Bisetocreagris chumi, Feng & Zhang & Chen, 2023

Feng, Zegang, Zhang, Feng & Chen, Jun, 2023, Cave-dwelling Neobisiidae in South China Karst, with descriptions of twelve new species of Bisetocreagris (Pseudoscorpiones, Neobisiidae) from Guizhou Province, Zootaxa 5395 (1), pp. 1-77 : 28-34

Bisetocreagris chumi sp. nov. (Ë*双ŁÞ伪AE)

http://zoobank.org:act: 7E885FE7-4C72-4171-899F-18596B98D384

Figs 22–26

Type material. Holotype male (Ps.- MHBU-GZ19072801 ): China, Guizhou Province, Zunyi City, Tongzi County, Chumi Town, Chumi Village, Tufei Cave (âṅåǎ义Ṅḋṋ县ṵ*Dzṵ*ť土匪ñ), [28°15′03.14″N, 106°50′49.81″E], 1388 m a.s.l., 28 July 2019, Zegang Feng, Zhaoyi Li, Chen Zhang leg.

Paratypes: 10 males (Ps. -MHBU-GZ19072802‒11 ) , 7 females (Ps. -MHBU-GZ19072812‒18 ), all with the same data as the holotype .

Etymology. Named after the Chumi Village (ṵ*ť), near the type locality; noun in apposition.

Distribution and habitat. This new species is known only from the type locality Tufei cave ( Figs 1J , 22 ), located in Liangfengya Forest Park, Chumi Village, Chumi Town. The entrance is arched (height ~ 20 m, width ~ 30 m) and surrounded by stone-piled walls. The cave is moist, about 200 m long, extends downwards into a slope, and is scattered with a number of large stones. All specimens were collected on the wall between the twilight to dark zone ( Figs 22C‒D ). Huntsman spiders of the family Sparassidae were recorded as predators for this species ( Fig. 23C ).

Diagnosis. (♂ ♀). Troglomorphic habitus; carapace with 2 eyespots; epistome triangular, with rounded tip; carapace with 6–8 setae on posterior margin; pedipalp smooth and slender except for hand, which is finely granular, both chelal fingers with 123–142 teeth; femur 6.37–6.78 times (length 2.10–2.29), patella 4.80–5.54 times (length 1.93–2.18) longer than wide, pedicel about half the total length of patella. Hand with pedicel 2.76–2.98 (♂), 2.66– 2.82 (♀) times (length 1.61–1.74), chela with pedicel 5.92–6.29 (♂), 5.51–5.95 (♀) times (length 3.42–3.65) longer than wide, finger 1.20–1.29 times longer than hand with pedicel. Chelicera: rallum with 8–9 pinnate setae, distal one with an expanded base, distal-most 2–3 blades slightly separated from others, proximal one short.

Description. Male (holotype; paratypes males in parentheses; Figs 23A , 24A ). Carapace, chelicerae, and pedipalps reddish brown; abdomen and legs yellowish.

Carapace ( Figs 25A , 26A–B ): smooth, 1.28 (1.22–1.26) times longer than wide, with a total of 27 (26–30) setae, including 4 (4) on anterior margin, 6 (6–8) on posterior margin, and 2–3 (2–3) on each side of antero-lateral margin; with 2 eyespots on slightly raised surface ( Fig. 25B ); epistome small and triangular, with rounded tip.

Chelicera ( Figs 25C , 26B–C, E ): hand with 6 (6–7) setae, movable finger with 1 (1) submedial seta; fixed finger with 12–17 (13–17) teeth; movable finger with 12–13 (11–16) teeth; serrula exterior with 37 (36) lamellae; serrula interior with 27 (28) lamellae. Galea ( Fig. 26E ) divided into 2–3 main branches, and each branch is divided into multiple sub-branches. Rallum ( Fig. 26C ) with 8 (8–9) pinnate blade, distal-most blade with an expanded base, distal-most 2 blades slightly separated from others, proximal one short.

