Four new species of the primitively segmented spider genus Qiongthela from Hainan island, China (Mesothelae, Liphistiidae)

Abstract Four species of the primitively segmented spider genus Qiongthela Xu & Kuntner, 2015 collected from Hainan Island, China are diagnosed and described as new to science based on their genital morphology: Q. bawang sp. n. (♀), Q. jianfeng sp. n. (♂♀), Q. yini sp. n. (♀), Q. wuzhi sp. n. (♂♀). Together with the type species of Qiongthela, Q. baishensis Xu, 2015, five species are found and described from Hainan, China, and seven species are now known in the genus.


Introduction
The primitively segmented spider family Liphistiidae (Araneae, Mesothelae), an ancient lineage that retains plesiomorphic arachnid traits such as the abdominal tergites and spinnerets located in the middle of abdominal venter, currently contains 101 species in eight genera (World Spider Catalog 2017;Xu et al. 2015a, b). These extant species are restricted to Southeast and East Asia and display an extremely high level of endemism and disjunct distribution (Xu et al. 2015a(Xu et al. , b, 2016. They are divided into two subfamilies, Heptathelinae and Liphistiinae (Xu et al. 2015a, b). While the subfamily Liphistiinae contains a single genus (Liphistius Schiödte, 1849) with species in Southeast Asia (Sumatra, Laos, Malaysia, Myanmar, Thailand), Heptathelinae has seven genera. Two of them (Heptathela Kishida, 1923 andRyuthela Haupt, 1983) are confined to Japan (Ryukus islands and Kyushu), and the other five are distributed between mainland China and Vietnam: Ganthela Xu & Kuntner, 2015, Qiongthela Xu & Kuntner, 2015, Sinothela Haupt, 2003, Songthela Ono, 2000and Vinathela Ono, 2000 (World Spider Catalog 2017; Xu et al. 2015a, b). Since the genus level revision of the family (Xu et al. 2015a, b), species-level revisions have been proposed for two genera, Ganthela (Xu et al. 2015c) and Ryuthela (Xu et al. 2017).
In this study, we focus on the genus Qiongthela from Hainan Island, China, located in the transitional zone between tropical and temperate zones in the South China sea. Qiongthela was diagnosed in 2015 (Xu et al. 2015a, b), but so far, only three Qiongthela species have been named: Q. baishensis Xu, 2015, the type species from Hainan, and Q. australis (Ono, 2002) and Q. nui (Schwendinger & Ono, 2011) from southern Vietnam (Xu et al. 2015b). Even though no molecular data were available for the two Vietnamese species of Qiongthela in our previous studies (Xu et al. 2015a), the genital morphology confirms their inclusion in Qiongthela (Ono 2002;Schwendinger and Ono 2011;Xu et al. 2015b). Here, four new species of Qiongthela collected from Hainan are diagnosed and described. Their taxonomy is based on male and female genital morphology combined with the results from prior phylogenetic analyses, which support the four new species ( fig. 2 in Xu et al. 2015a).

