Three new species of the genus Leptonetela from Greece (Araneae, Leptonetidae)

Abstract Three new species of the spider genus Leptonetela collected from caves in Greece are described: Leptonetela arvanitidisi sp. n. (male & female), Leptonetela paragamiani sp. n. (male & female) and Leptonetela penevi sp. n. (male & female). Detailed illustrations of the new species are provided. DNA barcodes were obtained for future use.


Introduction
The leptonetids are minute (1.0-3.0 mm) spiders that can be easily distinguished from other families by a distinctive 6-eyed pattern, with the posterior median eyes situated behind the posterior lateral eyes; however, in some cave species, the eyes are reduced to vestiges or may be completely absent (Gertsch 1974).
A total of 23 genera and 276 species of the spider family Leptonetidae are known worldwide (World Spider Catalog 2016). The genus Leptonetela was established by Kratochvíl (1978), using Leptonetela kanellisi (Deeleman-Reinhold, 1971) from a cave in Greece as the type species. Leptonetela can be distinguished from other genera of the family by the palpal femur without spines, the retrolateral surface of the palpal tibia with a longitudinal row of strong spines and the male palpal tarsus without appendices.
A total of 50 Leptonetela species are known from Europe and Asia. Two species of Protoleptoneta were transferred to Leptonetela by Brignoli in 1979: L. strinatii (Brignoli, 1976) from Greece and L. deltshevi (Brignoli, 1979) from Turkey. Deltshev described L. andreevi from Greece in 1985. Dunin (1990) reported L. caucasica from Georgia and Azerbaijan. L. thracia was described by Gasparo in 2005 from Greece. Subsquently, Lin and Li (2010) described 24 species occurring in the Yunnan-Guizhou Plateau, China, including L. quinquespinata (Chen & Zhu, 2008) which was transferred from Qianleptoneta Chen & Zhu, 2008. Wang and Li (2011) reported 17 Leptonetela species from South China, 2 species from Greece and 1 species from Vietnam.
Other than L. deltshevi (Brignoli, 1979) from Turkey and L. pungitia Wang & Li, 2011 from Vietnam which have been collected in epigean habitats, all species are found in caves. Some of them have characters typical to true troglobites, such as lacking eyes and pigmentation and elongated legs.
In this paper, three Leptonetela species collected from caves in Greece are described as new to science. The total number of Leptonetela species from Europe reaches 9 species.

Material and methods
Specimens were examined with a LEICA M205C stereomicroscope. Images were captured with an Olympus C7070 wide zoom digital camera (7.1 megapixels) mounted on an Olympus SZX12 dissecting microscope. Epigynes and male palps were examined after dissection from the spiders' bodies.
Terminology and abbreviations in this paper gen erally follow Wang and Li (2011) and Ledford (2011). The unit of measurement in this paper is millimetres (mm). Leg metric data were recorded as total length (femur, patella, tibia, metatarsus, tarsus). Leg segments were measured on their dorsal side.
The specimens studied in the current paper are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS) in Beijing, China. Diagnosis. Leptonetela arvanitidisi sp. n. is similar to L. kanellisi but can be separated by the basal tibial spine with bifurcated tip (Fig. 1D) (not bifurcated in L. kanellisi), the wave-shaped anterior margin of the atrium and the tightly twisted spermathecae (Fig. 2C); L. kanellisi has an arc-shaped anterior margin of the atrium and the spermathecae are loosely twisted (see Wang and Li 2011: figs 16-19).
Female (one of the paratypes). Similar to male in color and general features but larger and with shorter legs. Total length 2.03 ( Fig. 2A-B) (Fig. 2C): spermathecae coiled, atrium fusiform, anterior margin of the atrium wave shaped.
Distribution. Known only from the type locality.   Diagnosis. Leptonetela paragamiani is similar to L. kanellisi and L. arvanitidisi sp. n. but can be separated by the second tibial spine, which is longest in L. paragamiani sp. n., whereas in L. kanellisi and L. arvanitidisi sp. n. (Fig. 3D) the basal spine is longest; the median apophysis has 3 small teeth (Fig. 3B) in L. paragamiani sp. n., whereas it has 6 teeth in L. kanellisi and L. arvanitidisi sp. n.; and the spermathecae are tightly twisted (Fig. 4C) compared to the spermathecae of L. kanellisi and L. arvanitidisi sp. n.
Female (one of the paratypes). Similar to male in color and general features but larger and with longer legs. Total length 1.88 (Fig. 4A-B)      Etymology. The specific name is dedicated to Prof. Dr. Lyubomir Penev, zoologist and founder of Pensoft Publishers; noun (name) in genitive case. Pensoft Publishers is a leading company in publishing taxonomic works.
Diagnosis. Leptonetela penevi sp. n. is similar to L. kanellisi and L. paragamiani sp. n. but can be separated by having the basal tibial spine longer than others, and slender ( Fig. 5D) compared to the basal spines of L. kanellisi and L. paragamiani sp. n.; median apophysis distally without teeth (Fig. 5D) and spermathecae strongly twisted and longer than those of L. kanellisi and L. paragamiani sp. n. (Fig. 6C).
Distribution. Known only from the type locality.