Stenohya arcuata, Guo, Zang & Fe. Zhang, 2019

Guo, Xiangbo, Zang, Xiao & Zhang, Feng, 2019, Two New Stenohya Species (Pseudoscorpiones: Neobisiidae) From The Gaoligong Mountains, Southwestern China, Acta Zoologica Academiae Scientiarum Hungaricae 65 (2), pp. 95-105 : 96-100

Stenohya arcuata sp. n.

( Figs 1–3)

Type material. Holotype male (Ps.- MHBU-YN14041301 ), China: Yunnan Province, Baoshan City, Gaoligong Mountains (25°18’N, 98°47’E), alt. 2345 m, 13 April 2014, leg. Xuankong Jiang. Paratypes: one male and three females (Ps.-MHBU- YN14041302–05), collected with holotype .

Etymology. The specific name is derived from the Latin word “ arcuatus ”, meaning

“arched”, refers to the incurved pedipalpal femur and patella in male.

Diagnosis. Carapace with 4 well-developed eyes, epistome triangular; apex of pedipalpal coxa with 4 long setae; male pedipalpal femur and patella incurved (female pedipalpal femur straight, patella curved at base); male pedipalpal femur 5.44–5.56 (female 4.23–4.45), patella 3.38–3.49 (female 2.81–2.86), chela (with pedicel) 4.83–4.97 (female 3.50–3.74) times longer than broad; male fixed chelal finger with 137–141 (female 124–129) small, cusped teeth; movable finger with 120–124 (female 115–118) small teeth.

Description of males ( Fig. 1a) – Carapace and abdomen almost black, pedipalps, chelicera and legs brown. Setae of body straight and acicular.

Carapace ( Figs 2a, 3a). Entirely smooth, 1.14–1.16 times longer than broad, with total of 30 setae, including 8 near anterior margin and 6 near posterior margin; 3–4 lyrifissures near the eyes; epistome triangular; with 4 corneate eyes.

Chelicera ( Figs 2e, 3d). Hand with 6 setae and 2 lyrifissures, movable finger with 1 seta situated sub-medially; fixed finger with 14–16 teeth; movable finger with 8 teeth; serrula exterior with 37 lamellae; serrula interior with 30–32 lamellae; galea with 6 terminal rami ( Fig. 2c); rallum consisting of 8 blades, all with anteriorly-directed spinules, the basalmost blade shortest ( Fig. 2f).

Pedipalps ( Figs 2b, 2g, 3b, 3c). Apex of pedipalpal coxa rounded, with 4 long setae. Femur incurved, with several tubercles prolaterally; patella incurved, smooth; chelal hand with coarse granulation on medial surface near the base of fixed chelal finger; trochanter 1.43–1.83, femur 5.44–5.56, patella 3.38–3.49, chela (with pedicel) 4.83–4.97, chela (without pedicel) 4.57–4.64 times longer than broad, movable finger 1.50 times longer than hand (with pedicel). Fixed chelal finger with 8, movable finger with 4 trichobothria: eb, esb, ib and isb located basally, et, est and it situated distally, ist almost at middle of fixed finger; trichobothria t and st in distal fourth, b and sb in basal fourth of movable finger. Venom apparatus present only in fixed chelal finger, duct very short. Fixed chelal finger with 137–141 small, cusped teeth, movable finger with 120–124 small teeth, cusped only in distal tenth of finger.

Abdomen. Pleural membrane granulated. Tergites and sternites undivided, tergal chaetotaxy (I–XI): 8–9: 12: 11–12: 12: 12–14: 12: 10: 10–11: 12: 11: 5, sternal chaetotaxy (IV– XI): 22–24: 25: 22: 23: 21: 17–19: 16: 12; in addition, sternites VI–VIII with 7–9 medial scattered glandular setae; sternite III with 8, sternite IV with 7 setae along anterior margin of each stigmata; anal cone with 2 dorsal and 2 ventral setae. Genital area ( Figs 2j, 3e): sternite II with total of 46–49 setae and 2 lyrifissures; sternite III with 13 setae and 2 lyrifissures anteriorly, 25–26 setae on posterior margin. Genitalia with 8 setae on posterior genital plate.

Legs. Leg I ( Figs 2h, 3g) and leg IV ( Figs 2i, 3h) typical. Tibia IV with a sub-medial tactile seta (TS = 0.67–0.70), basitarsus IV with 2 tactile setae situated basally and distally (TS = 0.07, 0.85), telotarsus IV with a sub-medial tactile seta (TS = 0.60). Subterminal tarsal seta with 3 branches; arolium not divided, shorter than the slender, simple claws.

Description of females ( Fig. 1b) – As in holotype, except where noted.

Chelicera. Fixed finger with 14 teeth; movable finger with 7 teeth; serrula exterior with 35–37 lamellae; serrula interior with 28–29 lamellae; galea with 7 terminal rami ( Fig. 2d).

