Eusimonia turkestana Kraepelin, 1899

Fan, Wenlong, Zhang, Chao & Zhang, Feng, 2024, First report of the family Karschiidae (Arachnida, Solifugae) from Gansu Province, China, with description of two new species, Zootaxa 5492 (3), pp. 369-394 : 371-379

publication ID	https://doi.org/ 10.11646/zootaxa.5492.3.5
publication LSID	lsid:zoobank.org:pub:8CBBFFB6-24C8-45EB-B71B-CA636A8AD05F
DOI	https://doi.org/10.5281/zenodo.13234919
persistent identifier	https://treatment.plazi.org/id/03F00D6B-FF9D-FFE3-4994-FA2AAC94F9CF
treatment provided by	Plazi
scientific name	Eusimonia turkestana Kraepelin, 1899
status

Treatment

Eusimonia turkestana Kraepelin, 1899 View in CoL

Figures 1 View FIGURE 1 , 4–7 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 , 16F, G View FIGURE 16 , 17A View FIGURE 17 . Table 1 View TABLE 1 , 2.

Type material. Holotype ♂, Central Asia (as Turkestana in the original description), stored at ZMB (the Zoological Museum , Museum for Naturkunde, Berlin, Germany), not examined.

Material examined: 1♂ (MHBU-Sol-GS2019071101), CHINA: Gansu Province, Guazhou County, Gansu Anxi Extreme Drought Desert National Nature Reserve , 40.1317°N, 95.8667°E, ca 1610m elev., 11.VII.2019, leg. Xinglong Bai GoogleMaps ; 1♂ (MHBU-Sol-GS2023070601), CHINA: Gansu Province, Guazhou County, Gansu Anxi Extreme Drought Desert National Nature Reserve , 40.1307°N, 95.8652°E, ca 1530m elev., 6.VII.2023, leg. Wenlong Fan GoogleMaps ; 3♂♂ 1♀ (SWUC-Sol-GS2023070101–04), CHINA: Gansu Province, Minqin County, Lanhu Town, Suwu Desert , 38.2687°N, 103.2717°E, ca 1440m elev., 1.VII.2023, leg. Wenlong Fan GoogleMaps ; 9♂♂ 10♀♀ (MHBU-Sol-GSJLL01–19) CHINA: Gansu Province, Linze County, Pingchuan Town, Yigongcheng Village , 39.3359°N, 100.0977°E, ca 1320m elev., leg. Jiliang Liu GoogleMaps ; 3♀♀ (SWUC-Sol-GS2019071601–03), CHINA: Gansu Province, Aksay Kazakh Autonomous County, Annanba Wild Camel National Nature Reserve , 39.2361°N, 92.3392°E, ca 2240m elev., 16.VII.2019, leg. Xinglong Bai. GoogleMaps

Description. Male (MHBU-Sol-GS2019071101).

Measurements. Total body length 11.48, CH 1.13, CL 4.07, CW 0.71, PL 1.56, PW 2.23, A/CP 6.55, CL/ CH 3.60. Pedipalp 11.73 (2.68, 3.24, 2.83, 1.04), leg Ⅰ 9.62 (2.16, 2.52, 1.71, 0.94, 0.06), leg II 9.63 (1.79, 2.25, 1.82, 0.63, 0.71), leg III 11.47 (2.44, 2.56, 1.96, 0.82, 0.73), leg IV 15.53(3.86, 4.68, 1.37, 0.86, 0.82).

Coloration. In 95% ethanol-preserved specimens ( Figs 4A, B View FIGURE 4 ). Prosoma general background yellow, and opisthosoma general background black. Propeltidium tan with brown on either side of ocular tubercle, densely covered with short yellowish-brown setae and sparsely with long tawny setae; ocular tubercle black ( Fig. 5D View FIGURE 5 ). Opisthosoma densely covered with yellowish-brown setae dorsally, abdominal tergites and sclerites black. Chelicera yellow, covered with long brownish setae; each terminal tooth of fixed finger and movable finger reddish ( Figs 5A, B View FIGURE 5 ), pedipalps and legs yellowish-brown except coxa and trochanter, covered with brownish setae. Malleoli white.

Propeltidium. Wider than long ( Fig. 5D View FIGURE 5 ), with a dense pubescence of thin, short, anteriorly directed fine setae; median eyes separated by less than one diameter; propeltidium lobe without eyespot. Anterior, posterior, and lateral edges with several long, curved spiniform setae perpendicular to the surface of the propeltidium. Ocular tubercle with a row of proximal spiniform setae, a row of short and two long middle distal spiniform setae. On each side of ocular tubercle, propeltidium with strong spiniform setae ( Fig. 5D View FIGURE 5 ).