Pedipalps ( Figs 25D–E , 26I–K ): apex of coxae rounded, with 5 (4–5) setae on each side, pedipalpal coxae with 6–7 (6–9) setae. Pedipalp smooth and slender except for hand, which is finely granular. Trochanter 2.79 (2.56–2.81) times longer than wide, femur 6.72 (6.52–6.78), patella 5.26 (4.80–5.41) times longer than wide, pedicel about half the entire length of patella, chela (with pedicel) 6.00 (5.92–6.29), chela (without pedicel) 5.49 (5.36–5.78) times longer than wide, movable finger 1.42 (1.49–1.56) times longer than hand (without pedicel). Fixed chelal finger with 8 trichobothria, movable finger with 4, eb and esb on lateral margin of hand; ib, ist and isb closely grouped at the base of the fixed finger; est slightly distal of finger middle; it closer to fingertip than et; on movable finger st nearer to t than to sb, the distance between sb and b longer than that of st between t, the distance between b and s b longer than that of st between t ( Figs 25D , 26I–J ). Venom apparatus present only in fixed chelal finger, venom duct short, not extending past half of the distance to et. Fixed chelal finger with 136 (134–142) teeth, which are flat and retrorse in distal and middle part, blunt and round in basal part; movable finger with 125 (128–132) teeth, which are flat and retrorse in distal part, blunt and round in middle and basal part; all teeth contiguous.

Abdomen: pleural membrane granulated. Tergal chaetotaxy (I–XI): 7:8:7:8:9:9:9:9:10:8:7 (7–10:8–10:7–9:8– 9:8–9:9–10:9–10:8–10:9–10:9–12:6–9); sternal chaetotaxy (V–XI): 10:15:14:15:16:16:14:4 (10–11:17–18:16– 18:14–18:15–18:14–15:12–14:3–4); stigmata with 6 (5–8) setae; anal cone with 2 dorsal and 2 ventral setae. Male genital area ( Figs 25F , 26G ): sternite II with 42 (44–62) scattered setae; sternite III with anteromedian groove flanked by one small seta on each side, with 22 (21–28) posterior setae.

Legs: coxae chaetotaxy (I–IV): 8–9:7–8:4:9 (8–10:7–9:3–4:9–11). Leg I ( Figs 25H , 26L ): femur 5.62 (5.30– 6.20), patella 4.22 (3.43–4.44), tibia 8.15 (7.43–8.08), basitarsus 4.00 (3.92–4.25), telotarsus 5.21 (5.58–6.45) times longer than wide, femur 1.55 (1.51–1.69) times longer than patella, telotarsus 1.52 (1.34–1.43) times longer than basitarsus.

Leg IV ( Figs 25I , 26F, M ): femur + patella 6.60 (5.14–6.69) times longer than wide, femur shorter than patella, tibia 10.16 (9.55–10.78), basitarsus 4.79 (4.33–4.86), telotarsus 6.14 (5.93–7.00) times longer than wide, telotarsus 1.28 (1.27–1.34) times longer than basitarsus; basitarsus with one tactile setae (TS=0.15), telotarsus with one tactile setae (TS=0.54–0.56); subterminal tarsal seta ( Fig. 26F ) bifurcate, both branches dentate; arolium not divided, shorter than the slender and simple claws.

Females (paratypes; Figs 23B , 24B ): mostly same as holotype and paratypes males.

Chelicera. Hand with 5–7 setae, movable finger with 1 submedial seta; fixed finger with 12–16 teeth; movable finger with 11–18 teeth; serrula exterior with 37–42 lamellae; serrula interior with 27–29 lamellae. Galea divided into 2–3 main branches, and each one branch divided into multiple sub-branches; rallum of 8–9 blades, distal-most blade with expanded base, distal-most 2–3 blades slightly separated from others, proximal one short.

Pedipalps. Apex of coxae rounded, with 4–5 setae on each side. Pedipalpal coxae with 7–8 setae. Trochanter 2.49–2.70, femur 6.37–6.77, patella 4.88–5.54, chela (with pedicel) 5.51–5.95, chela (without pedicel) 5.02–5.41 times longer than wide, movable finger 1.45–1.54 times longer than hand (without pedicel). Fixed chelal finger with about 133–140 teeth, movable finger with about 123–132 teeth.

