Paraceto spiralis, Zhang, Feng, 2017

Zhang, Feng, 2017, Description of Paraceto gen. n. and a relimitation of the genus Cetonana (Araneae: Trachelidae), Zootaxa 4320 (2), pp. 225-244 : 235-240

Paraceto spiralis sp. n.

Figs 6–9

Type material. Holotype: ♂, CHINA: Sichuan Province: Shimian County, Liziping National Nature Reserve, near the Zimaping Forest Management Station (28.985647°N, 102.278266°E), 1872m a.s.l., 27 July 2016, leg. Chi Jin and Xiangbo Guo ( MHBU) . Paratypes: 1♀ 12♂, same data as holotype ( MHBU) ; 3♂, same data as holotype but 28 July 2016 ( MHBU) .

Etymology. The specific name is derived from the Latin spiralis . It refers to the spiralling copulatory duct.

Diagnosis. The new species closely resembles P. orientalis comb. n. in having a similar coiled embolus, along with the elongate coiled cymbium, large patellar apophysis of the male palp and a similar internal duct system of the female vulva, but can be distinguished from it by: 1) the embolus coiled only once, whereas it is coiled twice in P. orientalis comb. n.; 2) the cymbium without a triangular apophysis at its base dorsally, while present in the latter species; 3) the epigynal plate as wide as long, whereas it is obviously wider than long in P. orientalis comb. n.; 4) the position of the copulatory openings is more anterior than that of the latter species; 5) the ST2 are pear-shaped, whereas they are oval in P. orientalis comb. n..

Description. Male. Total length 4.23–4.70 (n = 15). Holotype: body 4.70 long; carapace 2.15 long, 1.90 wide; abdomen 2.55 long, 1.94 wide ( Figs. 6A–B ). Body entirely covered with numerous long, slender pale grey hairs. Carapace dark brown, ovoid in dorsal view, convex, highest between fovea and PER, densely covered with tiny granulations ( Fig. 7A ). CRW 1.29, 0.68 times carapace width. Fovea black, distinct.

AER and PER slightly recurved in dorsal view ( Fig. 7F ). Eye diameters: AME 0.13, ALE 0.15, PME 0.14, PLE 0.14. Eye interdistances: AME–AME 0.11, AME–ALE 0.03, PME–PME 0.21, PME–PLE 0.15, ALE–PLE 0.10. MOA 0.30 long, anterior width 0.37, posterior width 0.47. PERW 0.90, 0.70 times CRW. Clypeus height 0.16, wider than diameter of AME. Chilum triangular, sclerotised and brown, with median indentation ( Fig. 7C ).

Chelicerae ( Fig. 7C ) dark brown, covered with granulations carrying hairs similar to carapace, cheliceral boss pronounced; with three promarginal and two retromarginal teeth. Endites ( Fig. 6B ) light yellow-brown, apex obtuse angle shape; labium brown, slightly wider than long. Sternum ( Fig. 6B ) yellow-brown, shield-shaped, with sharp precoxal triangles and blunt intercoxal sclerites.

Anterior legs ( Figs 8A–B ) yellow-brown and posterior legs ( Figs. 8E–F ) light yellow-brown; short, black ventral leg cusps present on tarsi and metatarsi I–II, arranged sparsely in two lines ( Figs 8C–D ). Measurements of legs: leg I 6.03 (1.84, 0.77, 1.56, 1.14, 0.72), II 5.87 (1.76, 0.73, 1.48, 1.18, 0.72), III 4.24 (1.24, 0.58, 0.89, 1.02, 0.51), IV 5.68 (1.62, 0.63, 1.37, 1.50, 0.56). Leg formula: 1243. Abdomen oval, yellowish pink, with several indistinct pale grey chevrons posteriorly and two pairs of sigilla medially; dorsal scutum absent ( Fig. 6A ). Venter yellowish-pink, with two narrow lines of sclerotized spots ( Fig. 6B ).

