Parobisium motianense, Feng & Wynne & Zhang, 2020

Feng, Zegang, Wynne, J. Judson & Zhang, Feng, 2020, Cave-dwelling pseudoscorpions of China with descriptions of four new hypogean species of Parobisium (Pseudoscorpiones, Neobisiidae) from Guizhou Province, Subterranean Biology 34, pp. 61-98 : 61

Parobisium motianense sp. nov. Figs 2 , 3 , 4 , 5

Type material.

Holotype male (Ps.-MHBU- GZ17051801): China, Guizhou Province, Pingtang County, Tangbian Town, Motian Cave (Figs 1C , 18 ), [25°38'32.86"N, 104°46'00.36"E], 869 m elevation, 18 May 2017, Mingyi Tian leg. Paratypes: 2 males (Ps.-MHBU- GZ17051802 & GZ170501803), 1 female (Ps.-MHBU- GZ17051804), same data as for holotype.

Etymology.

Latinized adjective derived from the name of the type locality, Motian Cave.

Distribution.

This species is known only from the type locality.

Diagnosis.

Prior to this study, only four species of Parobisium have been reported in China ( Parobisium wangae Guo & Zhang, 2016, Parobisium xiaowutaicum Guo & Zhang, 2016, Parobisium magangensis Feng, Wynne & Zhang, 2019 and Parobisium yuantongi Feng, Wynne & Zhang, 2019). The new troglomorphic species can be distinguished from other members of the genus Parobisium by following combination of characters: carapace with four eye spots on a raised surface ( P. wangae has four developed eyes, P. tiani with two faint eye spots; P. magangensis , P. xiaowutaicum and P. yuantongi lacks eyes/eye spots); epistome small, rounded (small, triangular in P. wangae ; triangular, with rounded top in P. tiani and P. yuantongi ); carapace with six setae on posterior margin (eight in P. wangae ; eight in P. xiaowutaicum ); pedipalpal femur 4.66-4.90 times longer than wide (8.91-8.97 times in P. magangensis ; 3.89-4.11 times in P. qiangzhuang ; 6.50-6.59 times in P. sanlouense ; 5.63-5.73 times in P. tiani ; 3.60-3.65 times in P. wangae ; 6.75 times in P. yuantongi ); patella 3.09-3.39 times longer than wide (7.64-7.84 times in P. magangensis ; 2.54-2.60 times in P. qiangzhuang ; 5.07-5.11 times in P. sanlouense ; 4.52-4.58 times in P. tiani ; 1.89-2.16 times in P. wangae ; 5.70 times in P. yuantongi ;); pedipalpal hand which is finely granular (smooth in P. magangensis , P. wangae and P. xiaowutaicum ; with granulation present on inside lateral of femur and chelal hand in P. qiangzhuang and P. sanlouense ; with granulation present on femur, inside lateral of patella and chelal hand in P. yuantongi ); chela (with pedicel) 3.72-4.06 times longer than wide (8.67-8.69 times in P. magangensis ; 3.12-3.25 times in P. qiangzhuang ; 6.08-6.34 times in P. sanlouense ; 4.97-5.03 times in P. tiani ; 3.13-3.52 times in P. wangae ; 3.14 times in P. xiaowutaicum ; 5.70 times in P. yuantongi ); both chelal finger has 95-98 teeth (146-162 in P. magangensis ; 69-80 in P. qiangzhuang ; 119-130 in P. sanlouensis ; 57-74 in P. wangae ; 73-75 in P. xiaowutaicum ; 116-118 in P. yuantongi ).

Description.

Male (Fig. 3A ). Carapace, chelicerae, and pedipalps yellowish brown to reddish brown; abdomen and legs yellowish.

Carapace (Figs 4A , 5A ): Smooth, 1.16-1.20 times longer than broad, with a total of 28-30 setae, including 4 on anterior margin, 6 on posterior margin, and 1 on each side of anterior lateral margin; with four eye spots on a raised surface (Fig. 4B ); epistome small, rounded.

