Sinocanthium shuangqiu Yu & Li, 2020

Zhang, Jianshuang, Yu, Hao & Li, Shuqiang, 2020, New cheiracanthiid spiders from Xishuangbanna rainforest, southwestern China (Araneae, Cheiracanthiidae), ZooKeys 940, pp. 51-77 : 51

Sinocanthium shuangqiu Yu & Li sp. nov. Figure 11

Holotype.

♀ (IZCAS-Ar 34745, YHCH011), China, Yunnan Province, Xishuangbanna, Mengla County, Menglun Town, Xishuangbanna Tropical Botanical Garden, 48 km landmark in the reserve, seasonal rainforest; 21°58.704'N, 101°19.748'E, elevation ca. 1088 m, 12.VIII.2011, Guo Zheng leg.

Etymology.

The specific name is derived from the Chinese pinyin ‘shuāng qiú ', which means 'double ball’, and refers to the two bulb-shaped receptacles; noun in apposition.

Diagnosis.

The new species is easily distinguished from other cheiracanthiids by the epigyne, which has a fan-shaped fovea that is rebordered posteriorly and by the absence of copulatory ducts.

Description.

Female. Holotype (Fig. 11A, B ): TL 5.02; CL 2.13, CW 1.71, CI (CL/CW) 1.25; AL 2.89, AW 2.06. Carapace pale yellow, ocular area brown, a pair of brown lateral bands originating from behind PME and PLE, almost reaching posterior half of carapace. Eyes: AER almost straight, PER wider than AER and slightly procurved in dorsal view. All eyes dark, with black rings. Eye sizes and interdistances: OAL 0.51, OAW 0.93; AME 0.16, ALE 0.16, PME 0.17, PLE 0.13; AME-AME 0.21, AME-ALE 0.26, PME-PME 0.28, PME-PLE 0.34; MOQA 0.49, MOQP 0.58, CLL 0.11. Chelicerae with orange base, fangs red wine-coloured, both margins without teeth. Sternum yellowish, STL 1.17, STW 0.94. Labium and endites coloured as ocular area. Legs yellowish white, without any markings. Leg measurements: I and II missing, III - (-, 1.56, 1.36, 0.57), IV 8.02 (2.35, 2.59, 2.37, 0.71). Abdomen (Fig. 11A, B ) oval, dorsally yellowish white, dorsum with two pairs of inconspicuous muscle depressions; venter white with no distinct pattern.

Epigyne (Fig. 11C-G ). Atrium large and fan-shaped, located anteriorly on epigynal plate, margin delimited, atrial anterior margin long and indistinct, posterior margin heavily sclerotized; atrium ca. two times wider than long, blocked by mating plug before cleaning; receptacles clearly visible through the tegument in ventral view; copulatory openings small, located at basolateral atrial borders; receptacles perfectly round, separated by 0.8 diameters.

Male. Unknown.

Distribution.

Known only from the type locality, Xishuangbanna, Yunnan, China.

Figures

Figure 11. Sinocanthium shuangqiu sp. nov., female holotype. A habitus, dorsal view B habitus, ventral view C epigyne, intact, ventral view D epigyne, cleared, ventral view E vulva, cleared, dorsal view F epigyne, cleared and embedded in Arabic gum, ventral view G vulva, cleared and embedded in Arabic gum, dorsal view. Abbreviations: A = atrium; AAM = atrial anterior margin; APM = atrial posterior margin; CO = copulatory opening; FD = fertilization duct; R = receptacle. Scale bars: 1 mm (A, B); 0.2 mm (C-G).