Atemnus limuensis, Hu & Zhang, 2012

Hu, Jun-fang & Zhang, Feng, 2012, Notes on two species of the genus Atemnus Canestrini (Pseudoscorpiones: Atemnidae) from China, Journal of Threatened Taxa 4 (11), pp. 3059-3066 : 3062-3065

Atemnus limuensis sp. nov.

( Image 2 , Fig. 2 )

Type material: 07.v.2011, holotype male (Ps. - MHBU-HN11050701 ) from China, Hainan Province, Mt. Limu (19.170 N & 109.740 E), together with five males ( Ps. - MHBU-HN11050702– 11050706 ) , nine females ( Ps. - MHBU-HN11050707– 11050716 ) paratypes, coll. Junfang Hu leg.

Etymology: The specific name is derived from the type locality.

Diagnosis: This new species can be recognized by the following combination of characters: carapace with two distinct eyespots; body in large size (male 4.38– 4.88, female 5.40–6.25); retrolateral face of pedipalpal trochanter, prolateral face of pedipalpal femur and patella, and basal fingers distinctly granulate; dorsal and retrolateral face of trochanter with coniform tubercles; carapace covered with numerous setae.

Description: Pedipalps and the anterior half of carapace reddish-brown ( Image 2 ), tergites brown. Setae on body and legs apically dentate.

Carapace smooth, without furrow, longer than broad (1.16–1.20 × in male and 1.20–1.32 × in female); with distinct eyespots ( Fig. 2A ); 68–72 setae, with four on anterior margin and 8–10 on posterior margin; the anterior half darker than the posterior half.

Abdomen all tergites incompletely divided, halftergites with 4–9 marginal setae. Tergal chaetotaxy: 8–11: 8–11: 9–11: 12–16: 14–18: 16–17: 16–17: 16–17: 16–17: 14–17 (4T): 11–13 (4T): 2; sternites divided, half-sternites with 6–10 setae, sternal chaetotaxy (IV – XI): 16–17: 18–19: 17–18: 17–18: 18–20: 16–19: 12–18 (4T): 13 (4T): 2. Anterior genital operculum of male ( Fig. 2G ) with 8–9 setae on each side and 10–11 on posterior margin; that of female ( Fig. 2J ) with 8–10 setae on anterior genital operculum and 8–10 setae on posterior margin. Male genital structure ( Fig. 2K ): the hooked branch (b) bowed distally, terminated in a relatively small platelike tip, with a distinct dark sclerotized bar proximally (c); the longitudinal folder of medial diverticula (d) with a projection medially and a prominent extension along the sagittal plane, forming M-shape bulge (k); the ejaculatory canal atrium (e) crescent-shaped on both sides and the distal end of the atrium procurved; the lateral rods (f) long and diverging proximally; the tip of dorsal apodeme (g) completely joined; the ventral diverticulum (h) bilobed. Female genital structure ( Fig. 2I ) simple, spermathecae with separated median cribriform plate.

Cheliceral hand with four setae ( Fig. 2B ), bs and es short and finely dentated, is and ls long and acute, fixed finger with four retrorse teeth and 2–3 small apical teeth, movable finger with a long, tooth-like subapical lobe, male galea ( Fig. 2C ) relatively short, with 6–7 branchelets, female galea ( Fig. 2D ) long, with 5–6 distinct branchelets, of which the basal one rebranched, serrula exterior 27–28 lamellae, rallum ( Fig. 2E ) of 4 setae, only the distal one dentated anteriorly.

Pedipalp: trochanter 1.10–1.30, femur 2.22–2.55, patella 2.12–2.18, chela with pedicel 2.97–3.10, chela without pedicel 2.73–2.84, hand without pedicel 1.71– 1.72 longer than broad, and movable finger 0.59–0.63 × longer than hand (female trochanter 1.43–1.50, femur 2.27–2.38, patella 1.92–2.02, chela with pedicel 2.77– 2.92, chela without pedicel 2.49–2.58, hand without pedicel 1.58–1.67 longer than broad, and movable finger 0.63 × longer than hand). The retrolateral face of pedipalpal trochanter ( Fig. 2L ), prolateral face of pedipalpal femur and patella, and the basal fingers strongly granulated; trochanter with distinct coniform and granulated protuberances, fixed finger ( Fig. 2H ) with 29–30 cusped marginal teeth, movable finger with 35–36 marginal teeth, venom duct short, ramosus nodus medially between trichobothria et and it. Trichobothrial pattern: st on movable finger between t than sb; on fixed finger est at the level of ist, distance of est and esb same as ist and isb, it from finger tip nearly equals to distance between ist and isb.

Legs fairly stout and smooth, claws simple, longer than arolia, subterminal seta acute and curved. Tactile seta on tarsus IV ( Fig. 2F ) situated proximally (TS = 0.20).

