Taxonomic study of the Pinelemabailongensis species group with descriptions of six new species from China (Araneae, Telemidae)

Abstract The Pinelemabailongensis Wang & Li, 2012 species group of the spider family Telemidae Fage, 1913 from Guangxi and Guizhou, China is revised. Previously, this species group contained two species: P.bailongensis and P.xiushuiensis Wang & Li, 2016. In this study, four species are transferred from Telema Simon, 1882 to Pinelema Wang & Li, 2012, and treated as members of the P.bailongensis species group. They are P.cordata (Wang & Li, 2010) comb. n., P.liangxi (Zhu & Chen, 2002) comb. n., P.strentarsi (Lin & Li, 2010) comb. n. and P.zhewang (Chen & Zhu, 2009) comb. n. Additionally, six new species belonging to the species group are described: P.cheni Zhao & Li, sp. n. (♂♀), P.huoyan Zhao & Li, sp. n. (♂♀), P.lizhuang Zhao & Li, sp. n. (♂♀), P.wangshang Zhao & Li, sp. n. (♂♀), P.wenyang Zhao & Li, sp. n. (♂♀) and P.yunchuni Zhao & Li, sp. n. (♂♀). A key to males is provided.


Introduction
Telemidae Fage, 1913 currently contains 79 species in ten genera worldwide (World Spider Catalog 2018). It has fragmented distributions in rainforest or karst caves of tropical Africa, Eurasia, and the New World (Song et al. 2017a). Pinelema Wang & Li, 2012, the second largest genus of the family, occuring in karst caves or leaf litter. A total of 15 Pinelema species was known from China and Vietnam before the current study.
The P. bailongensis species group, characterized by a distinctly long embolus relative to the bulb, currently contains only two species: P. bailongensis Wang & Li, 2012 and P. xiushuiensis Wang & Li, 2016. The species group is restricted to karst caves in southern Guizhou and western Guangxi, China. In this paper, four species are transferred from Telema Simon, 1882 to Pinelema, and six new species are described.

Material and methods
The individuals of Pinelema bailongensis species group studied here are from the cave expeditions in southern China during last decade.
All specimens were examined and measured using a LEICA M205 C stereomicroscope. All measurements are given in millimeters. Leg measurements are as follows: total length (femur, patella, tibia, metatarsus, tarsus). The habitus, left male palp, and receptacle were photographed using an Olympus C7070 digital camera. Female genitalia were removed and treated in lactic acid before being photographed. Images were combined using Helicon Focus image stacking software. For SEM images, the left male palp was photographed using a Hitachi SU8010 Environmental Scanning Electron Microscope.
To confirm the stable morphology of male palps for each species in the P. bailongensis species group, photos of additional individuals are provided in the supplementary material. Genetic distances were obtained for four to five individuals of each species. Genomic DNA was extracted from the prosomas of females. Standard barcode COI (650 bp) was amplified using the primer pair LCO1490 (5'-GGTCAACAAATCAT-AAAGATATTGG-3') and HCO2198 (5'-TAAACTTCAGGGTGACCAAAAAAT-CA-3') (Folmer et al. 1994). The PCR protocol consisted of initial denaturing of 95 °C for 5 min, 5 cycles of 95 °C for 30 s, 45 °C for 30 s, and 72 °C for 30 s, then 35 cycles of 95 °C for 30 s, 51 °C for 30 s, and 72 °C for 30 s, with a final extension of 72 °C for 5 min. All PCR positive products were purified and sequenced by Tianyihuiyuan Biotech Co., Ltd (Beijing, China) using an ABI 3730 automated sequencer. Raw ABI sequences were edited by hand in BioEdit (Hall 1999). Uncorrected pairwise distances between species in the P. bailongensis species group were calculated using MEGA 5.0 (Tamura et al. 2011). All sequences are deposited in GenBank, and the accession numbers are listed in Table 1.

Pinelema bailongensis species group
Diagnosis. Species of Pinelema bailongensis species group can be distinguished from all other Pinelema species by embolus distinctly longer than bulb and by endogyne Ushaped, J-shaped or spiral. In contrast, embolus of other Pinelema species shorter than bulb and endogyne bag-like.
Comments. Pinelema bailongensis species group is recognized as the first species group in Pinelema according to the long embolus relative to the bulb. Morphologically, the species in this group have quite simple and almost identical copulatory organs, only proportions of the bulb and its parts can help to separate the species, endogynes can not be used for distinguishing species (except P. bailongensis and P. wangshang Zhao & Li, sp. n.). Genetically, each species in this group owns very significant difference comparing the congeners (Table 1). Diagnosis. Pinelema bailongensis resembles P. cordata (see Figure 5 and Wang and Li 2010: 9, figs 11-15) but can be distinguished by following characters: small apophyses present on embolus distal-retrolaterally (see Song et al. 2017b: figure 8A and Wang and Li 2012: figure 4) (apophyses absent on embolus distal-retrolaterally in P. cordata), larger Esl/El ratio (0.58-0.62, n = 5, mean: 0.60, Suppl. material 1: Figure S1) (smaller Esl/El ratio 0.51-0.54, n = 5, mean: 0.52 in P. cordata), and shape of receptacle spiral (see Wang and Li 2012: figs 8, 11) (receptacle U-shaped in P. cordata).
Comments. This species is transferred to Pinelema because it shares similar morphological characters with P. bailongensis, such as the long, tube-shaped embolus (see Figure 5 and Wang and Li 2010: figs 11A-B, 12B), the presence of a distinct cymbial apophysis in the male palp prolaterally (see Figure 5A and Wang and Li 2010: figure  11B), and the U-shaped and medially strongly curved receptacle (see Wang and Li 2010: figure 13).
Comments. Because this species shares similar morphological characters with P. bailongensis, such as the long, tube-shaped embolus (see Remarks. The coordinates of the type locality of this species in Zhu and Chen (2002) is wrong because they refer to the place located approximately 700 kilometers from Liangxi Cave. The coordinate information reported here is confirmed by Dr H. Chen who collected type material.
Comments. This species is transferred to Pinelema, because it shares similar morphological characters with P. bailongensis, such as the long, tube-like embolus (see Figs 15A-D, 16C-D and Lin and Li 2010: figure 14D-F), the presence of a distinct cymbial apophysis in male palp prolaterally (see Figs 15A, 16C and Lin and Li 2010: figure 14E), and the U-shaped and medially strongly curved receptacle (see Figure 17C and Lin and Li 2010: figure 15F).