Four species of spider genus Cheiracanthium C. L. Koch, 1839 (Araneae, Eutichuridae) from Jinggang Mountains, Jiangxi Province, China

Abstract Four species of spider genus Cheiracanthium C. L. Koch, 1839 are reported from Jinggang Mountains, Jiangxi Province, China. Two of them are described as new to science: C. auriculatum sp. n. (♀♂) and C. echinulatum sp. n. (♂). Cheiracanthium taiwanicum Chen, Huang, Chen & Wang, 2006 is recorded from Mainland China for the first time. Cheiracanthium zhejiangense Hu & Song, 1982, the most similar species to C. auriculatum sp. n., is a newly recorded species of Jiangxi Province. Detailed descriptions, diagnoses, and photographs of the two new species are given. Cheiracanthium taiwanicum and C. zhejiangense are also illustrated.


Introduction
Cheiracanthium C. L. Koch, 1839 contains 210 catalogued species and is mainly distributed in the Old World (Marusik and Fomichev 2016;World Spider Catalogue 2018). Although this genus is relatively large and well known, its taxonomy is rather poorly studied. Almost half of its species are known from single sex or juveniles: 36 by males, 60 by females, 2 by juveniles (World Spider Catalogue 2018). Additionally, 16 species were never illustrated and many species were described based on poor illustrations. So far, the genus has not been the subject of any global or regional revisions (Marusik and Fomichev, 2016).
The Cheiracanthium fauna of China is relatively rare and poorly represented, with only 38 described species (Li and Lin 2016;World Spider Catalogue 2018), of which 14 species are known based on a single sex: for 11, only females are known, and for three, only males are known (World Spider Catalogue 2018). Additionally, illustrations of the internal structure of the epigyne are not provided in five species (World Spider Catalogue 2018). Moreover, the diversity of this genus in China is still insufficiently known and several new species have been described in the last few years (Chen and Huang 2012; Barrion et al. 2013;Wang and Zhang 2013).
Field collection in Jinggang Mountains of Jiangxi province, China, was carried out in April 2011. During this field exploration, four Cheiracanthium species were found: C. auriculatum sp. n., C. echinulatum sp. n., C. taiwanicum Chen, Huang, Chen &Wang, 2006 andC. zhejiangense Hu &Song, 1982. Descriptions and photographs of the new species, as well as supplementary micrographs of the known species, are provided.

