Atemnus niger sp. nov.

(Figs 1 B–D, 5–7)

http://zoobank.org/ 40DA90C0-B2C6-40B0-8EBA-3F8378BD32CD

Type Material. Holotype male (Ps.- MHBU-XJ18072805), China, Xinjiang Uygur Autonomous Region, Changji Hui Autonomous Prefecture, Manas County, Taxihe Town, Hongshawan Village [44.105873°N, 86.345400°E], 765 m a.s.l., 1 August 2018, Zhizhong Gao and Weitong Wang leg.

Paratypes: six males (Ps.- MHBU-XJ18080107–12), one female (Ps.- MHBU-XJ18080113) and one male (ZMH-A0013067), same data as holotype .

Etymology. The name niger in Latin means “black” and refers to the dark carapace and tergites.

Diagnosis. The new species differs from A. limuensis by the slender pedipalpal femur of males (2.68–2.79 times longer than deep vs 2.22–2.55 times in A. limuensis) and by the pedipalpal trochanter with a conical dorsal tubercle (pedipalpal trochanter with two distinct coniform protuberances in A. limuensis); from A. politus by the stouter pedipalpal patella of females (2.33 times longer than deep vs 2.67–2.86 times in A. politus) and by the stouter leg IV of males (femur + patella 2.64–2.68 times longer than deep vs 3.04–3.20 times in A. politus); from A. letourneuxi by the slender pedipalpal femur of males (2.68–2.79 times longer than wide vs 2.20 times in A. letourneuxi) and by the presence of distinct granulation on the prolateral surface of the pedipalpal patella; from A. strinatii by having strong granulation on the pedipalpal femur and by having distinct eyespots; from A. syriacus by the slender pedipalp of males (femur 2.68–2.79 times longer than deep, patella 2.13–2.17 times, chela with pedicel 2.85–3.03 times, chela without pedicel 2.62–2.74 times, hand without pedicel 1.44–1.47 times vs femur 2.1 times, patella 1.7 times, chela with pedicel 2.6 times, chela without pedicel 2.3 times in A. syriacus) and by the lack of a brown transverse band on the carapace.

Description. Male (Fig. 5A). Carapace and abdomen dark brown, pedipalp deep reddish-brown, legs light yellow; body setae acuminate and long.

Carapace (Figs 6A, 7A): Smooth, with two distinct eyespots, without transverse furrow, with 48 setae, including 6 on anterior margin and 10 on posterior margin, the anterior half darker than the posterior half.

Chelicerae (Fig. 7B): Hand with 4 setae, bs dentate apically, es short, is and ls long and acute, fixed finger with 4 retrorse teeth and 2 small apical teeth, movable finger with a long, tooth-like subapical lobe; with two lyrifissures on hand; galea (Fig. 7C) long (shorter than female), with 6 branchlets; rallum (Fig. 7E) with 4 blades, the distal one anteriorly dentated; serrula exterior 22–23 lamellae.

Pedipalps (Figs 6B, 7F): The retrolateral surface of pedipalpal trochanter, the prolateral surface of pedipalpal femur, patella and hand granular, especially femur strongly; trochanter with a conical dorsal tubercle; fixed finger (Fig. 7I) with about 24–26 marginal teeth, movable finger with about 34–36 marginal teeth; trochanter 1.82–1.87, femur 2.68–2.79, patella 2.13–2.17, chela (with pedicel) 2.85–3.03, chela (without pedicel) 2.62–2.74 times longer than deep, movable finger 0.89–0.88 times longer than hand (without pedicel). Venom duct short, nodus ramosus between trichobothria et and est, but near et. st closer to sb than to t, t in the middle of movable finger; on fixed chelal finger, est midway between ist and it, distance between est and esb nearly equal to that of ist and isb, est at the equal level of t, distance between it and fingertip nearly equal to distance between ist and isb.

