Ptocasius rectangulus, Yang & Peng, 2023

Yang, Su-Fang & Peng, Xian-Jin, 2023, A review of the Ptocasius Simon, 1885 spiders of Gaoligong Mountains, China (Araneae: Salticidae), European Journal of Taxonomy 903 (1), pp. 1-61 : 39-41

Ptocasius rectangulus sp. nov.

urn:lsid:zoobank.org:act:874EBEAA-5E73-44EF-9993-671E5E56561D

Figs 27–28 , 46

Diagnosis

The new species resembles P. geminus sp. nov. ( Figs 16–17 ), but can be distinguished by: (1) posterior margin of pockets almost as long as wide in ventral view ( Figs 27B , 28A ), while two times as wide as long in P. geminus ( Figs 16B , 17D ); (2) top of pockets almost above posterior margin of copulatory openings in ventral view ( Figs 27B , 28A ), while below posterior margin of copulatory openings in P. geminus ( Figs 16B , 17D ); (3) copulatory openings almost rectangular in ventral view ( Figs 27B , 28A ), while almost arc-shaped in P. geminus ( Figs 16B , 17D ); (4) spermathecae distinctly diverging in dorsal view ( Figs 27C , 28B ), while almost touching in P. geminus ( Figs 16C , 17E ).

Etymology

The specific name is derived from the combination of the Latin adjective ‘ rectus ’ (‘straight’) and the Latin noun ‘ angulus ’ (‘angle’), referring to the atrium outline somewhat rectangular.

Type material

Holotype

CHINA • ♀; Yunnan Province, Nujiang Prefecture, Gongshan County, Nujiang State Nature Reserve , Qiqi , 9.9 km West of Gongshan; 27°42′55″ N, 98°33′55″ E; 2000 m a.s.l.; 9–14 Jul. 2000; Heng-mei Yan, David Kavanaugh, Charles Griswold, Hong-bin Liang, Darrell Ubick and Da-zhi Dong leg.; HNU-00–QF–6.

Description

Female (holotype)

BODY AND HEAD. Total length 4.90. Prosoma 2.20 long, 1.70 wide. Opisthosoma 2.70 long, 1.85 wide. Clypeus height 0.13. Carapace ( Fig. 27A ) light brown; carapace margin grayish black and eyes base black; ocular area dark brown. Fovea reddish brown. Radial groove dark brown. Eye diameter and interdistances: AME 0.50, ALE 0.28, PLE 0.28, AERW 1.60, PERW 1.55, EL 1.10. Sternum scutiform, the median area slightly bulged; light yellowish brown, margin dark; sides with three grayish black spots, covered with long brownish black hairs. Sternum brown, scattered with few black spots, sparsely covered with long light brown and dark brown hairs. Endites and labium dark brown, distal area yellowish brown, covered with grayish black hairs, labium triangular.

CHELICERAE ( Fig. 28C ). Brown, front side dark brown, distal area covered with grayish black hairs, two big promarginal teeth and one small retromarginal denticle.

LEGS. Yellowish brown, with black markings or annuli, densely covered with short black hairs; spines weak and short. Tibiae I and II with three pairs of long ventral spines, metatarsi I and II with two pairs of long ventral spines.

LEG MEASUREMENTS. I = 3.70 (1.20, 1.60, 0.50, 0.60), II = 3.60 (1.20, 1.40, 0.50, 0.50), III = 4.55 (1.45, 1.50, 0.90, 0.70), IV = 4.80 (1.50, 1.60, 1.00, 0.70). Leg formula: IV–III–I–II.

ABDOMEN ( Fig. 27A ). Oval, dorsum brown with irregular dark brown spots, densely covered with short dark brown hairs; ventral light gray with irregular black spots. Spinnerets dark brown.

EPIGYNUM ( Figs 27B–C , 28A–B ).As long as wide; the pockets close to each other, the top of pockets almost above posterior margin of copulatory openings in ventral view; copulatory openings almost rectangular.

Male

Unknown.

Distribution

China (Yunnan Province, Fig. 46 ).

Figures

Fig. 27. Ptocasius rectangulus sp. nov., holotype, ♀ (HNU-00–QF–6). A. Body, dorsal view. B. Epigynum, ventral view. C. Vulva, dorsal view. Scale bars: A = 0.5 mm; B–C = 0.1 mm.

Fig. 28. Ptocasius rectangulus sp. nov., holotype, ♀ (HNU-00–QF–6). A. Epigynum, ventral view. B. Vulva, dorsal view. C. Chelicerae, posterior view. Scale bars = 0.1 mm.

Fig. 46.Distribution records of the species: P. longlingensissp. nov. (▲), P. montanus (Żabka, 1981) (•) and P. rectangulus sp. nov. (▇).

Fig. 16.Ptocasius geminussp. nov.,paratype, ♀(HNU-00–GDS–2P). A. Body, dorsal view.B. Epigynum, ventral view. C. Vulva, dorsal view. Scale bars: A = 0.5 mm; B–C = 0.1 mm.

Fig. 17. Ptocasius geminus sp. nov. A–C. Holotype, ♂ (HNU-00–GDS–2A). D–E. Paratype, ♀ (HNU-00–GDS–2P). A. Palp, ventral view. B. Palp, retrolateral view. C. Chelicerae, posterior view. D. Epigynum, ventral view. E. Vulva, dorsal view. Scale bars = 0.1 mm.