Parobisium magangensis, Feng & Wynne & Zhang, 2019

Feng, Zegang, Wynne, J. Judson & Zhang, Feng, 2019, Two new subterranean-adapted pseudoscorpions (Pseudoscorpiones: Neobisiidae: Parobisium) from Beijing, China, Zootaxa 4661 (1), pp. 145-160 : 147-152

Parobisium magangensis sp. n.

( Figs. 2–5 )

Type material. Holotype male (Ps.- MHBU-BJ 18061001 ): China, Beijing City, Fangshan District, Xiayunling Town , Magang Cave , [39.711342°N, 115.745130°E], estimated cave deep zone, 751 m elevation, 10 June 2018, Zegang Feng leg.

Paratypes: 1♁ (Ps.- MHBU-BJ 18061002 ), 7♀ (Ps.- MHBU-BJ 18061003 –09 ), same location as holotype .

Diagnosis. Troglomorphic habitus; carapace without eyes or eyespots; epistome rounded; carapace with 6 setae on posterior margin; pedipalp smooth and slender, both chelal fingers with 146–162 teeth; femur 8.91–8.97 times (length 2.78–2.94), patella 7.64–7.84 times (length 2.75–2.98) longer than broad, pedicel about two-thirds of total length of patella. Hand with pedicel 3.89–4.04 times (length 1.86–1.95), chela with pedicel 8.67–8.96 times (length 4.12–4.25) longer than broad, finger 1.18–1.23 times longer than hand with pedicel. Chelicera: rallum with 8–9 pinnate setae, distal one with an expanded base.

Description. Male ( Fig. 3A ). Carapace, chelicerae and pedipalps brown; abdomen and legs yellowish.

Carapace ( Figs 4A , 5A): Smooth, 1.19–1.31 times longer than broad, with a total of 22 setae, including 4 on anterior margin and 6 on posterior margin; lacks eyes or eyespots; epistome rounded.

Chelicera ( Figs 4B , 5B): Hand with 6 setae, movable finger with one submedial seta; fixed finger with 13–14 teeth; movable finger with 15–16 teeth; serrula exterior with 34–37 lamellae; serrula interior with 22–25 lamellae. Galea ( Fig. 5G ) replaced by a small rounded transparent spinneret. Rallum ( Fig. 5C ) with 8 pinnate setae, distal one separated and with expanded base, proximal one short.

Pedipalps ( Figs 4 C–D, 5H–I): Apex of coxa rounded, with 4 setae on each side. pedipalp smooth and slender. Trochanter 3.71–3.90, femur 8.91–8.97, patella 7.64–7.84, chela (with pedicel) 8.67–8.96, chela (without pedicel) 7.59–7.71 times longer than wide, movable finger 1.61–1.78 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 situated at the subdistal of finger; est, et and it grouped together near fingertip; b situated at base of movable finger, sb situated at one-third base of the finger, st and t at one-third distal of movable finger, st nearer to t than to sb, the latter nearer to b than to st, the distance between b and sb longer than that between t and st. Venom apparatus present only in fixed chelal finger, venom duct short. Fixed chelal finger with 146–148 teeth, movable finger with 160–162 teeth.

Abdomen: Pleural membrane granulated. Tergal chaetotaxy (I–XI): 6: 7–9: 8: 8: 8–10: 8–9: 9–11: 8–11: 10–11: 10–11: 6–7; sternal chaetotaxy (IV–XI): 10: 12–13: 11: 11: 11: 11: 11: 2–4; stigmata with 4–6 setae around; anal cone with 2 dorsal and 2 ventral setae. Male genital area ( Figs 4E , 5E): sternite II with 22 scattered setae; sternite III with 2–3 setae which occur on the intermediary and followed by 10 posterior setae.

Legs: Leg I ( Figs 4G , 5J) and Leg IV ( Figs 4H , 5K) typical. Tibia IV with one submedial tactile seta (TS = 0.54– 0.67), basitarsus IV with one basal tactile seta (TS = 0.14–0.16), telotarsus IV with one tactile seta (TS = 0.49–0.56). Subterminal tarsal seta ( Fig. 5F ) bifurcate; arolium not divided, shorter than the slender and simple claws.

Female (paratypes) ( Fig. 3B ): Mostly same as holotype.

Chelicera. Hand with 6 setae, movable finger with 1 submedial seta; fixed finger with 13–14 teeth; movable finger with 17–18 teeth; serrula exterior with 35–37 lamellae; serrula interior with 22–25 lamellae. Galea replaced by a small rounded transparent spinneret; rallum of 8 blades, similar to that of holotype.

Pedipalps. Trochanter 3.3–3.44, femur 7.53–8.18, patella 6.48–6.60, chela (with pedicel) 6.45–6.95, chela (without pedicel) 5.64–6.05 times longer than wide, movable finger 2.09–2.30 times longer than hand (without pedicel). Fixed chelal finger with 135–136 teeth, movable finger with 145–150 teeth.

Abdomen. Tergal chaetotaxy (I–XI): 6–8: 6–8: 7–9: 8–9: 8–10: 9–11: 9–11: 10–11: 10–12: 9–11: 6–9; sternal chaetotaxy (IV–XI): 8–10: 10–13: 10–13: 11–12: 11–12: 11–13: 10–12: 2–4. Female genital area ( Figs 3F , 4D ): sternite II with 2–3 setae on each side; sternite III with a row of 12 setae on the posterior margin.

