Solenysa yambaruensis Ballarin & Eguchi 2025, sp. nov.
Creators: name: Ballarin, Francesco
name: Liao, Hauchuan
name: Touyama, Zento
name: Eguchi, Katsuyuki
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Linyphiidae
Solenysa
Solenysa yambaruensis

description: Solenysa yambaruensis Ballarin & Eguchi sp. nov.
Figs 2 A – J, 4 D-F, 5 C – F
Material examined.
Holotype ♂. Japan: • Okinawa Pref., Okinawa Is., Kunigami Distr., Kunigami Vill., Yona, Yambaru National Park, 185 m, 26.74755°N, 128.22347°E, humid forest litter, 25. Feb. 2021, F. Ballarin leg. (NSMT -Ar 26188). Paratypes. Japan: Okinawa Pref., Okinawa Is., • 1 ♀, Kunigami Distr., Kunigami Vill., Yona, Yambaru National Park, 185 m, 26.74755°N, 128.22347°E, humid forest litter, 25. Feb. 2021, F. Ballarin leg (NSMT -Ar 26189) • 3 ♀, same locality, 46 m, 26.7601°N, 128.2190°E, 03. Sep. 2023, humid forest leaf litter along the road, tullgren funnel, R. Itou, R. Kaneko, Y. Hiruma, and K. Watanabe leg. (MNHAH) • 2 ♀, same locality, 240 m, 26.74335°N, 128.22608°E, humid broadleaf litter near a small creek, 02. Sep. 2024, F. Ballarin leg. (FBPC) • 1 ♂, Sate, 80 m, 26.78245°N, 128.22061°E, broadleaf forest litter on a slope with rocks, 13. May. 2022, F. Ballarin leg. (FBPC) • 1 ♂, 3 ♀, same locality, 03. Sep. 2023, F. Ballarin leg. (NSMT -Ar 26190) • 1 ♂, 1 ♀, Ginama, 190 m, 26.82804°N, 128.25471°E, broadleaf forest litter, 04. Sep. 2024, F. Ballarin leg. (TKPM -AR 3245) • 1 ♂, 1 ♀, same locality, 210 m, 26.82743°N, 128.25885°E, pine forest litter, 04. Sep. 2024, F. Ballarin leg. (MSNVR -Ar 036 –037) • 3 ♀, Oku, Ryukyu University Okuyamaso, 26.8365°N, 128.2715°E, 03. Sep. 2023, forest leaf litter, sifter, R. Itou, R. Kaneko, Y. Hiruma, and K. Watanabe leg. (MNHAH) • 1 ♂, Nago, 10. Nov. 2018, A. Tanikawa leg. (MNHAH)
Other material examined.
Japan: Okinawa Pref., Okinawa Is., • 1 ♀, Nago, 13. Nov. 2007, A. Tanikawa leg. (MNHAH); • 1 ♀, same locality, 6. Nov. 2009, A. Tanikawa leg. (MNHAH) • 1 ♀, same locality, 8. Dec. 2009, A. Tanikawa leg. (TKPM) • 1 ♀, same locality, 21. Oct. 2010, A. Tanikawa leg. (TKPM) • 1 ♂, same locality, 15. Apr. 2011, A. Tanikawa leg. (TKPM) • 1 ♂, 1 ♀, Onna, Tancha, near OIST campus, 140 m, 26.45947°N, 127.83674°E. mixed forest litter along the road, 30. Aug. 2023, F. Ballarin leg. (FBPC) • 1 ♂, Kunigami Distr., Kunigami Vill., Hama, Near Nagao-Bashi Bridge, 26.70897°N, 128.19708°E, 2. Jan. 2024, forest litter, Z. Touyama leg. (ZTPC) • 1 ♂, 1 ♀, same locality, 20. Mar. 2024, Z. Touyama & R. Yamauchi leg. (ZTPC) • 1 ♀, Hama, 26.70130°N, 128.19685°E, 2. Jan. 2024, Z. Touyama leg. (ZTPC) • Kumejima Is., 1 ♀, Shimajiri-gun, Maja, 95 m 26.34819°N, 126.80254°E, litter in a broadleaf forest, 18. May. 2022, F. Ballarin leg. (FBPC).
Diagnosis.
See the diagnosis of S. shimatchu sp. nov. above.
Description.