Abdomen. Tergal chaetotaxy (I–XI): 8–12:8–10:7–9:8–9:9–10:9–10:9–10:10–11:9–10:9–10:6–7; sternal chaetotaxy (IV–XI): 8–11:16–20:17–18:15–19:16–19:15–18:11–16:4–5. Female genital area ( Figs 25G , 26H ): sternite II with 5–8 setae on each side; sternite III with a row of 13–18 setae on the posterior margin.

Measurements: (length/breadth or depth in mm; ratios for most characters in parentheses). Holotype male (paratypes males in square brackets). Body length 5.33 [3.03–5.50]. Carapace 1.28/1.00 (1.28) [1.22–1.26/0.97– 1.03 (1.22–1.26)]. Pedipalpal trochanter 0.95/0.34 (2.79) [0.92–1.01/0.34–0.36 (2.56–2.81)], femur 2.15/0.32 (6.72) [2.15–2.23/0.32–0.34 (6.52–6.78)], patella 2.00/0.38 (5.26) [1.97–2.09/0.37–0.41 (4.80–5.41)], chela (with pedicel) 3.42/0.57 (6.00) [3.43–3.65/0.55–0.59 (5.92–6.29)], chela (without pedicel) 3.13/0.57 (5.49) [3.13–3.35/0.55–0.59 (5.36–5.78)], hand length (without pedicel) 1.42 [1.34–1.43], movable finger length 2.02 (1.42 times longer than hand without pedicel) [2.04–2.20 (1.49–1.56 times longer than hand without pedicel)]. Leg I: trochanter 0.35/0.25 (1.40) [0.35–0.40/0.24–0.25 (1.44–1.60)], femur 1.18/0.21 (5.62) [1.21–1.24/0.20–0.23 (5.30–6.20)], patella 0.76/0.18 (4.22) [0.72–0.80/0.18–0.21 (3.43–4.44)], tibia 1.06/0.13 (8.15) [1.04–1.06/0.13–0.14 (7.43–8.08)], basitarsus 0.48/0.12 (4.00) [0.47–0.51/0.12 (3.92–4.25)], telotarsus 0.73/0.14 (5.21) [0.65–0.73/0.11–0.12 (5.58– 6.45)]. Leg IV: trochanter 0.59/0.26 (2.27) [0.61–0.70/0.25–0.27 (2.44–2.65)], femur + patella 1.98/0.30 (6.60) [1.90–2.00/0.29–0.37 (5.14–6.69)], tibia 1.93/0.19 (10.16) [1.89–1.94/0.18–0.20 (9.55–10.78)], basitarsus 0.67/0.14 (4.79) [0.65–0.68/0.14–0.15 (4.33–4.86)], telotarsus 0.86/0.14 (6.14) [0.83–0.91/0.13–0.14 (5.93–7.00)].

Females (paratypes). Body length 3.58–5.75. Carapace 1.29–1.36/1.01–1.11 (1.20–1.28). Pedipalpal trochanter 0.92–1.00/0.37–0.38 (2.49–2.70), femur 2.10–2.29/0.31–0.35 (6.37–6.77), patella 1.93–2.18/0.38–0.41 (4.88– 5.54), chela (with pedicel) 3.46–3.63/0.61–0.65 (5.51–5.95), chela (without pedicel) 3.17–3.30/0.61–0.65 (5.02– 5.41), hand length (without pedicel) 1.38–1.45, movable finger length 2.09–2.18 (1.45–1.54 times longer than hand without pedicel). Leg I: trochanter 0.36–0.41/0.25–0.27 (1.38–1.54), femur 1.18–1.3/0.21–0.23 (5.36–6.10), patella 0.70–0.80/0.19–0.20 (3.68–4.16), tibia 0.98–1.13/0.13–0.15 (7.00–7.85), basitarsus 0.48–0.52/0.12–0.13 (3.85– 4.00), telotarsus 0.71–0.74/0.13–0.14 (5.21–5.69). Leg IV: trochanter 0.64–0.72/0.26–0.29 (2.46–2.73), femur + patella 1.84–2.02/0.30–0.36 (5.11–6.43), tibia 1.75–2.00/0.19–0.20 (9.21–10.53), basitarsus 0.63–0.70/0.15–0.16 (3.94–4.67), telotarsus 0.84–0.90/0.14–0.15 (5.60–6.43).