Dimensions (length/breadth or depth, in mm): Male: Body length: 4.38–4.88. Carapace 1.10–1.20 / 0.95–1.00 (1.16–1.20); pedipalp: trochanter 0.50–0.65 / 0.45–0.50 (1.10–1.30), femur 1.00–1.20 / 0.45–0.47 (2.22–2.55), patella 1.10–1.20 / 0.52–0.55 (2.12–2.18), chela with pedicel 1.80–1.90 / 0.58–0.64 (2.97–3.10), chela without pedicel 1.65–1.75 (2.73–2.84), hand without pedicel 1.00–1.10 (1.71–1.72), movable finger length 0.63–0.65 (0.59–0.63 × hand); leg I: femur 0.33–0.35 / 0.25–0.27 (1.30–1.32), patella 0.58–0.60 / 0.23–0.25 (2.40–2.52), tibia 0.50–0.55 / 0.15–0.17 (3.24–3.33), tarsus 0.38 – 0.45 / 0.12–0.14 (3.17– 3.21); leg IV: femur + patella 1.05–1.15 / 0.38–0.40 (2.76–2.88), tibia 0.75–0.80 / 0.22–0.25 (3.20–3.41), tarsus 0.50 – 0.55 / 0.14–0.15 (3.57–3.67).

Female: Body length: 5.40–6.20. Carapace 1.20– 1.25 / 0.95–1.00 (1.25–1.26); pedipalp: trochanter 0.50–0.60 / 0.35–0.40 (1.43–1.50), femur 0.95–1.00 / 0.40–0.44 (2.27–2.38), patella 0.95–1.00 / 0.47–0.52 (1.92–2.02), chela with pedicel 1.75–1.80 / 0.60–0.65 (2.77–2.92), chela without pedicel 1.55–1.62 (2.49– 2.58), hand without pedicel 1.00–1.03 (1.58–1.67), movable finger length 0.63–0.65 (0.63 × hand); leg I: femur 0.30–0.32 / 0.25–0.26 (1.20–1.23), patella 0.55–0.57 / 0.23–0.25 (2.28–2.39), tibia 0.50–0.55 / 0.15–0.18 (3.06–3.33), tarsus 0.42–0.45 / 0.10–0.12 (3.75–4.20); leg IV: femur + patella 1.05–1.10 / 0.40– 0.45 (2.44–2.63), tibia 0.65–0.70 / 0.21–0.25 (2.80– 3.10), tarsus 0.50–0.55 / 0.13–0.15 (3.67–3.85).

Distribution: China (Hainan Island).

Habitat: Atemnus limuensis sp. nov. was collected from under an Ormosia tree bark in a humid tropical forest.

Remarks: Atemnus limuensis sp. nov. differs from A.letourneuxi in its large size and the presence of strong granules on the prolateral face of the chelal patella. Atemnus neotropicus from Puerto Rico is known only from a female, which differs from females of A. limuensis sp. nov. in having a small size (body length 4.10mm), light in color, the presence of weak eyespots and rounded dorsal protuberances on the chelal trochanter. Atemnus strinatii can be distinguished from A. limuensis sp. nov. in having round dorsal tubercles on the chelal trochanter, without eyespots and with weakly granulate chelal femur and patella. Atemnus limuensis sp. nov. differs from A. syriacus by the slender pedipalp (male femur 2.22–2.55 ×, patella 2.12–2.18 ×, chela with pedicel 2.97–3.10 ×, chela without pedicel 2.73–2.84 ×, hand without pedicel 1.71–1.72 × versus femur 2.1 ×, patella 1.7 ×, chela with pedicel 2.6 ×, chela without pedicel 2.3 × as long as broad in A. syriacus ) and the absence of a brown band on carapace.

Atemnus politus can be easily be separated from A. limuensis sp. nov. by the slimmer male genital organ ( Figs. 1K , 2K ): the ejaculatory canal atrium (e) is not well-developed and may be aberrant in A. politus ; but in A. limuensis sp. nov., the atrium is normal, crescent-shaped on either side, and the distal end of the atrium is typically procurved. Moreover, the distal part (l) of lateral apodemes (a) in A. limuensis sp. nov. is larger than that in A. politus . However, they have many congeneric characters in the male genitalia (the letters refer to those of Figs. 1K and 2K ): (1) the sclerotized distal part of lateral apodemes; (2) the presence of a hooked branch on proximal part of the lateral apodemes; (3) the presence of a rugose darker area on proximal part of the lateral apodemes; (4) the presence of a round projection on medial diverticulum and a prominent extension along the sagittal plane in M-shaped bulge (k) on two medial diverticula; (5) the long and proximally diverging lateral rods; (6) the distally joined long dorsal apodeme; and (7) the presence of bilobed anterior wall on the ventral diverticulum.

Figures

Figure 1. Atemnus politus. A - Male carapace, dorsal view; B - Male galea; C - Female galea; D - Spermatheca; E - Male pedipalp (minus chela), dorsal view; F - Male chela, lateral view; G - Male chelal fingers, lateral view; H - Female genital area; I - Leg IV; J - Male genital area; K - Male genital organ. Scale lines: 1.0mm (Figs. E–F), 0.5mm (Figs. A, I), 0.4 mm (Figs. D, G–H, J–K), 0.05mm (Figs. B–C).

Image 2. Atemnus limuensis sp. nov.: male habitus, dorsal view.

Figure 2. Atemnus limuensis sp. nov. A - Male carapace, dorsal view; B - Male chelicera, dorsal view; C - Male galea; D - Female galea; E - Rallum; F - Leg IV; G - Male genital area; H - Male chelal fingers, lateral view; I - Spermatheca; J - Female genital area; K - Male genital organ; L - Male pedipalp, dorsal view. Scale lines: 1.0mm (Figs. F, L), 0.5mm (Fig. A), 0.4mm (Figs. B, G–K), 0.05mm (Figs. C–E).