Chelicerae. Fixed finger with median teeth series comprising well-developed primary teeth ( FP, FM and FD), FD tooth size lesser, while FM and FP similar in size ( Figs 5A–C View FIGURE 5 , 7A, B View FIGURE 7 ); moreover, median teeth series comprising all secondary teeth (1 FSD and 2 FSM); secondary teeth overall size smaller than primary teeth, distal FSM smaller than proximal FSM. Retrofondal teeth series uninterrupted with five teeth (1 RFP, 1 RFM, 3 RFA), and profondal teeth series consisting of four teeth (1 PFSP, 1 PFP, 1 PFSM, 1 PFM) ( Fig. 5C View FIGURE 5 ). Fixed finger asetose area sinuous, with ventral margin predominantly linear in lateral aspect; prodorsal carina not sharp, not elevated in lateral aspect ( Figs 5A–C View FIGURE 5 ). Cheliceral fixed finger hornlike process curved with two teeth ( Fig. 5C View FIGURE 5 ), mucron without subterminal ( FST) teeth, and apex ( FT tooth) curved, hook-shaped ( Fig. 5C View FIGURE 5 ). Movable finger with median teeth series comprising well-developed MP and MM primary teeth, the former of which larger, and two MSM secondary tooth smaller than MM (i.e., MP > MM > MSM), movable finger one MSM teeth close to MP, another one close to MM, MSM upright and triangular-shaped; movable finger without subproximal ( MSP) or subterminal ( MST) teeth. ( Figs 5A, B View FIGURE 5 ) Retrolateral and dorsal surfaces with abundant retrolateral manus (rlm) and retrolateral finger (rlf) setae, of different sizes, which are predominantly straight and rigid; some of these setae arranged in bilaterally symmetrical pattern, as some principal retrolateral finger (principal rlf) setae that more flexible than others ( Figs 5A View FIGURE 5 , 7A View FIGURE 7 ); prolateral surface with array of setal types ( Figs 5B View FIGURE 5 , 7B View FIGURE 7 ), as follows: proventral distal (pvd) setae consisting of row of strong setae, starting at level of the flagellum and ending near level of PFM tooth; proventral subdistal (pvsd) setae arranged in rather disorganized pattern, pvsd comb not markedly differentiated; carpet-like field of bristle-like promedial (pm) setae broad. Stridulatory plate longer than high, occupying most of the prolateral surface of manus, above stridulatory plate two prodorsal proximal (pdp) setae exist; stridulatory apparatus not obvious. Distal limit of the prolateral setose area of movable finger reaching midpoint between MSM and MM teeth; movable finger prodorsal (mpd) setal series consisting of spinous setae arranged in a rather staggered row, adjacent to abundant non-plumose setae of the movable finger promedial (mpm) and proventral (mpv) setal series ( Figs 5B View FIGURE 5 , 7B View FIGURE 7 ). Flagellum typical of Eusimonia , bear two distinct, membranous or weakly sclerotized, sessile flagella: a broad, thin, dorsal secondary flagellum and a tubelike ventral primary flagellum ( Figs 5A–C View FIGURE 5 , 7A, B View FIGURE 7 , 17A View FIGURE 17 ); flagellum without flagellar complex subspiniform to spiniform (fcs) setae; membranous dorsal flagellum (secondary flagellum) narrow triangular-shaped without central depression ( Fig. 5C View FIGURE 5 ).

Opisthosoma. The entire surface covered with almost adpressed fine setae, and numerous long, curved, bifurcate setae, and tergites with abundant setae. Sternite III with 5+5 coarse and spiny ctenidia reach the distal border of the sternite III ( Figs 5E View FIGURE 5 , 7E View FIGURE 7 ), sternite IV with a row of 13 long and thin peg-like ctenidia, almost reach the distal border of the sternite Ⅴ ( Figs 5F View FIGURE 5 , 7F View FIGURE 7 ).

Pedipalps. Entirely covered with short fine setae and long, thick setae. Tarsus without spines; posterior half of metatarsus thickens inward, resembling a hump, with six quite strong, distally diminishing, forward-inclined spines which thicker and flattened at distal ends ( Figs 7C, D View FIGURE 7 , 16F, G View FIGURE 16 ).

Legs. Leg I coated with abundant short setae similar to those on pedipalps, without stout or spiniform setae; tibia and metatarsus with few long thin setae, tarsus without spiniform setae; with two small claws. Tibiae II and III with one distal spiniform setae dorsally and a pair of distal spiniform setae ventrally. Metatarsi II and III with a series of three dorsal spiniform setae and a pair of distal spiniform setae ventrally; metatarsus IV ventrally with two distal spiniform setae and three to five thick, spine-shaped bristles arranged in a prolateral row. Legs covered with long, thick setae and short fine setae. Distal part of claw short, occupying approximately 1/5 of the claw length.

