Stenohya xiningensis, Zhao, Yong-Wei, Zhang, Feng & Jia, Ying, 2011

Zhao, Yong-Wei, Zhang, Feng & Jia, Ying, 2011, Two new species of the genus Stenohya Beier, 1967 (Pseudoscorpiones, Neobisiidae) from China, Zootaxa 2834, pp. 57-64 : 61-63

Stenohya xiningensis sp. nov.

( Figs. 20–29 )

Type material. Holotype male (Ar.-MHBU-QH970603), China: Qinghai Province, Xining City, Laoye Mountain [36°55'N, 101°41'E], 3 June 1997, Min Wu leg.

Etymology. The specific name refers to the type locality.

Diagnosis. This new species resembles S. gruberi ( Ćurčiċ, 1983) , but can be distinguished from the latter by the proportions of the pedipalp segments. The teeth of the movable chelal finger of S. xiningensis sp. nov. differ from those of the other species for which the dentition has been described in being spaced apart.

Description. Male (holotype). Colour mostly brown, pedipalps and legs slightly lighter. Setae on the body long, straight and acicular.

Carapace ( Fig. 20 ). Smooth, 1.4 times longer than broad, lateral margins slightly convex; with a total of 24 setae, including 6 on anterior and 6 on posterior margin; pairs of lyrifissures near the eyes and posterior margin; epistome small, triangular; 4 eyes, anterior pair with lens, posterior pair represented by eyespots.

Abdomen ( Fig. 29 ). Pleural membrane strongly granulate. Anterior tergites with uniseriate setation, but posterior tergites with tactile setae situated slightly anterior to other setae; tergal chaetotaxy: 4: 8: 8: 8: 11: 11: 11: 11: 11: 11: 8, including at least 2 tactile setae on tergites VI–XI; sternal chaetotaxy (IV–XI): 29: 27: 34: 34: 32: 34: 16: 10, anal cone with 2 dorsal and 2 ventral setae; sternites V with 8, X with 2 and VI–IX with 12–16 medial discal setae, clearly longer than the marginal ones, colour around bases of discal setae lighter than rest of sternite. Anterior genital sternite with a group of 15 small setae in the middle; posterior genital sternite with 30 marginal setae, including 5 setae above each stigma, and 12 small setae in the middle. Genitalia not studied.

Pedipalps. Apex of coxa rounded and with 4 setae; laterally with 6 straight lyrifissures at margin; trochanter 1.20, femur 6.42, patella 4.68, chela (with pedicel) 4.46, chela (without pedicel) 3.86, hand (without pedicel) 1.69 times longer than broad, movable finger 1.59 times longer than hand (without pedicel). Venom apparatus present only in fixed chelal finger, venom duct very short. Anterior face of femur with several tubercles, but without granulation; patella and chelal hand smooth ( Fig. 21 ). Fixed chelal finger with 8 trichobothria, movable finger with 4 ( Fig. 28 ); eb and esb situated on base of the hand, grouped very closely with ib and isb; est, et and it grouped together at distal end of fixed finger; ist situated in terminal third, nearer to it than to isb. Trichobothria b and sb close to each other, situated in basal half, st and t close to each other in distal half of movable finger. Fixed chelal finger with 66 pointed teeth of unequal length, movable finger with about 47 teeth, which are pointed and of slightly unequal length in distal half, rounded and low in basal half and spaced ( Fig. 28 ).

Chelicera. Palm with 7 setae, movable finger with 1 sub-medial seta; fixed finger with 12 teeth; movable finger with 7 teeth ( Fig. 24 ); serrula exterior with 34 lamellae; serrula interior with 30 lamellae; galea elongated and divided into two main branches, each branch secondarily divided into 2–3 terminal branchlets ( Fig. 22 ); rallum of 8 blades, all with anteriorly-directed spinules, basalmost blade about half length of others, distalmost blade distinctly shorter than second and somewhat widened at its base ( Fig. 23 ).

Legs ( Figs. 25–27 ). Leg I: trochanter 1.24, femur 6.46, patella 3.71, tibia 6.10, metatarsus 4.22, telotarsus 5.25 times as long as deep; Leg IV: trochanter 2.82, femur + patella 5.42, tibia 8.31, metatarsus 5.20, telotarsus 7.11 times as long as deep. Tactile setae distributed as follows: tibia IV with 2 (TS 0.25 and 0.58), metatarsus IV with 3 (TS 0.14, 0.38 and 0.81), and telotarsus IV with 2 (TS 0.19 and 0.59); subterminal seta with two teeth in distal third ( Fig. 27 ); arolium not divided, shorter than slender and simple claws.

Dimensions (length/breadth or depth, in mm). Body length ca. 3.4. Carapace 1.10/0.79; diameter of anterior eye 0.10; diameter of posterior eye 0.09. Pedipalps: trochanter 0.53/0.44, femur 1.67/0.26, patella 1.45/0.31, chela (with pedicel) 2.32/0.52, chela (without pedicel) 2.16, hand length (without pedicel) 0.88, movable finger length 1.40. Chelicera 0.57/0.29, movable finger length 0.36. Leg I: trochanter 0.26/0.21, femur 0.84/0.13, patella 0.52/ 0.14, tibia 0.61/0.10, metatarsus 0.38/0.09, telotarsus 0.47/0.08. Leg IV: trochanter 0.54/0.19, femur + patella 1.41/ 0.26, tibia 1.08/0.13, metatarsus 0.52/0.10, telotarsus 0.64/0.09.

Remarks. Stenohya vietnamensis Beier, 1967 (type species) was described from a tritonymph without information on sexual characteristics or medial discal setae ( Beier, 1967; Harvey, 1991). Leclerc & Mahnert (1988) described pronounced sexual dimorphism in S. hamata , including: palp of male with a spine and a tubercle while that of female lacks the spine and is almost smooth; male with a cluster, but female with a pair of medial discal setae on the sternites VI–VIII. The new species S. curvata shows similar sexual dimorphism. S. caelata was described only from a female specimen, which has a pair of medial discal setae on the sternites VI–VIII; S. lindbergi was described from the tritonymph, which has a pair of medial discal setae on the sternites IV–X. Information is not available concerning medial discal setae in S. gruberi , S. martensi , S. kashimirensis and S. mahnerti . These fields of setae might be analogous to those seen in Withiidae and certain Garypinidae , but we have not been able to determine whether they are associated with glands.

Figures

FIGURES 20 – 27. Stenohya xiningensis sp. nov., male holotype. 20, carapace, dorsal view; 21, right pedipalp, dorsal view; 22, galea; 23, rallum; 24, right chelicera, dorsal view; 25, left leg IV; 26, tip of telotarsus IV; 27, subterminal seta of leg IV. Scale bars: 0.5 mm (20 – 21, 25); 0.05 mm (22, 23, 26); 0.1 mm (24); 0.25 mm (25).

FIGURES 28 – 29. Stenohya xiningensis sp. nov., male holotype. 28, right chelal fingers with trichobothriotaxy and teeth, mesal view; 29. abdomen, ventral view, showing sternites VI – VIII with 12 – 16 medial discal setae. Scale bar: 0.5 mm (28, 29).