Male (holotype). Total length: 1.24. Prosoma 0.68 long; 0.47 wide. Clypeus 0.24 long. Habitus as in Fig. 2 E. Length of legs as follows: I 2.62 (0.69, 0.15, 0.70, 0.59, 0.49), II 2.31 (0.64, 0.15, 0.57, 0.50, 0.45), III 1.81 (0.51, 0.14, 0.41, 0.40, 0.36), IV 2.21 (0.64, 0.14, 0.53, 0.48, 0.42). Opisthosoma uniformly greyish with three distinct, white-greyish marks on dorsal side: two wide parallel, elongated marks in the central-anterior part of opisthosoma, one wide mark near posterior tip. Marks partially fused together in some individuals. Other somatic characters as in species group.
Palp as in Figs 2 A-D, 4 D-F, 5 C – F. Proximal tibial apophysis (PTP) slightly protruding, bearing three spines. Probasal cymbial apophysis (PBP), massive, strongly bent, hook-like when observed dorsally, headed antero-retrolaterally. Ventral lobe of paracymbium (VLP) wide, laterally flattened, strongly protruding antero-ventrally. Lamella with three well-developed branches: LA 1 transparent and wide, ribbon-like, half-twisted; LA 2 and LA 3 both sclerotized; LA 2 thin, strait, needle-like, headed antero-ventrally; LA 3 longer, basal part wide, ribbon-like, headed antero-retrolaterally, ending with two small denticles and one sharp needle-like tip bent with a 90 ° angle antero-dorsally. Posterior terminal apophysis (PTA), thin and transparent, headed anteriorly, clearly visible when the palp is observed ventrally. Median terminal apophysis (MTA) flattened, long and lobated, sightly sclerotized, strongly protruding antero-ventrally. Anterior terminal apophysis (ATA) ribbon-like, strongly sclerotized, flattened, slightly twisted, headed ventrally, ending with a blunt tip. Median tooth (MT) of ATA small, thorn-like with a sharp tip, headed posteriorly. Embolus (E) transparent, twisted, and fringed, partially hidden by ATA.
Female (one of the paratypes). Total length: 1.25. Prosoma 0.63 long; 0.44 wide. Clypeus 0.21 long. Habitus as in Fig. 2 F. Length of legs as follows: I 2.42 (0.65, 0.15, 0.63, 0.52, 0.47), II 2.07 (0.52, 0.14, 0.51, 0.46, 0.44), III 1.73 (0.45, 0.12, 0.41, 0.37, 0.38), IV 2.06 (0.55, 0.14, 0.50, 0.45, 0.42). Color and other features as in male.
Epigyne and vulva as in Fig. 2 G-J, flattened and only slightly protruding when observed laterally. Solenoid (SL) folded anterodorsally with 2 transversal folds before reaching the dorsal base of epigyne. Ventral plate (VP) trapezoidal with rounded lateral borders, anterior border concave, ventral border flattened. Dorsal plate (DP) undivided, bearing a short, rectangular ventral lobe (LDP) slightly protruding posteriorly. Copulatory ducts (CD) thick, heading anteriorly then posteriorly before reaching posterior side of spermathecae. Fertilization ducts (FD) thin, S-shaped, slightly twisted, bent anteriorly. Spermathecae (S) wide, oval (Fig. 2 J).
Etymology.
The specific name is derived from the type locality area where this species was initially found, the Yambaru National Park. This renowned protected area covers the Northern portion of Okinawa Island and has been included in the UNESCO World Heritage List since 2021.
Distribution.
Endemic to Okinawa Honto and Kumejima islands, Central Ryukyus, Japan (Fig. 13).
Habitat.
Humid leaf litter on the floor of broadleaved and mixed forests.
Solenysa mellotteei group sensu Tu & Hormiga (2011)
Composition. Seven species: Solenysa mellotteei Simon, 1894; S. macrodonta Wang, Ono & Tu, 2015; S. ogatai Ono, 2011; S. partibilis Tu, Ono & Li, 2007; S. reflexilis Tu, Ono & Li, 2007; S. trunciformis Wang, Ono & Tu, 2015; S. bilamellata sp. nov.
Diagnosis. See Tu and Hormiga (2011) and Wang et al. (2015).
Description. See Tu and Hormiga (2011) and Wang et al. (2015).
Distribution. Mainland Japan (Honshu, Shikoku, Kyushu, absent in Hokkaido).
description: Published as part of Ballarin, Francesco, Liao, Hauchuan, Touyama, Zento & Eguchi, Katsuyuki, 2025, Review of the spider genus Solenysa Simon, 1894 in Western Japan and Central Ryukyu with the description of three new species (Araneae, Linyphiidae), pp. 97-130 in ZooKeys 1232 on pages 97-130, DOI: 10.3897/zookeys.1232.142629