Measurements: (length/breadth or depth in mm; ratios for most characters in parentheses). Male (holotype and paratypes). Body length 3.46–4.87. Carapace 1.19–1.31 (1.26–1.38/1.05–1.06). Pedipalpal trochanter 3.71–3.90 (1.21–1.26/0.34–0.31), femur 8.91–8.97 (2.78–2.94/0.31–0.33), patella 7.64–7.84 (2.75–2.98/0.36–0.38), chela (with pedicel) 8.67–8.96 (4.12–4.25/0.46–0.49), chela (without pedicel) 7.59–7.71 (3.55–3.72/0.46–0.49), hand length (without pedicel) 1.29–1.43, movable finger length 2.29–2.30 (1.61–1.78 times longer than hand without pedicel). Leg I: trochanter 1.60–1.68 (0.40–0.42/0.25), femur 6.81–7.89 (1.43–1.50/0.19–0.21), patella 5.06–5.21 (0.91–0.99/0.18–0.19), tibia 9.23–9.57 (1.20–1.34/0.13–0.14), basitarsus 5.36–5.50 (0.59–0.66/0.11–0.12), telotarsus 7.27–7.70 (0.77–0.80/0.10–0.11). Leg IV: trochanter 2.88–2.92 (0.70–0.72/0.24–0.25), femur + patella 7.39– 7.81 (2.03–2.29/0.26–0.31), tibia 9.94–11.10 (1.79–2.33/0.18–0.21), basitarsus 4.43–5.07 (0.62–0.76/0.14–0.15), telotarsus 7.15–7.42 (0.89–0.93/0.12–0.13).

Female (paratypes). Body length 4.32–5.88. Carapace 1.16–1.33 (1.41–1.45/1.06–1.25). Pedipalpal trochanter 3.36–3.44 (1.24–1.31/0.36–0.39), femur 7.53–8.18 (2.70–2.86/0.33–0.38), patella 6.48–6.60 (2.64–2.72/0.40–0.42), chela (with pedicel) 6.45–6.95 (4.13–3.96/0.57–0.64), chela (without pedicel) 5.64–6.05 (3.45–3.61/0.57–0.64), hand length (without pedicel) 1.35–1.39, movable finger length 2.09–2.30 (1.50–1.70 times longer than hand without pedicel). Leg I: trochanter 1.43–1.58 (0.40–0.41/0.26–0.28), femur 6.24–6.68 (1.31–1.47/0.21–0.22), patella 4.94–5.17 (0.84–0.93/0.17–0.18), tibia 8.86–9.00 (1.17–1.24/0.13–0.14), basitarsus 4.67–5.27 (0.56–0.58/0.11– 0.12), telotarsus 6.00–6.55 (0.72/0.11–0.12). Leg IV: trochanter 2.58–2.59 (0.62–0.75/0.24–0.29), femur + patella 7.21–7.31 (2.09–2.34/0.29–0.32), tibia 9.76–10.85 (2.05–2.17/0.20–0.21), basitarsus 4.79–4.87 (0.67–0.73/0.14– 0.15), telotarsus 6.14–6.71 (0.86–0.94/0.14).

Distribution. This species is currently known only from the type locality.

Etymology. Latinized adjective derived from the type locality for this species, Magang Cave.

Remarks. P. magangensis sp. n. resembles Parobisium longipalpus Hong, 1996 but is distinguished by the lack of eyes or eyespots ( P. longipalpus has four conspicuous eyes), chelal fingers with 146–162 teeth (about 84–99 teeth in P. longipalpus ), and a slender pedipalpal femur 8.91–8.97 longer than broad (3.6–4.9 times in P. longipalpus ), atella 7.64–7.84 times longer than broad (2.9–3.3 times in P. longipalpus ).

P. magangensis sp. n. differs from Parobisium robustiellum Hong, 1996 by lack of eyes or eyespots ( P. robustiellum has four eyes), chelal fingers with 146–162 teeth (about 51–66 teeth in P. robustiellum ), and a slender pedipalpal femur 8.91–8.97 longer than broad (2.5–3.6 times in P. robustiellum ), patella 7.64–7.84 times longer than broad (2.7–3.4 times in P. robustiellum ).

P. magangensis sp. n. can be easily distinguished from Parobisium anagamidense ( Morikawa, 1957) by the following characters: carapace without eyes or eye spots ( P. anagamidense with four reduced eyes), epistome rounded (absent in P. anagamidense ); chelal fingers with 146–162 teeth (about 86–90 teeth in P. anagamidense ); pedipalpal femur 8.91–8.97 longer than broad (4.0 times in P. anagamidense ), patella 7.64–7.84 times longer than broad (2.9 times in P. anagamidense ).

Figures

FIGURE 2. Parobisium magangensis sp. n., Female habitus.

FIGURE 3. Parobisium magangensis sp. n. A. Holotype male, dorsal view; B. Paratype female, dorsal view.

FIGURE 4. Parobisium magangensis sp. n., holotype male: A. Carapace (dorsal view); B. Right chelicerae (dorsal view); C. Right chela (lateral view); D. Right pedipalp (dorsal view); E. Genital area of male; F. Genital area of female; G. Right leg I (lateral view); H. Right leg IV (lateral view).

FIGURE 5. Parobisium magangensis sp. n., holotype male (A–C, E–K), female (D). A. Carapace, dorsal view; B. Right chelicera, dorsal view; C. Rallum; D. Genital area of female; E. Genital area of male; F. Subterminal tarsal seta; G. Movable finger of chelicerae, showing galea; H. Right pedipalp, dorsal view (trochanter, femur and patella); I. Right chelal, lateral view; J. Right leg I, lateral view; K. Right leg IV, lateral view. Scale bars: 0.1 mm (C–E), 0.25 mm (B, F), 0.5 mm (A, I, J), 1 mm (G, H).