Palp as illustrated ( Figs 9A–E , 10A–C ). Femur with a small, shallow ventral terminal groove (VFG); patella with large blunt apophysis, pointed retrolaterally. Tibia with one large hook-shaped apophysis retrolaterally, with sharp tip pointed anteriorly. Tegulum pear-shaped, basally rounded, sperm duct invisible in dorsal view, with one apical and one prolaterally apophyses; subtegulum nearly invisible in dorsal view. Embolus well-developed, slender, originating prolaterally, coiled in large circle retrolaterally. Cymbium posteriorly expanded and anteriorly developed, anti-clockwise coiled to tapering tip (left palp in retrolateral view), with long cymbial furrow along with embolus.

Female ( Figs 6C–D ). Total length 4.40. Carapace 2.02 long, 1.79 wide; abdomen 2.38 long, 1.83 wide. CRW 1.13, 0.63 times carapace width. Eye diameters: AME 0.13, ALE 0.14, PME 0.14, PLE 0.14. Eye interdistances: AME–AME 0.11, AME–ALE 0.04, PME–PME 0.19, PME–PLE 0.16, ALE–PLE 0.11. MOA 0.32 long, anterior width 0.35, posterior width 0.41. PERW 0.83, 0.73 times CRW. Clypeus height 0.14, slightly wider than diameter of AME. Chilum visible in ante-ventral view ( Fig. 7E ). Leg measurements: I lost; II 5.36 (1.65, 0.73, 1.26, 1.03, 0.69); III 4.13 (1.25, 0.59, 0.83, 0.99, 0.47); IV 5.83 (1.65, 0.68, 1.39, 1.54, 0.57). Leg formula: -4-23. Legs without cusps ( Figs 8G–I ). Body colour much lighter than that of male, because it had recently moulted prior to being collected. Other characters as in male.

Epigyne ( Figs 9F , 10D ): epigynal plate as wide as long, weakly sclerotized; copulatory openings situated laterally, large and oval, posterior edge of copulatory openings substantially at same level as posterior edge of ST2; hood absent. Vulva ( Figs 9G , 10E–F ): copulatory ducts long, anteriorly thick and posteriorly slender, coiled three times before attached to ST2; ST2 large, pear-shaped, close to each other; connecting ducts slender, coiling around anterior part of copulatory ducts; ST1 spherical, connected to basally weakly sclerotized FD.

Distribution. Known only from the type locality ( Fig. 12 ).

Figures

FIGURE 6. Paraceto spirallus sp. n., A. male habitus, dorsal view; B. same, ventral view; C. female habitus, dorsal view; D. same, ventral view.

FIGURE 7. Paraceto spiralis sp. n., A. male habitus, lateral view; B. female habitus, lateral view; C. male cephalothorax, frontal view; D. female cephalothorax, frontal view; E. same, frontal-ventral view; F. male ocular area, dorsal view; G. female ocular area, dorsal view.

FIGURE 8. Paraceto spiralis sp. n., A. male left leg I, retrolateral view; B. male left leg II, retrolateral view; C. male left metatarsus and tarsus I, ventral view; D. male left metatarsus and tarsus II, ventral view; E. male left leg III, retrolateral view; F. male left leg IV, retrolateral view; G. female left metatarsus and tarsus I, retrolateral view; H. female left leg III, retrolateral view; I. female left leg IV, retrolateral view.

FIGURE 9. Paraceto spiralis sp. n., A. male left palp, prolateral view; B. same, ventral view; C. same, retrolateral view; D. same, dorsal view; E. male left palpal femur, ventral view; F. epigyne, ventral view; G. vulva, dorsal view.

FIGURE 10. Paraceto spiralis sp. n., A. male left palp, prolateral view; B. same, ventral view; C. same, retrolateral view; D. epigyne, ventral view; E. vulva, dorsal view; F. schematic of internal duct system.

FIGURE 12. Distribution of Paraceto gen. n. and Cetonana species of China.