Materials and methods
Spiders were fixed and preserved in 80% ethanol. Specimens were examined with an Olympus SZX7 stereomicroscope; details were studied with an Olympus BX51 compound microscope. Male palps and female epigynes were examined and illustrated after being dissected. Epigynes were cleared in boiling KOH solution to dissolve soft tissues. Photographs were made with a Leica DFC450 digital camera mounted on an Olympus BX51 compound microscope. The digital images were taken and assembled using Helicon Focus 3.10 software package.
All measurements were obtained using an Olympus SZX7 stereomicroscope and given in millimetres. Eye diameters are taken at the widest point. The total body length does not include chelicerae or spinnerets length. Leg lengths are given as total length (femur, patella, tibia, metatarsus, tarsus TL total body length. Leg setae: v, ventral; p, prolateral; r, retrolateral. Most of the terminologies used in text and figure legends followed Lotz (2015), while a few others followed Marusik and Fomichev (2016) and Morano and Bonal (2016). 114°15'59.93"E), 26 April 2011, Hao Yu and Zhenyu Jin leg. Paratypes: 1♂ and 3 ♀, same data as holotype.
Etymology. The specific epithet is an adjective and is derived from a Latin word "auriculatus"(ear-like), referring to the tegular apophysis which is like the contour of an ear in ventral view.
Diagnosis. Cheiracanthium auriculatum sp. n. is distinguished from all other Cheiracanthium species, except C. zhejiangense Hu & Song, 1982 (Fig. 4A-E), by having a distally filiform cymbial spur in the male, and by the general shape of the vulva in the female. From C. zhejiangense, the male can be distinguished by the ear contour-shaped tegular apophysis and the uncoiling tip of cymbial spur (vs the falciform tegular apophysis and the coiled tip of the cymbial spur in C. zhejiangense) (Figs 1A-C; 4A-C), the female can be differentiated by the indistinct atrium and copulatory ducts (vs the distinct atrium and copulatory ducts in C. zhejiangense), the more or less lengthwise receptacles (vs the nearly horizontal receptacles in C. zhejiangense) (Figs 1D-E; 4D-E), and by the different coil number of copulatory ducts (7 coils in C. auriculatum sp. n., instead of 8 coils in C. zhejiangense) (Figs 1E; 4E). In addition, the two species can by separated by their habitus: abdomen without distinct colour pattern in C. auriculatum sp. n. (Fig. 1F-G), but with a median heart-shaped mark which reaches half of the opisthosoma length in C. zhejiangense (Fig. 4F-G).
Palp ( Fig. 1A-C). Tibia extremely long, about as long as cymbium, with two apophyses; retrolateral tibial apophysis (RTA) about 20% of tibia length, with a more or less bifurcate apex and hiding behind tegulum; prolateral tibial apophysis (PTA) small and round; cymbial spur (CS) is approximately equal in length to tibia, tapering off into a filiform; cymbial fold (CF) poorly developed, for approximately 4/5 the length of cymbium; tip of cymbium short, about 1/4 of cymbium length. Tegulum oblong, 1.3 times longer than wide; tegular apophysis (TA) long and sinuate, more than 4/5 of tegulum length, filamentous and like an ear's contour in ventral view; embolus (E) arising at approximately 10 o'clock position, terminating at approximately 11 o'clock position, it's tip covered by conductor (C); conductor large, falciform.
Epigyne (Fig. 1D-E). Atrium (A) indistinct, without delimited margin, about four times wider than long; receptacles (R) are faintly visible through epigynal plate in ventral view; two copulatory openings (CO) located at lateral borders of atrium; the transparent copulatory ducts (CD) running spirally (length of spira about 1.4 times longer than receptacles), forming 7 entwined loops (including 4 ascending coils and 3 descending coils); receptacle sickle-shaped, separated by three diameters.
Distribution. Presently known only from the type locality, Jinggang Mountains, Jiangxi, China (Fig. 5). Etymology. The species epithet is taken from the Latin adjective echinulatus and refers to the spinule-shaped tegular apophysis.
Palp ( Fig. 2A-C). Tibia twice shorter than cymbium, with three apophyses; retrolateral tibial apophysis (RTA) about 50% of tibia length, heavily sclerotised and with a fingerlike apex; prolateral tibial apophysis (PTA) distinctly elevated and relatively short, about 30% of tibia length, coniform in prolateral view and digitiform in ventral view; dorsal tibial apophysis (DTA) thin and stalk-shaped, about as long as RTA; cymbial spur (CS) beak-shaped, twice shorter than tibia; cymbial fold (CF) strongly developed and well visible in ventral and retrolateral view, for approximately 2/3 the length of cymbium; tip of cymbium long, about 1/3 of cymbium length. Tegulum 1.3 longer than wide, membranous and semitransparent except its margin in ventral view; tegular apophysis (TA) short and thin, spiculate; embolus (E) starts on the retrolateral flank (approximately 3 o'clock of tegulum), surrounds the base and ends at conductor (C) apex, its tip filiform and curved behind conductor; conductor large and membranous.
Distribution. Presently known only from the type locality, Jinggang Mountains, Jiangxi, China (Fig. 5). Description. Male and female (Fig. 4). Description of habitus, see Paik (1990). Since previous descriptions are rather brief, redescription of genitalia is provided as below.
Epigyne (Fig. 4D-E). Apron-like atrium distinct, about four times wider than long; receptacles are faintly visible through epigynal plate in ventral view; two copulatory openings located at lateral borders of atrium; the transparent copulatory ducts running spirally (length of spira about 2.6 times longer than receptacles), forming 8 entwined loops (including 4 ascending coils and 4 descending coils); receptacle long and tubular, separated by two diameters.