Materials and methods
All Qiongthela specimens in this study were collected at the roadside of forest (Figs 1A, 2A, 4A). They were collected alive and fixed in absolute alcohol if they were adults. The subadults were brought back to the laboratory and reared until they reached maturation. All specimens were then preserved in 80% ethanol after the right four legs were removed for molecular work.
Specimens were studied using an Olympus SZX16 stereomicroscope. Anatomical details were examined and photographed with on Olympus BX53 compound microscope and a Canon 7D camera. Genitalia were cleared in boiling KOH for a few minutes to dissolve soft tissues. All the specimens were deposited at the Centre for Behavioural Ecology and Evolution (CBEE), College of Life Sciences, Hubei University, Wuhan, China. All lengths are given in millimetres. Leg and palp measurements are given in the following order: total length (femur + patella + tibia + metatarsus + tarsus).
Abbreviations used:  The females differ from all other Heptathelinae genera by two paired receptacular clusters, all with numerous granula (e.g. Fig. 1C-H) (Xu et al. 2015b).
Species composition. Q. australis (Ono, 2002), Q. nui (Schwendinger & Ono, 2011), Q. baishensis Xu, 2015 Etymology. The species epithet, a noun in apposition, refers to the type locality. Diagnosis. Females of the new species differ from Q. jianfeng sp. n. by the two pairs of receptacular clusters along the anterior margin of bursa copulatrix, which are visible in both dorsal and ventral views ( Fig. 1C-H). It can be distinguished from Q. baishensis and Q. nui by its receptacular clusters with similar size or the middle pair being slightly smaller than the lateral pair. It also differs from all other Qiongthela species in Hainan by its receptacular clusters, all of which have short genital stalks ( Fig. 1C-H). The male is unknown. To facilitate future identification of the species, we provided the DNA barcode for the holotype (XUX-2011-001), which is available on GenBank (Genbank accession code KP229897).
Female genitalia. Two pairs of receptacular clusters along the anterior margin of bursa copulatrix, similar size or the middle pair slightly smaller, with short genital stalks ( Fig. 1C- Etymology. The species epithet, a noun in apposition, refers to the type locality. Diagnosis. Males of the new species differ from all other Qiongthela species by the semioval apophysis at the basal conductor (Fig. 2N, O), from Q. wuzhi sp. n. by a similar rectangular, rather than the basal angle between the two apophyses of tegulum more than 90° (Fig. 2L), by the distal part of contrategulum with two edges, the inner one being dentate and the outer one being sharp (Fig. 2L, M), and by the distal edge of embolus slightly curved (Fig. 2M). Females of the new species differ from all other Qiongthela species by the receptaculuar clusters located slightly on the dorsal wall of the bursa copulatrix, especially the lateral pair being indistinct from the dorsal view ( Fig. 2D-I). The DNA barcode of the paratype (XUX-2012-107) is available on GenBank (Genbank accession code KP229838) for future identification. The DNA barcodes of the holotype (XUX-2014-005) and paratype (XUX-2012-107) are identical (the K2P distance between the two sequences is zero).
Palp. The bulb of four specimens of the new species all relatively distorted. Prolateral side of paracymbium unpigmented and unsclerotised, many setae situated at the tip of paracymbium (Fig. 2J, K). Contrategulum with a proximally irregular dentate edge and two distal edges, the inner one dentate (Fig. 2L, M), the outer one sharp (Fig. 2L, M). Tegulum with a long, pointed, distally directed marginal apophysis with a smooth edge, a proximally directed terminal apophysis narrowing to a slightly bent apex, and the dorsal side of terimal apophysis with dentate edge (Fig. 2L, M). Conductor situated ventro-proximal part of embolus, fused with embolus at the basal portion, distal free, narrowing to a slightly hooked apex (Fig. 2M-O). Embolus largely sclerotised, with a wide, flat opening, curved distal edge (Fig. 2M).
Female (Fig. 2B). Colouration of carapace and opisthosoma similar to or lighter than male according to the age of specimens; chelicerae robust with promargin of cheliceral groove with 9-10 strong denticles of variable size; legs furnished with strong hairs and spines; opisthosoma with 12 tergites, similar to male; seven spinnerets.  Female genitalia. Two pairs of receptacular clusters located slightly on the dorsal wall of the bursa copulatrix, especial the lateral pair indistinct in dorsal view, each receptacular cluster similar size, with or without a genital stalk (Fig. 2D-I Diagnosis. The female of the new species differs from the other Qiongthela species by the receptacular clusters with less granula, the middle pair larger than the lateral pair, the middle pair along the anterior margin of bursa copulatrix, and the lateral pair located on the dorsal wall of the bursa copulatrix ( Fig. 3B-C). The male is unknown. The DNA barcode of the holotype (XUX-2012-106) is available on GenBank (Genbank accession code KP229895) for facilitating future identification of the species. Description. Female (Fig. 3A). Carapace reddish brown in alcohol; opisthosoma light brown; sternum narrow, much longer than wide; a few long pointed hairs running over ocular mound in a longitudinal row; chelicerae robust with promargin of cheliceral groove with ten strong denticles of variable size; legs furnished with strong hairs and spines; opisthosoma with 12 tergites, separated from each other, the first 2-7 larger than others and the fifth largest; seven spinnerets. Measurements: BL 20.50, CL 8.00, CW 7.21, OL 12.40, OW 10.00; ALE > PLE > PME > AME; palp 13.54 (4.70 + 2.43 + 2.80 + 3.61), leg I 15.90 (5.10 + 2.80 + 3.11 + 3.20 + 1.69), leg II 15.35 (4.70 + 2.80 + 2.79 + 3.41 + 1.65), leg III 13.85 (4.35 + 2.10 + 2.60 + 3.00 + 1.80), leg IV 23.71 (7.00 + 3.35 + 4.18 + 6.30 + 2.88).
Female genitalia. The middle receptacular clusters along the anterior margin of bursa copulatrix, the lateral pair located on the dorsal wall of the bursa copulatrix, the middle pair larger than the lateral pair, and the middle pair with short genital stalks (Fig. 3B).
Remarks. This new species was found at the Jianfengling National Forest Park as some specimens of Q. jianfeng sp. n., but at a higher altitude compared with the latter.  Etymology. The species epithet, a noun in apposition, refers to the type locality. Diagnosis. Male of this new species differs from Q. jianfeng sp. n. by the contrategulum with three distal edges (Fig. 4H, J), the basal angle between the two apophyses of tegulum more than 90° (Fig. 4I), and the smooth distal margin of embolus (Fig. 4I).
It differs from Q. baishensis, Q. australi,s and Q. nui by three distal margins of contrategulum (Fig. 4H, J). Females of this new species can be distinguished from the other species of Qiongthela by the receptacular clusters with very short genital stalks, and from Q. bawang sp. n. by the irregular shapes of receptacular clusters (Fig. 4D, E). The DNA barcode of the paratype (XUX-2012-108) is available on GenBank (Genbank accession code KP229812) for future identification. The DNA barcodes of the holotype (XUX-2012-109) and paratype (XUX-2012-108) are identical (the K2P distance between the two sequences is zero).
Description. Male (holotype) (Fig. 4C). Carapace black; opisthosoma light brown; sternum narrow, nearly twice as long as wide; a few long pointed hairs running over ocular mound in a longitudinal row; chelicerae robust with promargin of cheliceral groove with eight denticles of variable size; legs furnished with strong hairs and spines; opisthosoma with 12 tergites, the first 2-7 close to each other and larger than others; seven spinnerets. Palp. Prolateral side of paracymbium unpigmented and unsclerotised, many setae situated at the tip of paracymbium (Fig. 4F. G). Contrategulum with a proximally irregular dentate edge and three distal edges, the inner one dentate, very short, the middle one dentate, running down to the proximally irregular dentate edge of contrategulum, the outer one sharp, fused with the inner one at the middle portion of the middle edge ( Fig. 4H-J). Tegulum with a wide base, pointed, distally directed marginal apophysis with a sharp edge, with a proximally directed terminal apophysis narrowing to a slightly bent apex, and the dorsal side of terminal apophysis with dentate edge (Fig. 4F, G, I, J). Embolus largely sclerotised, with a wide, flat opening, and a sharp distal edge (Fig. 4F-J).
Female genitalia. The two pairs of receptacular clusters along the anterior margin of bursa copulatrix, irregular receptacular clusters with very short genital stalks (Fig. 4D, E).