Bisetocreagris juanxuae, Volker Mahnert & Yun-chun Li, 2016

Volker Mahnert & Yun-chun Li, 2016, Cave-inhabiting Neobisiidae (Arachnida: Pseudoscorpiones) from China, with description of four new species of Bisetocreagris Ćurčić, Revue suisse de Zoologie 123, pp. 259-268: 265-267

publication ID 10.5281/zenodo.155299

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scientific name

Bisetocreagris juanxuae

n. sp.

Bisetocreagris juanxuae   n. sp.

Figs 17-23 View Figs 11 - 23

Holotype: MSWU; ♀; China, Sichuan Province, Xing Wen, Shi Hai Town , Dao Cave , alt. 840 m, 28°18900’N 105°12118’E; 17 October 2015; coll. Yun-chun Li. This big cave is about 1000 m long and 50 m high; the pseudoscorpions were collected by hand under rocks, together with some spiders. GoogleMaps  

Paratype: 1♂ (in MHNG); same data as for holotype.

Diagnosis: Troglobiomorphic habitus; carapace with 2 indistinct anterior eyes possessing indistinct lenses, about 2 diameters from the anterior margin, with 10-12 setae on posterior margin; tergite I with 12-13 marginal setae, the following ones with 7-8 setae. Chelicera: teeth of movable finger on thickened lamella; rallum with 9-11 pinnate setae, anterior seta without or with an only slightly expanded base, two basal setae distinctly shorter. Pedipalp smooth, very slender, femur 8.6 times longer than broad (length 4.65), patella 9.1 times (length 4.99), club 3.1 times longer than pedicel, hand with pedicel 4.3 times, chela with pedicel 10.0 times longer than broad, finger 1.3 times longer than hand with pedicel.

Etymology: This species is dedicated to Mrs Juan Xu, the wife of the junior author.

Description of ♂ and ♀: Carapace and pedipalp reddish brown, chelicera darker, abdominal segments and legs yellowish. Carapace 1.1-1.2 times longer than broad, anterior margin with a small irregularly rounded median knob, two indistinct small eyes with indistinct lenses situated about two diameters from anterior margin, with 31 (♂: 7/ 7/7/10) and 35 (♀: 6/ 6/11/12) setae; tergite I with 12 (♂) or 13 (♀) setae, the following tergites with 7-8, the last ones with 9-10 setae, tergite XI with 2 tactile setae. Manducatory process rounded, with 5 marginal setae; pedipalpal coxa with 5-8 setae and two round lyrifissures (mediodistally and laterobasally), coxa I 9-11, II 8-9, III 5-6 (in apical third), IV 19 setae; genital operculum of ♂ with about 80 short and thickened setae, genital opening with 4 (or 5) simple setae on each side of entrance, median genital sac short and wrinkled, lateral sacs short, apically inflated; genital operculum of ♀ with 6/6 medial marginal setae, genitalia not studied; sternite III of ♂ with an anteromedian groove, flanked by one tiny seta on each side and with 19 marginal and 18 medial discal setae and 6/6 suprastigmal setae (♀: 18+ 2x 5); IV 16 + 2x 5 (♀: 19+ 2x 3); V-X (♂ ♀) with about 18-20 setae, without distinct submarginal setae; XI 4 (2 tactile setae). Anal cone with 2+2 simple setae. Pleural membrane granular.

Chelicera ( Fig. 17 View Figs 11 - 23 ): 6-7 long, fine setae on hand; fixed finger with 12-17 uniform, triangular teeth, movable finger with 14-17 small, triangular teeth, medial ones on thickened lamella, subgaleal seta not reaching fingertip; galea of holotype ( Fig. 18 View Figs 11 - 23 ) a short slender transparent rod on right chelicera, on left chelicera a low transparent tubercle; right chelicera of ♂ with a short galea, its single branch forked apically and carrying a short subapical branchlet; left chelicera with distal part of galea apparently broken; serrula exterior with about 42- 47 blades, serrula interior not counted. Rallum ( Fig. 19 View Figs 11 - 23 ) with 9-11 pinnate setae, the distal one without expanded base in ♀ (♂: base slightly expanded).

Pedipalp of holotype ( Figs 20-21 View Figs 11 - 23 ) (of ♂ paratype in parentheses): All segments smooth, trochanter with 3 tiny ventral tubercles (= bases of broken setae?), 2.9 times (3.2 times) longer than broad, femur distally enlarged, 8.6 (9.0) times, patella 9.1 (9.6) times longer than broad, club much longer than pedicel (3.05, ♂ 3.01 times), hand with pedicel 4.3 (4.8) times, chela with pedicel 10.0 (10.8) times, without pedicel 9.6 (10.3) longer than broad, finger 1.34 (1.25) times longer than hand with pedicel; fixed finger with 146-148 small cusped teeth, movable finger with 152 teeth, rounded in basal third of finger; a very short venom duct present in fixed finger. Twelve trichobothria (8+4), et-it at same level near finger tip, est indistinctly nearer to ist than to et, eb-esb on distal lateral side of hand, sb on movable finger distinctly nearer to b than to st.

Leg I of holotype (paratype ♂): Femur 6.7 (7.4) times, patella 5.0 (4.9) times, tibia 10.3 (12.6) times, basitarsus 5.2 (5.5) times, telotarsus 7.8 (7.7) times longer than deep, femur 1.65 (1.74) times longer than patella, telotarsus 1.29 (1.27) times longer than basitarsus.

Leg IV ( Figs 22-23 View Figs 11 - 23 ): Femur+patella 10.8 (10.6) times longer than deep, femur shorter than patella, tibia 14.4 (15.1) times, basitarsus 5.6 (5.3) times, telotarsus 6.9 (7.6) times longer than deep, tactile setae probably present (most setae lacking) on basitarsus (near middle of segment) and on telotarsus (TS 0.63/0.59); subterminal setae forked and dentate in distal half, claws smooth and slender, longer than arolia.

Measurements of holotype ♀ (♂ paratype in parentheses): Body length 5.3 (5.0); carapace 1.90/1.64 (1.68/1.52). Pedipalp: trochanter 1.65/0.57 (1.63/0.51), femur 4.65/0.54 (4.19/0.47), patella 4.99/0.55 (4.71/0.49), length of pedicel 1.23 (1.18), hand with pedicel 3.13/0.73 (3.03/0.64), length of pedicel 0.33 (0.30), of finger 4.21 (3.81), of chela with pedicel 7.31 (6.86). Leg I: femur 2.38/0.35 (2.28/0.31), patella 1.44/0.29 (1.31/0.27), tibia 2.35/0.23 (2.49/0.20), basitarsus 0.99/0.19 (0.94/0.17), telotarsus 1.28/0.17 (1.20/0.16). Leg IV: femur+patella 4.18/0.39 (3.88/0.37), length of femur 1.86 (1.75), tibia 4.09/0.28 (3.95/0.26), basitarsus 1.22/0.22 (1.16/0.22), telotarsus 1.53/0.22 (1.41/0.19).

Remarks: This particular species belongs to a group of species that is characterized by the very short pedicel of the pedipalpal patella (about one fourth of total patella length), by the chelal finger distinctly longer than the hand with pedicel, by very slender pedipalp with a considerable length (about 17-18 mm). The new species shares with B. titanium   n. comb. a similar size and a similar slenderness of its pedipalp, but both species can be easily distinguished by the short chelal fingers of B. titanium   n. comb., which are much shorter than the hand. Bisetocreagris junaxuae   n. sp. might be related to B. scaurum   n. comb., known only from one tritonymphe from the Da Hei Dhong Cave (Yunnan Province).




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