet, type locality only; Fig. 12 ).

Figures

FIGURE 7. Belisana xigaze sp. nov., holotype male. A–B. Pedipalp (A. Prolateral view, arrow points at dorsal protruding part of procursus; B. Retrolateral view); C–D. Distal part of procursus (C. Prolateral view; D. Retrolateral view). b = bulb, e = embolus, f = flap, pr = procursus. Scale bars: 0.10 (A–B), 0.05 (C–D).

FIGURE 8. Belisana xigaze sp. nov., holotype male (C–F) and paratype female (A–B, G–H). A. External female genitalia, ventral view; B. Vulva, dorsal view; C. Bulb, prolateral view; D. Chelicerae, frontal view; E–H. Habitus (E, G. Dorsal view; F. Lateral view; H. Ventral view). b = bulb, ba = bulbal apophysis, da = distal apophysis, e = embolus, ep = epigynal pocket, pa = proximo-lateral apophysis, pp = pore plate. Scale bars: 0.05 (A–D), 0.40 (E–H).

FIGURE 9. Belisana zham sp. nov., holotype male. A–B. Pedipalp (A. Prolateral view; B. Retrolateral view); C–D. Distal part of procursus (C. Prolateral view; D. Retrolateral view, arrow points at large, triangular, disto-retrolateral membranous lamella). b = bulb, ba = bulbal apophysis, e = embolus, pr = procursus. Scale bars: 0.10 (A–B), 0.05 (C–D).

FIGURE 10. Belisana zham sp. nov., holotype male (C–F) and paratype female (A–B, G–H). A. External female genitalia, ventral view; B. Vulva, dorsal view; C. Bulb, prolateral view; D. Chelicerae, frontal view; E–H. Habitus (E, G. Dorsal view; F. Lateral view; H. Ventral view). b = bulb, ba = bulbal apophysis, da = distal apophysis, e = embolus, ep = epigynal pocket, pa = proximo-lateral apophysis, pp = pore plate. Scale bars: 0.05 (A–D), 0.40 (E–H).

FIGURE 11. Drawings of female genitalia in ventral and dorsal views. A–B. B. gyirong Zhang, Zhu & Song, 2006; C–D. B. muruo sp. nov.; E–F. B. xigaze sp. nov.; G–H. B. zham sp. nov. ep = epigynal pocket, pp = pore plate. Scale bars: 0.10.

FIGURE 12. Distribution records of five species of the genus Belisana. 1. B. gyirong Zhang, Zhu & Song, 2006; 2. B. medog sp. nov.; 3. B. muruo sp. nov.; 4. B. xigaze sp. nov.; 5. B. zham sp. nov.