Remarks. Bisetocreagris chumi sp. nov. resembles B. cavernarum Mahnert et Li, 2016 , B. chinacavernicola ( Schawaller, 1995) , B. guangshanensis Gao et Zhang, 2017 , B. maomaotou Gao, Wynne et Zhang, 2018 and B. xishui sp. nov. in having a similar pedipalp shape. The new species differs from B. cavernarum by the presence of 2 eyespots on the slightly raised surface of carapace (vs. B. cavernarum with 4 small eyes, 2 anterior eyes with indistinct lens); the pedipalpal femur 6.37–6.78 (♂ ♀) times longer than wide (vs. 5.82 (♂), 5.83 (♀) times in B. cavernarum ), and the patella 4.80–5.54 (♂ ♀) times longer than wide (vs. 4.34 (♂), 4.67 (♀) times in B. cavernarum ).

The new species differs from B. chinacavernicola by the pedipalpal femur 6.37–6.78 (♂ ♀) times longer than wide (vs. 6.00 (♂), 5.61 (♀) times in B. chinacavernicola ), patella 4.80–5.54 (♂ ♀) times longer than wide (vs. 4.69 (♂), 4.75 (♀) times in B. chinacavernicola ), the chela (without pedicel) 5.36–5.78 (♂), 5.02–5.41 (♀) times longer than wide (vs. 4.85 (♂), 4.41 (♀) times in B. chinacavernicola ); and the presence of fine granulations on pedipalp chelal hand (vs. smooth in B. chinacavernicola ).

Bisetocreagris chumi sp. nov. can be distinguished from B. guangshanensis by the pedipalpal femur 6.37–6.78 (♂ ♀) times longer than wide (vs. 5.32–5.70 (♂), 5.32–5.59 (♀) times in B. guangshanensis ), the patella 4.80– 5.54 (♂ ♀) times longer than wide (vs. 3.89–4.41 (♂ ♀) times in B. guangshanensis ), the chela (without pedicel) 5.36–5.78 (♂), 5.02–5.41 (♀) times longer than wide (vs. 4.41–4.79(♂ ♀) times in B. guangshanensis ); and the presence of fine granulations on pedipalp chelal hand (vs. all segments except chela with scale-like sculptured in B. guangshanensis ).

Bisetocreagris chumi sp. nov. differs from B. maomaotou by the presence of 2 eyespots on the slightly raised surface of carapace (vs. B. maomaotou without eyes or eyespots); the female pedipalpal femur 6.37–6.77 times longer than wide (vs. 5.20 times in B. maomaotou ), patella 4.88–5.54 times longer than wide (vs. 4.30 times in B. maomaotou ) and chela (without pedicel) 5.02–5.41 times longer than wide (vs. 4.24 times in B. maomaotou ); and the presence of fine granulations on pedipalp chelal hand (vs. femur with granulations basally, chelal hand with fine granulations on medial face in B. maomaotou ).

Bisetocreagris chumi sp. nov. differs from B. xishui sp. nov. by: the pedipalpal femur 6.52–6.78 (♂), 6.37–6.77 (♀) vs. 5.58–5.82 (♂), 5.66 (♀) times longer than wide, patella 4.80–5.41 (♂), 4.88–5.54 (♀) vs. 4.53–4.60 (♂), 4.60 (♀) times longer than wide in B. xishui sp. nov.; the chela (with pedicel) 5.92–6.29 (♂), 5.51–5.95 (♀) vs. 5.34–5.48 (♂), 5.29 (♀) times longer than wide in B. xishui sp. nov.; and the presence of fine granulations on pedipalp hand (vs. medial of hand and base of femur, which is finely granulated in B. xishui sp. nov.).