Pedipalps. Femur straight, with several tubercles prolaterally; patella smooth, curved at base; chela smooth; trochanter 1.63–1.73, femur 4.23–4.45, patella 2.81–2.86, chela (with pedicel) 3.50–3.74, chela (without pedicel) 3.27–3.54 times longer than broad, movable finger 1.34–1.39 times longer than hand (with pedicel); fixed chelal finger with 124–129 small, cusped teeth, movable finger with 115–118 small teeth, cusped only in distal fifth of finger.

Abdomen. Tergal chaetotaxy (I–XI): 6: 8–9: 11–12: 12: 12: 11–12: 12: 12: 13–14: 13: 8, sternal chaetotaxy (IV–XI): 21–22: 26: 22: 22–24: 22: 20: 17–18: 13; in addition, sternites VI– lateral view; i = right leg IV, lateral view (subterminal seta magnified); j = genital area; k =

genital area. Scale bars: 0.10 mm (c, d, f); 0.50 mm (a, e, j, k); 1.00 mm (b, g–i)

VIII with 2 medial glandular setae. Genital area ( Figs 2k, 3f): sternite II with 24–25 setae and 2 lyrifissures; sternite III with a row of 36 setae along posterior margin.

dorsal view; b = right pedipalp, dorsal view; c = right chela, lateral view; d = right chelicera, dorsal view; e = genital area; f = genital area; g = right leg I, lateral view; h = right leg IV,

lateral view

Measurements (in mm; ratios in parentheses are length/breadth or, for legs, length/ depth). Male. Body length 3.86–3.94. Carapace 1.16–1.35/1.02–1.11 (1.14–1.16×). Chelicera 0.80–0.84/0.43 (1.86–1.95×), movable finger length 0.57–0.60. Pedipalpal trochanter 0.70– 0.86/0.47–0.49, femur 2.00–2.12/0.36–0.39, patella 1.52–1.64/0.45–0.47, chela (with pedicel) 3.18–3.48/0.64–0.72, chela (without pedicel) 2.97–3.29/0.64–0.72, hand (with pedicel) 1.27–1.37/0.64–0.72 (1.90–1.98×), movable finger length 1.91–2.05. Leg I: trochanter 0.36– 0.41/0.27–0.29 (1.33–1.41×), femur 0.90–1.01/0.19–0.23 (4.39–4.74×), patella 0.59–0.64/0.18– 0.20 (3.20–3.28×), tibia 0.75–0.83/0.14–0.15 (5.36–5.53×), basitarsus 0.43–0.46/0.11 (3.91– 4.18×), telotarsus 0.54–0.56/0.09–0.11 (4.91–6.22×). Leg IV: trochanter 0.53–0.65/0.26–0.27 (2.04–2.41×), femur + patella 1.55–1.65/0.39–0.40 (3.88–4.23×), tibia 1.29–1.44/0.21 (6.14– 6.86×), basitarsus 0.55–0.58/0.13–0.15 (3.87–4.23×), telotarsus 0.79–0.84/0.12–0.13 (6.46– 6.58×).

Female. Body length 5.12–6.08. Carapace 1.24–1.30/1.16–1.35 (0.96–1.07×). Chelicera: 0.98–1.02/0.53–0.54 (1.85–1.89×), movable finger length 0.69. Pedipalpal trochanter 0.76– 0.91/0.44–0.56, femur 1.96–2.20/0.44–0.52, patella 1.46–1.63/0.52–0.57, chela (with pedicel) 3.40–3.60/0.91–1.03, chela (without pedicel) 3.22–3.37/0.91–1.03, hand (with pedicel) 1.42– 1.55/0.91–1.03 (1.50–1.56×), movable finger length 1.97–2.07. Leg I: trochanter 0.40–0.45/0.30– 0.35 (1.29–1.33×), femur 0.98–1.07/0.22–0.26 (4.12–4.45×), patella 0.63–0.69/0.21–0.23 (3.00×), tibia 0.81–0.86/0.16–0.18 (4.78–5.06×), basitarsus 0.45–0.49/0.13–0.14 (3.46–3.50×), telotarsus 0.60/0.11–0.12 (5.00–5.45×). Leg IV: trochanter 0.76–0.80/0.33–0.35 (2.17–2.42×), femur + patella 1.72–1.79/0.40–0.46 (3.89–4.30×), tibia 1.46–1.56/0.22–0.27 (5.78–6.64×), basitarsus 0.59–0.65/0.16–0.17 (3.69–3.82×), telotarsus 0.91–0.93/0.14–0.15 (6.20–6.50×).

Distribution. China (Yunnan).

Remarks. An incurved pedipalpal femur of the type observed in the male of the new species also occurs in the male of S. setulosa from Tibet, China. Stenohya arcuata can be distinguished from S. setulosa by the following combination of characters: apex of pedipalpal coxa with 4 long setae (versus 3 long setae and 10–12 short setae, forming into two rows in S. setulosa ); fixed chelal finger with 137–141 teeth (versus 97–105 in S. setulosa ) and movable finger with 120–124 teeth (versus 78–87 in S. setulosa ).