Bisetocreagris chuanensis, 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 : 260-261

Bisetocreagris chuanensis n. sp.

Figs 1-5

Holotype: MSWU; ♂; China, Guizhou Province, Xin Hua Town, Jin Sha , Chuan Cave , alt. 1387 m, 27°23.797’N 106°06.104’E; 30 April 2010, coll. Yu-Cheng Lin . This large cave has a length of 700 m and is 70 m high; the pseudoscorpion was collected by hand under rocks, together with some spiders.

Paratypes: 1♂ (in MCSNV), 1♀ (in MHNG); China, Guizhou Province, Qianxi, Hong Lin Village, Wang Tian Dong, alt. 1500 m, cave length 770 m, 27°06’59’’N, 105°53’37’’E; 13 November 2001; coll. L. Latello & G. Gozzo.

Diagnosis: Troglobiomorphic habitus; carapace with 2 small eyes with indistinct lenses, 8 setae on posterior margin; anterior tergites with 10-11 marginal setae; pedipalp smooth excepted for hand with finely granular dorsodistal part; pedipalp slender, femur 4.4-4.8 times (length 1.56-1.70), patella 3.1-3.5 times (length 1.39- 1.53), club of patella 1.16-1.34 times longer than pedicel and about half the length of entire patella, hand with pedicel 1.7-2.0 times (length 1.22-1.42), chela with pedicel 3.7-4.0 times (length 2.57-2.83) longer than broad, finger as long as or longer than hand with pedicel. Chelicera: rallum with 8-9 pinnate setae, distal one with an expanded base.

Etymology: Latinized adjective, derived from the name of the locus typicus, the Chuan cave.

Description of males (female in parentheses): Carapace in anterior half reddish or yellow, basal part lighter and with several unsclerotized areas; pedipalp and chelicera reddish to light brown; abdominal segments yellowish. Carapace smooth, with 2 (anterior) eyes with indistinct lenses, about 2 diameters from the anterior margin; anterior margin with a small rounded knob, without a distinct epistome; a shallow transversal furrow present; chaetotaxy: 6/8-9/6/7-8: 27-29 (6/6/4/7: 23). Tergites undivided, chaetotaxy: 10-11/10/9- 10/9- 11/11 /10/10-11/ 10/10/8 /6-8 (7/7/7/8/7/7/9/ 9/10/11 /9/7), X-XI with numerous pores. Anal cone 2+2. Manducatory process with 5 (4) marginal setae; pedipalpal coxa with 6-8 (4) setae, two round lyrifissures, coxa I 8-9 (5), II 6-8 (5-6), III 4-6 (3), IV 8-10 (6); genital operculum with 31 setae (posterior ones longer than anterior ones)(♀: 10 medial marginal and discal setae), genital opening with 4/4 simple interior setae, median genital sac undivided, apically enlarged, short (reaching anterior half of sternite IV); lateral genital sacs short, caudally bent and apically inflated. Sternite III with anteromedian groove flanked by one small seta on each side, with 18 long setae (7 medial discal setae)+ 5/6 (4) suprastigmal setae, IV-XI: 11+ 2x 5/17/15 /14/ 13/14/12 /4 (2 lateral tactile setae) (♀: 11+ 2x 4/16/ 14/13/12 / 12/10/8), VI-X with 2 submedial, submarginal setae. Pleural membrane granular.

Chelicera ( Fig. 1 ): Hand with 6-7 setae, fixed finger with 13-15 small, pointed teeth, movable finger with 12-14 pointed teeth (medial ones on a slightly thickened lamella), subgaleal seta short, not reaching finger tip; galea ( Fig. 2 a, b): one male with a transparent rounded spinneret, the other one with a rounded spinneret (left) and a short transparent stump (right), indicating the presence of a broken galea; female with a short galea with two tiny apical branchlets ( Fig. 2 b); serrula exterior 36-40, serrula interior 30-34 blades (distal one deeply forked). Rallum ( Fig. 3 ) with 8 (9) pinnate setae, distal one separated and with expanded base, proximal one short.

Pedipalp ( Figs 4, 5 ): Smooth excepted for dorsodistal part of hand with fine granulation; trochanter with a small rounded ventral hump, 2.3 (2.5) times, femur distally enlarged, 4.4-4.6 (4.8) times, patella 3.1 (3.5) times longer than broad, club 1.6-1.7 (2.0) times longer than broad and 1.16-1.24 (1.34) times longer than pedicel, hand with pedicel 1.7-2.0 (1.9) times, chela with pedicel 3.7-4.0 (4.0) times, without pedicel 3.4-3.7 (3.7) times longer than broad, finger as long as or 1.14-1.21 (♀♂ paratypes) times longer than hand with pedicel. Fixed finger with 104-109 (91) cusped teeth, row shorter than on movable finger, movable finger with 103-112 (85) teeth, about 20 distal ones with tiny cusps. Trichobothria ( Fig. 5 ): 12 (8+4) (♀: 8+3 on left finger: st absent), eb-esb on hand, ib-isb-ist grouped at fixed finger base, it distal of et, est distinctly nearer to et than to ist; sb on movable finger halfway between b and st; very short venom duct in fixed finger.

