New cheiracanthiid spiders from Xishuangbanna rainforest, southwestern China (Araneae, Cheiracanthiidae) Author Zhang, Jianshuang School of Life Sciences, Guizhou Normal University, Guiyang, Guizhou, China Author Yu, Hao School of Biological Sciences, Guizhou Education University, Guiyang, Guizhou, China insect1986@126.com Author Li, Shuqiang Institute of Zoology, Chinese Academy of Sciences, Beijing, China https://orcid.org/0000-0002-3290-5416 lisq@ioz.ac.cn text ZooKeys 2020 940 51 77 http://dx.doi.org/10.3897/zookeys.940.51802 journal article http://dx.doi.org/10.3897/zookeys.940.51802 1313-2970-940-51 A6681E10846243D2A050FA5400F26682 B23B7E76A46F5307AA1E974588CA04C9 Cheiracanthium gou Yu & Li sp. nov. Figures 5 , 7C , 8C , 9C , 10G-I Holotype. ♂ (IZCAS-Ar 34746, YHCH016), 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 'gōu' , which means 'hook' , and refers to the curved distal tip of the cymbial spur which is shaped like a hook; noun in apposition. Diagnosis. Males of this new species can be easily distinguished from all other Cheiracanthium species by the structure of the palp. The retrolateral tibial apophysis consists of a thin distal half and a wide basal half. The cymbial spur is partly membranous proximally and sclerotized distally with the distal tip blunt and thick, hook-shaped (Figs 5A-C , 7C , 8C , 9C ). By contrast, in almost all known Cheiracanthium species, the retrolateral tibial apophysis and the cymbial spur cannot be easily divided into two parts, and the distal tip of the cymbial spur is usually sharply pointed, such as in C. daofeng sp. nov. and C. duanbi sp. nov. (Figs 1A-C , 3A-C , 7A, B , 8A, B , 9A, B ). Figure 5. Cheiracanthium gou sp. nov., male holotype. A Flipped right palp, prolateral view B left palp, ventral view C left palp, retrolateral view D habitus, dorsal view E habitus, ventral view F habitus, lateral view. Abbreviations: C = conductor; CS = cymbial spur; DTA = dorsal tibial apophysis; E = embolus; EB = embolic base; MA = median apophysis; RTA = retrolateral tibial apophysis. Scale bars: 0.2 mm ( A-C ); 1 mm ( D-F ). Description. Male. Holotype (Fig. 6D-F ): TL -; CL 3.63, CW 2.83, CI (CL/CW) 1.28; AL -, AW -. Carapace pale yellow, uniformly coloured, without distinct pattern; cephalic region inconspicuously raised, cervical groove and radial grooves distinct, tegument smooth, clothed with short, fine hairs. Eyes: in dorsal view, both anterior and posterior eye rows recurved, PER slightly wider than AER. All eyes dark, on tubercles. Eye sizes and interdistances: OAL 0.49, OAW 1.32; AME 0.22, ALE 0.20, PME 0.17, PLE 0.18; AME-AME 0.17, AME-ALE 0.18, PME-PME 0.22, PME-PLE 0.28; MOQA 0.53, MOQP 0.58, CLL 0.09. Chelicerae with three teeth on promargin and three on retromargin, with long red fangs. Sternum pale yellow, STL 1.67, STW 1.32. Labium and endites orange. Legs distinctly long, yellowish white, with brown metatarsi and tarsi, without distinct markings. Leg measurements: I 32.75 (8.38, 1.062, 11.29, 2.46), II - (5.32, -, -, -), III missing, IV 22.07 (6.4, 6.34, 7.72, 1.61); LL/CL 9.02. Abdomen missing. Palp (Figs 5A-C , 7C , 8C , 9C , 10G-I ). Tibia with two apophyses: long and sclerotized retrolateral apophysis, ca. 1/3 of palpal tibia length, with thin distal half and wide basal half; and a short, thin, stalk-like dorsal apophysis; cymbial spur short, ca. 1/3 of cymbium length, partly membranous proximally, heavily sclerotized distally, distal tip curved and blunt; cymbial fold poorly developed and indistinct in ventral and retrolateral views for ca. 1/2 the length of cymbium; tip of cymbium long, ca. 1/2 of cymbium length. Bulb elongated, 1.5 times longer than wide; median apophysis long and hyaline, more than 1/2 of tegulum length, with wide base, thin middle part, and hook-shaped tip; embolus originates at ca. 1 o'clock position, surrounds base, and ends atop conductor at distal end of tegulum; conductor short, thick, membranous. Female. Unknown. Comments. According to the WSC (2020) , a total of ten Cheiracanthium species from China are known only from females: C. approximatum O. P.-Cambridge, 1885, C. escaladae Barrion et al., 2013, C. fujianense Gong, 1983, C. hypocyrtum Zhang & Zhu, 1993, C. liuyangense Xie et al., 1996, C. olliforme Zhang & Zhu, 1993, C. potanini Schenkel, 1963, C. solidum Zhang et al., 1993, C. sphaericum Zhang et al., 1993, and C. longtailen Xu, 1993. Among them, C. escaladae is supposedly a Clubiona species based on epigyne morphology, C. approximatum and C. potanini are doubtful or invalid species because of the poor original illustrations and descriptions, C. liuyangense may be a synonym of C. taegense Paik, 1990, and C. longtailen is considered a junior synonym of C. pichoni Schenkel, 1963. The remaining five species can be tentatively considered valid species. In addition, C. spectabile (Thorell, 1887) from Myanmar is known by the male but is not illustrated. We cannot rule out the possibility that the above six species are conspecific to C. gou sp. nov. Distribution. Known only from the type locality, Xishuangbanna, Yunnan, China.