Sudesna circularis, Zhang, Zhi-Sheng & Li, Shuqiang, 2011

Zhang, Zhi-Sheng & Li, Shuqiang, 2011, On four new canopy spiders of Dictynidae (Araneae) from Xishuangbanna Rainforest, China, Zootaxa 3066, pp. 21-36 : 30-35

Sudesna circularis sp. nov.

Figs 8–10

Type material. Holotype: Male, CHINA: Yunnan Province, Mengla County, primary tropical seasonal rain forest, 21°54.725ʹ N, 101°11.431ʹ E, alt. 734± 15 m, 8 August 2007, G. Zheng leg. Paratypes: 1 male, 7 females, same data as for holotype; 1 female, Menglun Nature Reserve, from canopy of the secondary tropical montane evergreen broad-leaved forest, 21°54.767ʹ N, 101°11.431ʹ E, alt. 880± 17 m, 6 August 2007, G. Zheng leg.

Etymology. The specific name is derived from the Latin word ‘ circularis ’, meaning ‘circular’ or ‘round’ and refers to the looped copulatory ducts of the epigyne; adjective.

Diagnosis. The new species is similar to the type species, S. hedini ( Schenkel, 1936) ( Figs 7 A–H) in having a small, membraneous RTA, a slender and circular embolus, a helical end of conductor ( Figs 7 F–G, 8A–C, 9D–F), widely separated copulatory openings, short copulatory ducts and the presence of spermathecal heads ( Figs 7 D–E, 8D–E, 10F–G); males can be distinguished by the absence of a pectinate DTA ( Figs 8 B–C, 9E–F), the longer embolus ( Figs 8 A, 9D), the pointed apex of conductor ( Figs 8 A–C), females by the slender, looped copulatory ducts, and the spherical spermathecal heads.

Description. Male. Total length 1.65–1.89. Holotype ( Figs 7 A–C): total length 1.89. Prosoma 0.83 long, 0.70 wide; opisthosoma 1.10 long, 0.60 wide. Dorsal shield of prosoma dark yellow, with high cephalic area. Fovea obsolete. Cervical groove distinct, radial furrows indistinct. Eight eyes in 2 rows. Anterior eye row recurved and posterior eye row procurved in dorsal view. Eye sizes and interdistances: AME 0.049, ALE 0.085, PME 0.064, PLE 0.073; AME–AME 0.056, AME–ALE 0.019, PME–PME 0.053, PME–PLE 0.075, ALE–PLE 0.008. MOA 0.20 long, the front width 0.15, the back width 0.18. Clypeus height 0.061. Chelicerae stout, dark yellow, with yellow small lateral condyles and three promarginal, two retromarginal teeth. Gnathocoxae yellow, longer than wide. Labium dark yellow, as long as wide. Sternum dark yellow, with truncated anterior margin and blunt posterior margin. Legs yellowish, without spines. Each leg with two metatarsal trichobothria dorsally, apical one about twice as long as proximal. Dorsal tarsi with a single short trichobothrium mesally. Length of calamistrum about one half of metatarsus IV. Leg measurements: I 3.11 (0.96, 1.07, 0.62, 0.46), II 2.96 (0.92, 1.01, 0.59, 0.44), III 2.29 (0.73, 0.75, 0.47, 0.34), IV 2.49 (0.78, 0.85, 0.52, 0.34). Leg formula: 1243. Opisthosoma oval. Dorsum greyish, with some small white scale-like markings near the midline and dark grey laterally. Venter greyish, with some white scale-like markings laterally. Cribellum narrower than the distance ALS–ALS. ALS and PMS yellowish grey and PLS dark yellow, apical segment of PLS smaller than half of basal segment.

Male palp ( Figs 8 A–C, 9E–F) without patellar apophysis. Tibia with a small, triangular, semitransparent RTA apically. Embolus originating prolaterally, with broad base. Conductor long, apex twisted anticlockwise in 2 loops, hook-like. Tip of conductor situated close to base of tibia retrolaterally.

Female. Total length 1.60–2.00. One paratype ( Figs 10 A–E): total length 1.80. Prosoma 0.76 long, 0.66 wide; opisthosoma 1.10 long, 0.70 wide. Eye sizes and interdistances: AME 0.040, ALE 0.072, PME 0.044, PLE 0.057; AME–AME 0.042, AME–ALE 0.031, PME–PME 0.058, PME–PLE 0.069, ALE–PLE 0.017. MOA 0.16 long, the front width 0.12, the back width 0.16. Clypeus height 0.045. Leg measurements: I 2.87 (0.90, 1.00, 0.57, 0.40), II 2.77 (0.87, 0.96, 0.54, 0.40), III 2.32 (0.74, 0.78, 0.47, 0.33), IV 2.61 (0.83, 0.91, 0.53, 0.34). Leg formula: 1243.

Epigyne with widely separated copulatory openings, the latter with pronounced inner margins. Copulatory ducts relatively long and distinctly coiled. Spermathecae nearly ellipsoidal, converging anteriorly. Spermathecal heads spherical, situated close to spermathecae anterior-laterally. Fertilization ducts thin and long, extending from the anterior parts of spermathecae, curving and pointing laterally ( Figs 8 D–E, 10F–G).

Distribution. Known only from the rainforest canopy of Xishuangbanna, Yunnan Province, China.

Figures

FIGURE 7. Sudesna hedini (Schenkel, 1936) from Guizhou. A. Female habitus, dorsal view; B. Eyes and chelicerae, frontal view; C. Chelicerae, ventral view; D. Epigyne, ventral view; E. Vulva, dorsal view; F. Male left palp, ventral view; G. Same, retrolateral view; H. Same, dorsal view.

FIGURE 8. Sudesna circularis sp. nov., holotype male (A – C) and female paratype (D – E). A. Left palp, ventral view; B. Same, lateral view; C. Same, dorsal view; D. Epigyne, ventral view; E. Vulva, dorsal view. Abbreviations: Co = conductor; CD = copulatory duct; CO = copulatory opening; Em = embolus; FD = fertilization duct; RTA = retrolateral tibial apophysis; S = spermatheca; SH = spermathecal head.

FIGURE 9. Sudesna circularis sp. nov., holotype male. A. Habitus, dorsal view; B. Same, lateral view; C. Same, ventral view; D. Left palp, ventral view; E. Same, lateral view; F. Same, dorsal view.

FIGURE 10. Sudesna circularis sp. nov., female paratype. A. Habitus, dorsal view; B. Same, lateral view; C. Same, ventral view; D. Metatarsus IV, showing calamistrum, retrolateral view; E. Eyes and chelicerae, anterior view; F. Epigyne, ventral view; G. Vulva, dorsal view.