Abdomen: Tergites I–III and XI undivided and other tergites incompletely divided; half tergites with 5–6 marginal setae, and with big setae spots; tergal chaetotaxy: 8: 9: 8: 5–5: 5–4: 5–5: 5–6: 6–5: 6–6: 6–4 (8 + 4T): 9 + 2T; sternites XI undivided and other sternites divided, each half sternite with 2–3 lyrifissures and 6–8 marginal setae; sternal chaetotaxy (IV–XI): 5–3: 5–6: 6–7: 6–7: 7–6: 7–7: 6–5 (7 + 4T): 7 + 4T, anterior genital operculum (Figs 6D, 7K) with 5 setae on each side; posterior genital sternite with 10 setae; male genitalia (Fig. 7L): the distal part (l) of lateral apodemes sclerotized, especially the lateral border, and the hooked branch (b) bowed distally, terminated in a plate-like tip, the proximal part with a distinct dark sclerotized bar (c); the longitudinal fold of medial diverticula (d) with a projection midway along its length; the ejaculatory canal atrium (e) not well-developed; the lateral rods (f) long and diverging proximally; the tip of dorsal apodeme (g) identified as two minute spikes lying side by side; the ventral diverticulum (h) bilobed.

Legs: Leg I (Figs 6E, 7M) and leg IV (Figs 6H, 7G) typical. Fairly smooth, claws simple, longer than arolium, subterminal seta acute and curved. Leg IV with one tactile seta at the base of tarsus (Fig. 6F) (TS = 0.13–0.15).

Female (paratype) (Fig. 5B): Mostly same as the male holotype.

Chelicerae. Hand with 4 setae, fixed finger with 4 large retrorse teeth; galea (Fig. 7D) long with 6 branchlets; serrula exterior with 24 lamellae; rallum with 4 blades.

Pedipalps. Fixed finger with about 29 marginal teeth, movable finger with about 34 marginal teeth; trochanter 1.76, femur 2.59, patella 2.33, chela (with pedicel) 2.83, chela (without pedicel) 2.60 times longer than deep, movable finger 0.77 times longer than hand (without pedicel).

Abdomen. Tergites I–III and XI undivided and other tergites incompletely divided; tergal chaetotaxy: 11: 12: 11: 7–6: 6–6: 6–6: 7–5: 6–6: 7–7: 6–6 (8 + 4T): 11 + 2T; sternites divided, sternal chaetotaxy (IV–XI): 5–6: 4–7: 7–6: 7–7: 7–9: 9–9: 6–7 (9 + 4T): 10 + 4T; genital area (Figs 6G, 7J) with 5 setae on the anterior genital operculum and 12 setae on posterior margin, genital structure (Fig. 7H) simple, spermathecae provided with separated median cribriform plates.

Dimensions (length/breadth or depth, in mm). Males. Body length 2.37–2.47. Carapace 0.71–0.77/0.62–0.63 (1.15–1.22). Pedipalp: trochanter 0.40–0.43/0.22–0.23 (1.82–1.87), femur 0.67/0.24–0.25 (2.68–2.79), patella 0.64–0.65/0.30 (2.13–2.17), chela (with pedicel) 1.11–1.15/0.38–0.39 (2.92–2.95), chela (without pedicel) 1.02–1.04 (2.67–2.68), hand length (without pedicel) 0.56 (1.44–1.47), movable finger length 0.49–0.50 (0.88–0.89 times longer than length of hand without pedicel). Leg I: femur 0.23/0.16–0.17 (1.35–1.44), patella 0.37–0.38/0.15–0.16 (2.38–2.47), tibia 0.38/0.11–0.12 (3.17–3.45), tarsus 0.33–0.36/0.07–0.08 (4.50–4.71). Leg IV: femur + patella 0.66–0.67/0.25 (2.64–2.68), tibia 0.51–0.54/0.15 (3.40–3.60), tarsus 0.38–0.40/0.10 (3.80–4.00).

Female. Body length 2.32. Carapace 0.79/0.79 (1.00). Pedipalp: trochanter 0.44/0.25 (1.76), femur 0.75/0.29 (2.59), patella 0.77/0.33 (2.33), chela (with pedicel) 1.33/0.47 (2.83), chela (without pedicel) 1.22 (2.60), hand (without pedicel) 0.69 (1.47), movable finger length 0.53 (0.77 times longer than hand without pedicel). LegI: femur 0.27/0.18 (1.50), patella 0.41/0.17 (2.41), tibia 0.44/0.12 (3.67), tarsus 0.39/0.08 (4.88). Leg IV: femur + patella 0.79/0.30 (2.63), tibia 0.61/0.16 (3.81), tarsus 0.42/0.11 (3.82).

Distribution. Known only from the type locality.

Habitat. All specimens were collected under the tree bark of Populus (Salicaceae), the specific species name unknown.