Female (MHBU-Sol-GS2023070101)

Measurements. Total body length 12.78, CH 1.62, CL 4.43, CW 1.46, PL 2.20, PW 3.06, A/CP 5.43, CL/ CH 2.73. Pedipalp 11.80 (2.91, 3.13, 2.848, 1.19), leg Ⅰ 8.43 (2.48, 1.86, 1.47, 0.83, 0.05), leg II 8.69 (1.67, 1.76, 1.67, 0.47, 0.54), leg III 10.24 (2.23, 2.74, 1.34, 0.37, 0.51), leg IV 15.77 (3.72, 4.08, 1.56, 0.67, 1.05).

Coloration. In 95% ethanol-preserved specimens ( Figs 4C, D View FIGURE 4 ). Coloration mostly like male, but opisthosoma general background light chartreuse.

Propeltidium. Mostly the same as male, but female ocular tubercle spiniform setae on each side of ocular tubercle not as strong as in male ( Fig. 6D View FIGURE 6 ).

Chelicera. Fixed finger with median teeth series comprising well-developed primary teeth (FP, FM and FD), FD tooth size smaller, while FM and FP similar in size ( Figs 6A–C View FIGURE 6 , 7G, H View FIGURE 7 ); moreover, median teeth series comprising all secondary teeth (2FSD and 2 FSM); secondary teeth overall size smaller than primary teeth, distal FSD and FSM smaller than proximal FSD and FSM. Retrofondal teeth series uninterrupted with eight teeth (4RFSP, 1RFP, 1RFM, 2RFA); profondal teeth series consist of five teeth (1PFP, 1PFSM, 2PFSP, 1PFM) ( Fig. 6C View FIGURE 6 ). Fondal teeth graded as II, III, IV, I, VII, VI, VIII, V retrolaterally; II, I, III, V, IV prolaterally ( Fig. 6C View FIGURE 6 ). Fixed finger mucron without subterminal (FST) teeth. Movable finger with median teeth series comprising well-developed MP and MM primary teeth, the former of which larger, and three MSM and two MSP secondary teeth that smaller than MM (i.e., MP> MM> MSM> MSP), movable finger MSM teeth located MM and MP center, MST teeth located MM front, and MSP located MP after; all secondary teeth upright and triangular-shaped ( Figs 6A, B View FIGURE 6 , 7G, H View FIGURE 7 ). Cheliceral setose areas and stridulatory plate mostly like male, but female proventral distal (pvd) setae only consisting of row of plumose setae ( Figs 6B View FIGURE 6 , 7H View FIGURE 7 ).

Opisthosoma. The entire surface covered with almost adpressed fine setae and numerous long, curved, bifurcate setae. Genital operculum with clear demarcation between the plates, distal border widened, resembling a triangle shape. Genital opening not visible between plates or distal to plates. ( Figs 6E View FIGURE 6 , 7I View FIGURE 7 ). 15 long needle-like ctenidia on sternite IV extending the length of the following sternite ( Figs 6F View FIGURE 6 , 7J View FIGURE 7 ).

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

Legs. Same as in the male.

Distribution and habitat. E. turkestana is widely distributed in the arid regions of northwest China (Nei Mongol, Xinjiang), Kazakhstan and Mongolia. Habitat: Gobi Desert ( Fig. 2F View FIGURE 2 ) and desert steppe ( Fig. 2B View FIGURE 2 ). As Gromov (2003) mentioned, E. turkestana live in clayey, stony or sandy loam deserts at low altitudes.

Collection method. During the night using an ultra-violet lamp. Under ultraviolet light, Solifugae reflects a faint blue glow, making it easy to spot and catch. Given their nocturnal habits, we also collect specimens using pitfall traps.

Variability. Males. Total length 10.56–15.64. Body coloration light yellow to yellow. Chelicerae with manus yellowish to brown. The number of cheliceral fixed finger fondal teeth 9–11 (profondal teeth 4–5; retrofondal teeth 5–6). The number of ctenidia on sternite IV 13–15. Females. Total length 11.72–16.36. Variability of body coloration as in males. The number of cheliceral fixed finger fondal teeth 12–14 (profondal teeth 4–5; retrofondal teeth 7–9), MST 0–2, MSP 2–3. The number of ctenidia on sternite IV 14–15.

Remark. We matched both sexes based on DNA barcoding data, with a genetic distance between male and female voucher specimens ranging from 0%–4.11% ( Table 1 View TABLE 1 ). No distinct morphological differences were found among individuals of the same sex. After examining 30 adult specimens, we discovered a high intraspecific mitochondrial divergence in E. turkestana . Given that this species has a widespread distribution across Central Asia, this variability is especially prominent among specimens from various locations, indicating potential longterm adaptation and evolutionary processes within distinct geographical regions. The identification of this genetic diversity holds significant implications for comprehending the species' biogeographical distribution, population genetic structure, and evolutionary trajectory.