Leg I: Femur 4.1-4.4 (4.5) times, patella 3.1-3.4 (3.1) times, tibia 5.8-6.1 (6.65) times, basitarsus 2.9-3.0 (3.0) times, telotarsus 4.6-5.0 (4.8) times longer than deep, femur 1.5-1.6 (1.6) times longer than patella, telotarsus 1.5-1.7 (1.7) times longer than basitarsus.

Leg IV: Femur+patella 4.5-4.8 (5.1) times longer than deep, femur shorter than patella, tibia 7.7-7.9 (7.3) times, basitarsus 3.0-3.4 (3.2) times, telotarsus 5.1 (5.2) times longer than deep; tibia with one tactile seta in middle (TS=0.47-0.55), basitarsus with two tactile setae (basally, distally) (TS= 0.13, TS= 0.83-0.86), telotarsus with a tactile seta near middle (TS=0.46-0.47); subterminal seta forked and dentate, claws slender and smooth, arolia undivided and distinctly shorter than claws.

Measurements of holotype ♂ (of paratype ♂; ♀ in parentheses): Body length 4.43 (3.50; 3.45); carapace 1.24/1.12 (1.28/1.12; 1.12/0.96). Pedipalp: trochanter 0.92/0.39 (-; 0.89/0.34), femur 1.70/0.38 (1.61/0.35; 1.56/0.33), patella 1.53/0.50 (1.39/0.45; 1.44/0.41), length of pedicel 0.69 (0.64; 0.62), hand with pedicel 1.42/0.70 (1.22/0.72; 1.26/0.65), length of pedicel 0.25 (0.21; 0.21), length of finger 1.41 (1.49; 1.43), length of chela with pedicel 2.83 (2.69; 2.57). Leg I: femur 0.96/0.22 (0.94/0.23; 0.87/0.19), patella 0.59/0.19 (0.64/0.19; 0.55/0.18), tibia 0.87/0.15 (0.86/0.14); 0.78/0.12), basitarsus 0.38/0.13 (0.37/0.12; 0.35/0.12), telotarsus 0.58/0.13 (0.62/0.1; 0.58/0.12). Leg IV: femur+patella 1.59/0.35 (1.60/0.33; 1.48/0.29), length of femur 0.71 (0.70; 0.67), tibia 1.62/0.21 (1.48/0.19; 1.33/0.18), basitarsus 0.52/0.17 (0.51/0.15; 0.45/0.14), telotarsus 0.73/0.14 (0.73/0.14; 0.72/0.14).

Remarks: This new species is similar, in pedipalpal measurements and proportions, to B. martii n. comb. from the Guo Quan Dong Cave (Yunnan Province) and to B. lampra ( Chamberlin, 1931) from Gu Shan, Fukien Province. All three belong to a group of species in which the pedicel of the patella is about half the length of the patella. Compared to B. martii n. comb., the new species has only two tiny eyes (four distinct ones in B. martii n. comb.), smooth pedipalpal segments except for the chelal hand, and more numerous teeth on the pedipalpal fingers (fixed/movable finger: 109/122 vs 83/81 vs 81). Bisetocreagris chuanensis n. sp. differs from B. lampra by the presence of only two eyes on the carapace (vs four in B. lampra ), by the smooth pedipalpal femur and patella, by a more slender pedipalpal femur (4.4 times vs 3.56 times) and a more slender patella (3.1 times vs 2.3 times), and by a stouter chela with pedicel 4.0 times (vs 4.7 times) longer than broad. Furthermore, trichobothria et/it are distinctly distal to t in B. chuanensis n. sp., but on the same level of t in B. lampra , st is on the same level of est in the new species, but distinctly distal to est in B. lampra .

Figures

Figs 1 - 10. (1 - 5) Bisetocreagris chuanensis n. sp., holotype ♂. (1) Left chelicera. (2) “ spinneret ” (broken?) of ♂ (a) and of ♀ (b). (3) Rallum. (4 - 5) Pedipalp (vestitural setae of chela fingers omitted), trochanter to patella (4) and hand (5). (6 - 10) Bisetocreagris cavernarum n. sp., holotype ♂. (6) Left chelicera. (7) Galea of ♂ (a) and of ♀ (b). (8) Rallum. (9 - 10) Pedipalp (vestitural setae of chelal fingers omitted), trochanter to patella (9) and hand (10). Scales: 0.5 mm (4 - 5, 9 - 10); 0.2 mm (2 - 3, 7 - 8; 1; 6).