Chelicera (Figs 4C , 5B ): Hand with 7 setae, movable finger with 1 submedial seta; fixed finger with 12-14 teeth; movable finger with 14-15 teeth; serrula exterior with 40-44 lamellae; serrula interior with 25-29 lamellae. Galea (Fig. 5E ) replaced by a small rounded transparent sclerotic knob. Rallum (Fig. 5C ) with 8 pinnate blade, distal-most blade with expanded base, and together with the second blade slightly separated from the others, proximal one short.

Pedipalps (Figs 4D-E , 5H-J ): Apex of coxa rounded, with 5 setae on each side, pedipalpal coxa with 7 setae. Pedipalp smooth and slender except for hand, which is finely granular. Trochanter 2.04-2.22 times longer than wide, femur 4.66-4.90, patella 3.09-3.39 times longer than wide, pedicel about half the entire length of patella, chela (with pedicel) 3.72-4.06, chela (without pedicel) 3.35-3.71 times longer than wide, movable finger 1.43-1.45 times longer than hand (without pedicel). Fixed chelal finger with 8 trichobothria, movable finger with 4, eb and esb on lateral margin of hand; ib, ist, and isb closely grouped at the base of the fixed finger; est slightly distal of finger middle; it closer to fingertip than et; on movable finger, st nearer to t than to sb, the distance between sb and b is somewhat equal to that of sb and st (Figs 4D , 5H-I ). Venom apparatus present only in fixed chelal finger, venom duct short, not extending beyond half the distance to et. Fixed chelal finger with 96-98 teeth, movable finger with 95-97 teeth.

Abdomen: Pleural membrane granulated. Tergal chaetotaxy (I-XI): 8-11/9-10/9/9-11/10-11/10-11/9-12/11-12/11-12/10-11/6-8; sternal chaetotaxy (IV-XI): 9-10/14-16/15-16/15/13-16/12-14/12-15/2; stigmata with 5-6 setae; anal cone with 2 dorsal and 2 ventral setae. Male genital area (Figs 4F , 5F ): sternite II with 35-38 scattered setae; sternite III with anteromedian groove flanked by one small seta on each side, with 20-26 posterior setae.

Legs: Coxa chaetotaxy (I-IV): 8-9/6-7/3-4/9-10. Leg I (Figs 4H , 5K ): femur 4.37-4.96, patella 2.92-3.22, tibia 6.00-7.27, basitarsus 3.33-3.85, telotarsus 5.50-5.57 times longer than deep, femur 1.55-1.61 times longer than patella, telotarsus 1.54-1.56 times longer than basitarsus. Leg IV (Figs 4I , 5L ): femur + patella 4.36-5.00 times longer than deep, femur shorter than patella; tibia 8.04-9.05, basitarsus 3.81-3.88, telotarsus 5.44-6.36 times longer than deep, telotarsus 1.35-1.43 times longer than basitarsus; tibia with one tactile setae (TS=0.52-0.54), basitarsus with one tactile setae (TS=0.15-0.16), telotarsus with one tactile setae (TS=0.49-0.53); subterminal tarsal seta (Fig. 5D ) bifurcate; arolium not divided, shorter than the slender and simple claws.

Female (paratype; Fig. 3B ): Mostly same as holotype.

Chelicera. Hand with 7 setae, movable finger with 1 submedial seta; fixed finger with 15-17 teeth; movable finger with 14-15 teeth; serrula exterior with 41 lamellae; serrula interior with 23 lamellae. Galea replaced by a conspicuous semicircular transparent sclerotic knob; rallum of 8 blades, similar to holotype.

Pedipalps. Pedipalpal coxa with 8-9 setae. Trochanter 2.08, femur 4.52, patella 3.02, chela (with pedicel) 3.69, chela (without pedicel) 3.33 times longer than wide, movable finger 1.22 times longer than hand (without pedicel). Fixed chelal finger with 97 teeth, movable finger with 95 teeth.

Abdomen. Tergal chaetotaxy (I-XI): 8/7/9/10/10/11/11/11/11/10/6; sternal chaetotaxy (IV-XI): 11/16/17/16/16/14/12/2. Female genital area (Figs 4G , 5G ): sternite II with 6-7 setae on each side; sternite III with a row of 20 setae on the posterior margin.