This new species is similar in pedipalpal proportions to B. jiangi sp. nov., but can be distinguished by the presence of fine granulations on pedipalp hand (vs. smooth in B. jiangi sp. nov.); the apex of coxae with 7–8 setae on each side (vs. with 4–5 setae in B. jiangi sp. nov.); and the position of trichobothrium that it distinctly closer to fingertip than et (vs. it -et at same level near fingertip in B. jiangi sp. nov.).

Figures

FIGURE 1. Distribution map of the type locality of troglomorphic Bisetocreagris species in China. A. B. maomaotou Gao, Wynne et Zhang, 2018 (Maomaotou Cave); B. B. que sp. nov. (Yanggong Cave); C. B. longidigitata sp. nov. (Mao’er Cave); D. B. brevis sp. nov. (Yehu Cave); E. B. aspera sp. nov. (Tu Cave); F. B. jiangi sp. nov. (Anjialin Cave); G. B. tenuipalma sp. nov. (Sanjie Cave); H. B. changbing sp. nov. (Sanyuan and Guanyin caves); I. B. ampla sp. nov. (Hei Cave); J. B. gracilenta Gao et Zhang, 2017 (Shanmu Cave); K. B. guangshanensis Gao et Zhang, 2017 (Guangshan Cave); L. B. chumi sp. nov. (Tufei Cave); M. B. sanmen sp. nov. (Sanmen Cave); N. B. xishui sp. nov. (Dongkoushang Cave); O. B. baozinensis Mahnert et Li, 2016 (Baozi Cave); P. B. chuanensis Mahnert et Li, 2016 (Chuan Cave); Q. B. grandis sp. nov. (Wulibeidadong Cave); R. B. scaura (Mahnert, 2003) (Dahei Cave); S. B. martii (Mahnert, 2003) and B. titania (Mahnert, 2003) (Guoquan Cave); T. B. xiaoensis Li et Liu, 2017 (Xiao Cave); U. B. juanxuae Mahnert et Li, 2016 (Dao Cave); V. B. cavernarum Mahnert et Li, 2016 (Ert Long Cave); W. B. chinacavernicola (Schawaller, 1995) (Xian Nin and Chao-Tian caves).

FIGURE 22. Tufei Cave, type locality of Bisetocreagris chumi sp. nov. A‒B. Entrances (A: Outside the entrance; B: Inside the entrance); C. The twilight zone of the Tufei Cave, the area where the first B. chumi sp. nov. specimen was collected; D. Area where B. chumi sp. nov. specimens were collected.

FIGURE 23. Live individuals of Bisetocreagris chumi sp. nov. (A: male; B: female) under the ground and on the rock, respectively; C. B. chumi sp. nov. like a preyed spider of the family Sparassidae.

FIGURE 24. Bisetocreagris chumi sp. nov., A. Holotype male, dorsal view; B. Paratype female, dorsal view.

FIGURE 25. Bisetocreagris chumi sp. nov., holotype male (A–F, H–I), female (G). A. Carapace, dorsal view; B. Eye area, lateral view; C. Right chelicera, dorsal view; D. Right chela, lateral view; E. Right pedipalp, dorsal view; F. Male genitalia; G. Female genitalia; H. Right leg I, lateral view; I. Right leg IV, lateral view.

FIGURE 26. Bisetocreagris chumi sp. nov., holotype male (A–G, I–M), female (H). A. Carapace, dorsal view; B. Right chelicera, dorsal view; C. Rallum; D. Movable finger of chelicera, showing galea; E. Galea; F. Subterminal tarsal seta; G. Male genitalia, ventral view; H. Female genitalia, ventral view; I. Right chela, dorsal view; J. Right chelal fingers, retrolateral view; K. Right pedipalp, minus chela, dorsal view; L. Right leg I, lateral view; M. Right leg IV, lateral view. Scale bars: 0.1 mm (C–D, F), 0.25 mm (B, G–H), 0.5 mm (A, J), 1 mm (I, K–M).