﻿Two new species of the genus Cheiracanthium C. L. Koch, 1839 (Araneae, Cheiracanthiidae) from China

﻿Abstract Two species of the long-legged sac spider genus Cheiracanthium C. L. Koch, 1839 collected from China are diagnosed and described as new to science: Cheiracanthiumbannaensissp. nov. (♂♀) from Yunnan Province and C.bifurcatumsp. nov. (♂♀) from Xinjiang Uyger Autonomous Region. Photos of the habitus and copulatory organs are given. In addition, DNA barcode information of the two new species is provided.


Introduction
The genus Cheiracanthium C. L. Koch, 1839 is widely known and mainly distributed in the Old World (World Spider Catalogue;WSC 2024).Compared to other genera in Cheiracanthiidae Wagner, 1887, Cheiracanthium is the largest, accounting for 60% of the species diversity (220 out of 369 species described in the family) (WSC 2024).Members of Cheiracanthium are known as long-legged sac spiders, as they have long and slender legs, and build sac-like silk nests on plant leaves (Lotz 2007a).
Although several studies on Cheiracanthium have been published in the last few years (Deeleman-Reinhold 2001;Lotz 2007aLotz , 2007bLotz , 2011Lotz , 2014Lotz , 2015;;Chen and Huang 2012;Bayer 2014;Zhang et al. 2018Zhang et al. , 2020;;Li and Zhang 2019, 2020, 2023, 2024;Esyunin and Zamani 2020;Dippenaar-Schoeman et al. 2021), the global diversity of this genus is still insufficiently known, and there are likely many other, as yet undiscovered species.Currently, 47 species of Cheiracanthium have been recorded from China, of which 12 species are known based on a single female (8) or male (4) (WSC 2024).Therefore, the identification of species and correct sex matching in Cheiracanthium are often challenging.
In the present paper, two new species of Cheiracanthium from China are recognized and described here: Cheiracanthium bannaensis sp.nov.and C. bifurcatum sp.nov.In addition, the DNA barcode gene, cytochrome c oxidase subunit I (COI) of new species is given, as DNA information is useful for the identification of species and for correctly matching sexes (Lo et al. 2021;Li and Zhang 2023)

Material and methods
All specimens were preserved in 75% ethanol and examined and measured under a Leica M205A stereomicroscope.Photographs were taken using an Olympus BX51 microscope equipped with a Kuy Nice CCD camera and were imported into Helicon Focus v.7 for stacking.Final figures were retouched using Adobe Photoshop 2020.All measurements are given in millimeters.Leg measurements are shown as: total length (femur, patella, tibia, metatarsus, tarsus).Epigynes were removed and cleared in a pancreatin solution.All specimens studied are deposited in the Museum of Hebei University (MHBU), Baoding, China.
Morphological terminology follows Zhang et al. (2020) and Li and Zhang (2023) A DNA barcode was also obtained for species delimitation and matching of different sexes.A partial fragment of the mitochondrial cytochrome oxidase subunit I (CO1) gene was amplified and sequenced using the primers LCO1490/ HCO2198 (Folmer et al. 1994).For additional information on extraction and amplification see Li and Zhang (2023).All PCR products were purified and sequenced at Sangon Biotech (Shanghai, China) Co., Ltd.
Sequence alignments were carried out using Mafft v.7.313 (Katoh and Standley 2013) with the L-INS-I strategy and checked for the presence of stop codons of COI by translating them into amino acid sequence using Geneious Prime (Kearse et al. 2012).Ambiguously aligned positions were culled using tri-mAl v. 1.2 (Capella-Gutierrez et al. 2009) with default parameters.The pairwise genetic distances (Kimura two-parameter [K2P]) were calculated using MEGA v.11 (Tamura et al. 2021) to assess the genetic differences.

DNA barcodes
All sequences were deposited in GenBank.The accession numbers of the generated DNA barcodes are provided in Table 1.The K2P genetic distance of intraspecific and interspecific nucleotide divergences of C. bannaensis sp.nov.and C. bifurcatum sp.nov.are shown in Table 2.
The intraspecific genetic distance ranged from 0 to 1.85%, and the interspecific genetic distance ranged from 13.82% to 14.78%.The maximum intraspecific distances were much lower than the minimum interspecific distances.The results of Kimura two-parameter genetic distances confirm the correct matching of male and female of two new species.Etymology.The species name is a toponym in apposition referring to the type locality.
Epigyne (Fig. 2C-E).Atrium large, located at middle portion of epigynal plate, filled with mating plug; arched atrial lateral margins are easily visible after removing the plug.Copulatory openings located at lateral margins of atrium.Copulatory duct visible through tegument of epigynal plate in ventral view.Spermathecae large, banana-shaped, c. two times longer than wide.Copulatory ducts coiled, forming about three ascending turns and then descending into the spermathecae.Fertilization ducts lamellar, broad, originate from posterior parts of spermathecae.
Distribution.China (Yunnan).Etymology.The specific epithet is an adjective from the Latin 'bifurcate', referring to the distally bifurcated retrolateral tibial apophysis in ventral view.

Figure 4 .
Figure 4. Habitat (A) and living specimens (B-E) of Cheiracanthium bifurcatum sp.nov.A camelthorn steppe in Aksu B, C male holotype D, E female paratype, with arrow pointing to egg sac.

Table 2 .
Intraspecific and interspecific nucleotide divergences for C. bannaensis sp.nov.and C. bifurcatum sp.nov.using the Kimura two-parameter model.