Measurements: (length/breadth or depth in mm; ratios for most characters in parentheses). Male (holotype and paratypes). Body length 4.26-4.78. Carapace 1.16-1.20 (1.31-1.36/1.13). Pedipalpal trochanter 2.04-2.22 (0.91-0.96/0.41-0.47), femur 4.66-4.90 (1.96-2.05/0.40-0.44), patella 3.09-3.39 (1.66-1.73/0.49-0.56), chela (with pedicel) 3.72-4.06 (3.09-3.13/0.77-0.83), chela (without pedicel) 3.35-3.71 (2.78-2.86/0.77-0.83), hand length (without pedicel) 1.30-1.31, movable finger length 1.86-1.90 (1.43-1.45 times longer than hand without pedicel). Leg I: trochanter 1.36-1.50 (0.39/0.26-0.28), femur 4.37-4.96 (1.18-1.19/0.24-0.27), patella 2.92-3.22 (0.74-0.76/0.23-0.26), tibia 6.00-7.27 (1.02-1.09/0.15-0.17), basitarsus 3.33-3.85 (0.50/0.13-0.15), telotarsus 5.57-5.50 (0.77-0.78/0.14). Leg IV: trochanter 2.13-2.44 (0.64-0.67/0.27-0.30), femur + patella 4.36-5.00 (1.90-1.92/0.38-0.44), tibia 8.04-9.05 (1.85-1.90/0.21-0.23), basitarsus 3.81-3.88 (0.61-0.66/0.16-17), telotarsus 5.44-6.36 (0.87-0.89/0.14-0.16).

Female (paratype). Body length 5.99. Carapace 1.14 (1.46/1.28). Pedipalpal trochanter 2.08 (1.02/0.49), femur 4.52 (2.08/0.46), patella 3.02 (1.81/0.60), chela (with pedicel) 3.69 (3.28/0.89), chela (without pedicel) 3.33 (2.96/0.89), hand length (without pedicel) 1.47, movable finger length 1.79 (1.22 times longer than hand without pedicel). Leg I: trochanter 1.47 (0.44/0.30), femur 4.62 (1.20/0.26), patella 3.57 (0.82/0.23), tibia 6.76 (1.15/0.17), basitarsus 3.40 (0.51/0.15), telotarsus 5.13 (0.77/0.15). Leg IV: trochanter 2.28 (0.73/0.32), femur + patella 5.10 (1.99/0.39), tibia 8.58 (2.06/0.24), basitarsus 3.72 (0.67/0.18), telotarsus 5.29 (0.90/0.17).

Figures

Figure 1. Study area, general cave locations, and type locality for each species, Guizhou Province, China. A Biyun Cave, Parobisium tiani sp. nov. B Zharou Cave, Parobisium qiangzhuang sp. nov. C Motian Cave, Parobisium motianense sp. nov. D Sanlou Cave, Parobisium sanlouense sp. nov.

Figure 2. Parobisium motianense sp. nov. Sex indeterminable from photo.

Figure 3. Parobisium motianense sp. nov. A Holotype male, dorsal view B Paratype female, dorsal view.

Figure 4. Parobisium motianense sp. nov., holotype male (A - F, H - I), female (G). A Carapace, dorsal view B Eye area, lateral view C Left chelicera, dorsal view D Right chela, lateral view E Right pedipalp, dorsal view F Male genitalia G Female genitalia H Left leg I, lateral view I Left leg IV, lateral view.

Figure 5. Parobisium motianense sp. nov., holotype male (A - F, H - L), female (G). A Carapace, dorsal view B Left chelicera, dorsal view C Rallum D Subterminal tarsal seta E Movable finger of chelicera, showing sclerotic knob F Male genitalia G Female genitalia H Right chela, dorsal view I Right chelal fingers, lateral view J Right pedipalp, dorsal view (trochanter, femur, and patella) K Left leg I, lateral view L Left leg IV, lateral view. Scale bars: 0.1 mm (C, D - E), 0.25 mm (B, F - G), 0.5 mm (A, I), 1 mm (H, J - L).

Figure 18. Motian Cave, type locality of Parobisium motianense sp. nov. A Surrounding vegetation and agricultural areas with cave entrance (Red arrow) B Entrance C Inside the cave entrance D Stalactites E Cave landscape.