Karschia (Karschia) shigatse sp. nov.

Figs 1, 5 A – D, 7 C, D, 10 A – D, 11 E, 12 E, 15 A – D, 16 I, J, 17 E, 18 E, 19 I, K, Tables 1, 2

Type material.

Holotype ♂ (MHBU - Sol-XZ 2022071501), China: Xizang, Shigatse Prefecture, Nyalam County, Mainqu Town, 28.6773 ° N, 86.1395 ° E, 4552.71 m elev., 15. VII. 2022, leg. Wenlong Fan. Paratype: 1 ♀ (MHBU - Sol-XZ 2023072101), China: Xizang, Shigatse Prefecture Gyirong County, Zheba Town, 29.1976 ° N, 85.3571 ° E, 4605.8 m elev., 21. VII. 2023, leg. Xiangbo Guo .

Etymology.

Noun in apposition taken from Shigatse Prefecture where this species was collected.

Diagnosis.

Karschia shigatse sp. nov. differs from K. nubigena by having fringed flagellum (Fig. 11 E), from K. tibetana, K. dingye sp. nov., K. lhasa sp. nov. and K. zhui sp. nov. by flagellum with lateral apophysis (Fig. 11 E), and from K. namling sp. nov. by wide cheliceral fixed finger mucron, and lateral apophysis of flagellum larger (Fig. 11 E). Female differs from other species by genital operculum equilateral subtriangular and with no clear demarcation between the plates. (Fig. 17 E).

Description.

Male. Holotype (MHBU - Sol-XZ 2022071501).

Measurements. Total body length 15.52, CL 4.88, CH 1.56, PL 2.26, PW 2.74, A / CP 7.24, CL / CH 3.14. Pedipalp 19.38 (5.35, 5.62, 4.12, 1.26), Leg I 13.51 (3.17, 3.90, 2.23, 1.02, 0.19), Leg II 10.95 (2.66, 2.33, 1.37, 0.92, 0.70), Leg III 16.87 (3.62, 4.59, 3.02, 0.54, 0.87), Leg IV 18.77 (4.71, 6.49, 4.71, 1.57, 1.31).

Coloration. In 95 % ethanol-preserved specimens (Fig. 5 A, B). The general background pale yellowish. The opisthosoma slightly darker, with black tergites and yellow around the black sternites. Propeltidium pale tan and tinged with pale brown. Ocular tubercle black. Mesopeltidium and metapeltidium with special black stripes. Chelicerae with manus predominantly yellowish, with some black areas, and a retrolateral view of chelicerae with three black longitudinal stripes. Pedipalps and legs pale yellow, legs III and legs IV tinged with pale brown on distal regions of femora and proximal parts of tibiae. Proximal regions of the pedipalpal femur, tibia, metatarsus, and tarsus tinged with brown. Malleoli yellow.

Propeltidium. Wider than long with a dense pubescence of thin, short, anteriorly directed setae. Anterior, posterior, and lateral edges with several long, curved spiniform setae that perpendicular to the surface of the propeltidium. Ocular tubercle with two middle distal spiniform setae and one middle spiniform setae (Fig. 7 C). Chelicerae. Fixed finger primary teeth graded as FP <FD <FM. Profondal teeth series with three tiny teeth; retrofondal teeth series with seven teeth. Dental formulation of fixed finger: FD - (2) - FM - (2) - FP - (7 RF) (3 PF). Fixed finger mucron without dorsal crest. Movable finger MP tooth about the same size as MM. Dental formulation of movable finger: MM - (2) - MP, with two tiny MSM and three MSP (Figs 10 A, 15 A). Flagellum coiled, fringed and sessile, with lateral apophysis. The flagellar complex includes two medium length fcp and two short, thick fcs (Figs 10 B, 11 E, 15 B). Retrolateral and dorsal surfaces of the manus with large, bifurcated tip setae and short, simple tip bristle-like setae; retrolateral and dorsal surfaces of the fixed finger with simple tip setae of different sizes. Retrolateral setose area reaching the FSM teeth; prolateral surface with an array of setal types (Figs 10 A, B, 15 A, B).

Opisthosoma. Entire surface covered almost adpressed setae, and numerous long, curved, bifurcate setae. Sternite III with 21 pine needle-like ctenidia (Fig. 19 I). Sternite IV with 15 long peg-like ctenidia, the length of which almost equal to half the width of the succeeding sternite (Fig. 19 K).

Pedipalps. Totally covered with short setae and long, thick setae. Tarsus with eight sturdy ventral spines; metatarsus with 10 ventral spines not arranged in pairs and with thin papillae (Fig. 16 I, J).

Legs. Totally covered with long, thick setae and short setae. Leg I with no spines and two small claws. Tibias II, III, and IV with a pair of distal spines ventrally. Tibias II and III with a single dorsal spine; metatarsi II and III with a series of three dorsal spines, a pair of distal spines ventrally, and some paired short, thick, spine-shaped bristles over their entire ventral surface. Metatarsus IV also with these paired bristles over its entire ventral surface and two distal spines ventrally.

Female. Paratype (MHBU - Sol-XZ 2023072101).

Measurements. Total body length 24.17, CL 6.84, CH 2.47, PL 2.63, PW 3.73, A / CP 4.97, CL / CH 2.77. Pedipalp 16.57 (4.08, 4.48, 3.50, 1.24), Leg I 12.72 (3.69, 3.37, 2.04, 0.97, 0.19), Leg II 10.86 (1.86, 2.41, 1.91, 0.75, 0.61), Leg III 13.77 (2.44, 3.29, 2.24, 0.72, 0.83), Leg IV 17.75 (4.07, 4.08, 2.61, 1.44, 0.78).

Coloration. In 75 % ethanol-preserved specimens (Fig. 5 C, D). Coloration as in the males.

Propeltidium. Much wider than long with a dense pubescence of thin, short, anteriorly directed setae. Anterior, posterior, and lateral edges with several long, curved spiniform setae that perpendicular to the surface of the propeltidium. Ocular tubercle with four middle distal spiniform setae and three middle spiniform setae arranged in a triangle shape (Fig. 7 E).

Chelicerae. Dental formulation of fixed finger: FD - (2) - FM - (2) - FP - (8 RF) (5 PF). Dental formulation of movable finger: MM - (2) - MP, with four MST and two MSP. Fondal teeth graded as II, III, V, VI, VII, I, IV, tiny VIII retrolaterally; I, II, III, IV, V prolaterally (Figs 10 C, D, 12 E, 15 C, D).

Opisthosoma. The entire surface covered with almost adpressed setae and numerous long, curved, bifurcate setae. Genital operculum equilateral subtriangular and with no clear demarcation between the plates. The rear edge of the genital sternite not chitinized (Fig. 17 E). Sternite IV with 17 long needle-like ctenidia extending a half of the length of the succeeding sternite (Fig. 18 E).

Pedipalps. Totally covered with short setae and long, thick setae and without spines.

Legs. As in the males.

Distribution and habitat.

China (Xizang). Habitat: desert grassland (Fig. 2 E – G).

Remark.

Based on the comparison of genetic distances, with a genetic distance of 2.20 % (Table 2) between male and female collected from different near locations, we believe that they are same species.