Xizangiana xiangbi Liu & Zhang, 2023

Liu, Bo, Wang, Luyu & Zhang, Feng, 2023, Revision of the genus Xizangiana Sherwood, Li & Zhang, 2022, with descriptions of five new species (Araneae: Gnaphosidae), Zootaxa 5346 (4), pp. 443-468 : 454-457

Xizangiana xiangbi Liu & Zhang , sp. n.

(ƦẠqǥ)

Figs 2K–L , 3B , 9–12

Type material. Holotype ♁ (MHBU-ARA-2014-56-1), CHINA: Yunnan Province, Baoshan City, Longyang District, Gaoligong Mountain , 25°17.311N, 98°47.308´E, 1671 m elev., 22 April 2014, leg. XuanKong Jiang. Paratype: 4♀ (MHBU-ARA-2014-56-2 to 5), 2♁ (MHBU-ARA-2014-56-6 to 7), same data as holotype; 2♁ (MHBU-ARA-2014-55-1 to 2), same data as previous except 25°18.092N, 98°47.401´E, 1793 m elev., 21 April 2014 .

Etymology. The species name comes from the Chinese word “Xiangbi”, which means the elephant trunk, referring to the long and thin scape of the epigyne of the new species ( Fig. 12A ); noun in apposition.

Diagnosis. Male differs from all congeners by the following combination of characters: presence of a tegulum bump, a spine-like radix projection, a hook-like retrolateral embolar base projection, and the absence of terminal membrane ( Figs 10–11 ). Female can be distinguished from all congeners by the following combination of characters: the presence of long and thin scape, with a ratio of length to width more than 2, the weakly sclerotized anterior fold, transversal folds less than four, weakly sclerotized, and the incomplete anterior parts of the lateral folds ( Fig. 12 ).

Description. Male. Total length 2.95–4.26. Holotype ( Fig. 9C–D ; MHBU-ARA-2014-56-1): total length 4.04; carapace 1.76 long, 1.35 wide; abdomen 2.28 long, 1.32 wide. Eye sizes and interdistances: AME 0.08, ALE 0.11, PME 0.06, PLE 0.08; AME‒AME 0.02, AME‒ALE 0.02, PME‒PME 0.06, PME‒PLE 0.03, ALE‒PLE 0.04. Leg measurements: I 4.84 (1.44, 0.75, 1.17, 0.82, 0.66), II 3.80 (1.12, 0.58, 0.85, 0.66, 0.59), III 3.18 (0.95, 0.47, 0.66, 0.59, 0.51), IV 4.98 (1.42, 0.58, 1.13, 1.20, 0.65). Leg formula: 4123. Cheliceral promargin with five teeth, retromargin with three ( Fig. 2L ). Color in alcohol ( Fig. 9C–D ): carapace light brown; legs light brown.

Palp ( Figs 3B , 10–11 ). Retrolateral tibial apophysis distally curved, with an arc-shaped membranous projection dorsally; tegulum with a ventral bump; embolar radix and embolar base fused with tegulum; radix projection spine-like; embolar base with a hook-like retrolateral embolar base projection distally; embolus broad, slightly curved at retrolaterally, apex with membranous outgrowth; median apophysis guitar-shaped in ventral view.

Female. Total length 3.38–3.77. One paratype ( Fig. 9A–B ; MHBU-ARA-2014-56-2): total length 3.32; carapace 1.65 long, 1.22 wide; abdomen 1.67 long, 1.03 wide. Eye sizes and interdistances: AME 0.07, ALE 0.09, PME 0.07, PLE 0.08; AME‒AME 0.01, AME‒ALE 0.01, PME‒PME 0.04, PME‒PLE 0.02, ALE‒PLE 0.03. Leg measurements: I 3.63 (1.11, 0.52, 0.87, 0.59, 0.54), II 3.26 (0.99, 0.49, 0.76, 0.56, 0.46), III 2.94 (0.87, 0.39, 0.58, 0.62, 0.48), IV 4.27 (1.18, 0.55, 0.95, 0.98, 0.61). Leg formula: 4123. Chelicerae ( Fig. 2K ) as in male. Color in alcohol ( Fig. 9A–B ) as in male.

Epigyne ( Fig. 12 ). Atrium U-shaped, with four weakly sclerotized transversal folds; anterior fold with well sclerotized anterior and weakly sclerotized posterior parts; scape long and thin having a ratio of length to width more than 2; anterior parts of the lateral folds incomplete; posterior parts of the lateral folds chevron-like, well sclerotized; secondary spermathecae globular, small.

Remarks. Xizangiana xiangbi sp. n. is unique among other known species of this genus by its distribution in Gaoligong Mountain, rather than in Himalayas. The absence of terminal membrane on bulb, the embolar radix and embolar base both fused with tegulum indicate that X. xiangbi sp. n. could be the sister group of other known Xizangiana species.

Distribution. China (Yunnan) ( Fig. 23 ).

Figures

FIGURE 2. Chelicerae, ventral view. A–B. X. linzhiensis, female (A) and male (B); C–D. X. namchabarwa sp. n., female (C) and male (D); E. X. rigaze, male. F–H. X. shenxian sp. n., female (F–G) and male (H); I–J. X. benae sp. n., female (I) and male (J); K–L. X. xiangbi sp. n., female (K) and male (L); M–O. X. longlin sp. n., male (M–N) and female (O); Scale bars = 0.1 mm.

FIGURE 3. RTA, retrolateral view. A. X. linzhiensis; B. X. xiangbi sp. n.; C. X. namchabarwa sp. n.; D. X. shenxian sp. n.; E. X. longlin sp. n.; F. X. rigaze; G. X. benae sp. n.. Scale bars = 0.05 mm.

FIGURE 9. Xizangiana xiangbi sp. n., female (A–B) and male (C–D). Habitus, in dorsal (A, C) and ventral (B, D) view. Scale bars = 0.5 mm.

FIGURE 10. Xizangiana xiangbi sp. n.. A–B. Palp, in ventral (A) and retrolateral (B) view; C. RTA, retrolateral view; D–F. Bulb, in prolateral (D), ventral (E) and retrolateral (F) view.

FIGURE 11. Expanded palp of Xizangiana xiangbi sp. n., in prolateral (A) and retrolateral (B) view.

FIGURE 12. Female genitalia of Xizangiana xiangbi sp. n., in ventral (A) and dorsal (B) view.

FIGURE 23. Records of Xizangiana species: 1 X. pawani comb. n.; 2 X. sedula comb. n.; 3 X. shenxian sp. n.; 4 X. rigaze; 5 X. benae sp. n.; 6 X. longlin sp. n.; 7 X. linzhiensis; 8 X. namchabarwa sp. n.. 9 X. xiangbi sp. n..