Solenysa yambaruensis Ballarin & Eguchi, 2025

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), ZooKeys 1232, pp. 97-130 : 97-130

publication ID	https://doi.org/10.3897/zookeys.1232.142629
publication LSID	lsid:zoobank.org:pub:322DDAEF-972B-4D0A-A4F7-C94F029DC196
DOI	https://doi.org/10.5281/zenodo.15040799
persistent identifier	https://treatment.plazi.org/id/9BAB341D-0369-5B00-8C5F-4130077CA5C0
treatment provided by	ZooKeys by Pensoft (2025-03-17 15:24:19, last updated 2025-03-17 20:06:59)
scientific name	Solenysa yambaruensis Ballarin & Eguchi
status	sp. nov.

Treatment

Solenysa yambaruensis Ballarin & Eguchi sp. nov.

Figs 2 A – J View Figure 2 , 4 D-F View Figure 4 , 5 C – F View Figure 5

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 ) GoogleMaps . 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 ) GoogleMaps • 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) GoogleMaps • 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) GoogleMaps • 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) GoogleMaps • 1 ♂, 3 ♀, same locality, 03. Sep. 2023, F. Ballarin leg. ( NSMT -Ar 26190 ) GoogleMaps • 1 ♂, 1 ♀, Ginama , 190 m, 26.82804°N, 128.25471°E, broadleaf forest litter, 04. Sep. 2024, F. Ballarin leg. ( TKPM -AR 3245 ) GoogleMaps • 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) GoogleMaps • 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) GoogleMaps • 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) GoogleMaps • 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) GoogleMaps • 1 ♂, 1 ♀, same locality, 20. Mar. 2024, Z. Touyama & R. Yamauchi leg. ( ZTPC) GoogleMaps • 1 ♀, Hama , 26.70130°N, 128.19685°E, 2. Jan. 2024, Z. Touyama leg. ( ZTPC) GoogleMaps • 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) GoogleMaps .

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 View Figure 2 . 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 View Figure 2 , 4 D-F View Figure 4 , 5 C – F View Figure 5 . 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 View Figure 2 . 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 View Figure 2 , 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 View Figure 2 ).

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 View Figure 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).

References

Simon E (1894) Histoire Naturelle des Araignees, seconde edition. Tome 1, Fascicule 3. Libraire encyclopedique de Roret, Paris, 489 - 760.

Tu LH, Ono H, Li SQ (2007) Two new species of Solenysa Simon, 1894 (Araneae: Linyphiidae) from Japan. Zootaxa 1426: 57-62. https://doi.org/10.11646/zootaxa.1426.1.4

Tu LH, Hormiga G (2011) Phylogenetic analysis and revision of the linyphiid spider genus Solenysa (Araneae: Linyphiidae: Erigoninae). Zoological Journal of the Linnean Society 161 (3): 484-530. https://doi.org/10.1111/j.1096-3642.2010.00640.x

Tu LH, Hormiga G (2011) Phylogenetic analysis and revision of the linyphiid spider genus Solenysa (Araneae: Linyphiidae: Erigoninae). Zoological Journal of the Linnean Society 161 (3): 484–530. https://doi.org/10.1111/j.1096-3642.2010.00640.x

Wang F, Ono H, Tu LH (2015) A review of Solenysa spiders from Japan (Araneae, Linyphiidae), with a comment on the type species S. mellotteei Simon, 1894. ZooKeys 481: 39-56. https://doi.org/10.3897/zookeys.481.8545

Wang F, Ono H, Tu LH (2015) A review of Solenysa spiders from Japan (Araneae, Linyphiidae), with a comment on the type species S. mellotteei Simon, 1894. ZooKeys 481: 39–56. https://doi.org/10.3897/zookeys.481.8545

Figures

Figure 2. Solenysa yambaruensis sp. nov. A male palp, prolateral B ditto, retrolateral C ditto, dorsal D ditto, ventral E habitus of male, dorsal F habitus of female, dorsal G epigyne, posterior H ditto, ventral I ditto, lateral J vulva, dorsal. Abbreviations: CD copulatory duct; DP dorsal plate; DSA distal suprategular apophysis; E embolus; EC epigynal collar; FD fertilization duct; LA 3 posterior branch of lamella; LDP lobe of the dorsal plate; MTA median terminal apophysis; P paracymbium; PBP probasal cymbial apophysis; PTP proximal tibial apophysis; S spermatheca; SL solenoid; STT Solenysа tegular triangle; T tegulum; VLP ventral lobe of P; VP ventral plate. Scale bars: 0.05 mm (A – D, G – J); 0.5 mm (E, F).

Figure 4. Embolic divisions of newly described Solenysa spp. A embolic division of S. shimatchu sp. nov., ventral B ditto, retrolateral C ditto, ventro-prolateral D embolic division of S. yambaruensis sp. nov., ventral E ditto, retrolateral F ditto, ventro-prolateral G embolic division of Solenysa bilamellata sp. nov., ventral H ditto, retrolateral I ditto, ventro-prolateral. Abbreviations: AP anterior protrusion of MTA; ATA anterior terminal apophysis; DSA distal supra-tegular apophysis; E embolus; LA 1 anterior branch of lamella; LA 2 median branch of lamella; LA 3 posterior branch of lamella; MT median tooth on anterior terminal apophysis; MP median protrusion of MTA; MTA median terminal apophysis; PTA posterior terminal apophysis; R radix. Scale bars: 0.05 mm.

Figure 5. Palp and embolic division of Solenysa spp. under SEM microscope A palp of S. shimatchu sp. nov., ventro-retrolateral B ditto, embolic division, ventral C palp of S. yambaruensis sp. nov., ventro-retrolateral D ditto, ventral E ditto, embolic division, ventro-prolateral F ditto, ventral. Abbreviations: ATA anterior terminal apophysis; DSA distal supra-tegular apophysis; E embolus; LA 1 anterior branch of lamella; LA 2 median branch of lamella; LA 3 posterior branch of lamella; MT median tooth on anterior terminal apophysis; MTA median terminal apophysis; P paracymbium; PTA posterior terminal apophysis; R radix; RLP cymbial retrolateral process; STT Solenysa tegular triangle; T tegulum.

Figure 13. Distribution of Solenysa species in the Ryukyu Archipelago and surrounding areas. The Ryukyu Archipelago is marked with a dashed line. Diamonds refer to records of Solenysa spp. from the literature (Shinkai et al. 2024; WSC 2024), dots refer to new records, squares indicate the species type locality, and question marks indicate uncertain records of S. reflexilis.