Solenysa, SIMON, 1894

Tu, Lihong & Hormiga, Gustavo, 2011, Phylogenetic analysis and revision of the linyphiid spider genus Solenysa (Araneae: Linyphiidae: Erigoninae), Zoological Journal of the Linnean Society 161 (3), pp. 484-530 : 494-497

SOLENYSA SIMON, 1894

Solenysa Simon, 1894: 677 .

Type species: Solenysa melloteei Simon, 1894 .

Composition: Twelve species, including five new species described here: Solenysa akihisai Tu sp. nov., Solenysa geumoensis Seo, 1996 , Solenysa lanyuensis Tu sp. nov., Solenysa longqiensis Li & Song, 1992 , Solenysa melloteei Simon, 1894 , Solenysa partibilis Tu et al., 2007 , Solenysa protrudens Gao et al., 1993 , Solenysa reflexilis Tu et al., 2007 , Solenysa retractilis Tu sp. nov., Solenysa tianmushana Tu sp. nov., Solenysa wulingensis Li & Song, 1992 , and Solenysa yangmingshana Tu sp. nov.

Diagnosis: Solenysa species can be distinguished from all other linyphiids by the four lateral lobes on each side of the carapace and by the tubular-shaped petiole ( Fig. 16A–C ). Males are also diagnosed by the palpal cymbium, which has a large probasal process and a small retrolateral process that is articulated with the paracymbium ( Fig. 12A ). Females are also diagnosed by the long membranous solenoid, which connects the epigynum to the abdomen, twists and lifts the epigynum up in nonfunctional stage ( Figs 8H, 13A ; see also Tu & Li, 2006b: figs 28–30).

Description: Small spiders, male total length 1.11– 1.61, female 1.27–1.90. Both sexes similar in general appearance with little interspecies variation ( Fig. 16A–C ): cephalic region of both sexes turret-like, raised bearing AMEs in front, PMEs on top, ALEs and PLEs on its sides; AMEs black and very small, AMEd about half of other eyes, rest of eyes subequal; AER recurved, AME-AME less than AMEd, AME-ALE longer, PER straight, PME-PME equal to PMEd, PME-PLE shorter, ALE and PLE juxtaposed. Many impressed, round pits scattered on carapace and anterolateral surface of chelicerae ( Fig. 18B ). Posterior part of carapace elongated into a tubular-shaped petiole. Sternum continuous with carapace laterally, leaving four openings at each side through which coxae are articulated. In dorsal view four lobes can be distinguished around the leg coxae ( Fig. 16A–C ), but not conspicuous in S. longqiensis ( Fig. 14A ) and S. yangmingshana sp. nov. Legs long and slender, without macrosetae. Patella I–IV with one distal short spine ( Fig. 16B ). Tm I 0.17–0.26. Tm IV absent. Female palpal claw absent ( Figs 14E , 16D ). Book lung cover almost smooth ( Fig. 12G ). Epiandrous fusules absent in males (studied in S. partibilis , Fig. 12H; S . longqiensis, Fig. 15H; S . protrudens, Fig. 17E; S . retractilis and S. wulingensis , Fig. 20E ). Tracheal system consisting of unbranched median and lateral trunks; median pair slightly wider in diameter than lateral pair, extending into prosoma through petiole (studied in S. partibilis ; S. akihisai ; S. longqiensis ; S. protrudens , Fig. 16A; S . retractilis, Fig. 18C; S . wulingensis, Fig. 20A ). Spinnerets (studied in S. partibilis ; S. longqiensis ; S. protrudens ; S. retractilis ; and S. wulingensis ): ALS with one major ampullate gland spigot and one nubbin, as well as about 12 piriform gland spigots ( Fig. 16E ); PMS with one minor ampullate gland spigot ( Fig. 16G ), cylindrical gland spigot present ( Fig. 20G ) or not ( Fig. 16G ); PLS with four aciniform gland spigots between the two cylindrical gland spigots ( Fig. 16F ); basal part of mesal cylindrical gland spigot slightly larger than distal one ( Fig. 16F ); flagelliform and aggregate gland spigots (‘araneoid triplet’) well developed in females ( Fig. 16F ), reduced to nubbins in adult males ( Fig. 16H ), but present in adult males of S. retractilis ( Fig. 18F ) and S. wulingensis ( Fig. 20F ). Male palpal tibia with one prolateral, two retrolateral trichobothria ( Fig. 21A ). Proximal part of cymbium extending posteriorly and then turning retrolaterally, forming a large excavation and probasal process, protruding out ( Fig. 15A–C ), or hidden ( Fig. 21A ). Small retrolateral process anterior to proximal part of paracymbium ( Fig. 12A ). Paracymbium U-shaped, curved almost horizontally ( Fig. 15B ) or torsion-shaped turning in the middle ( Fig. 21A ) with additional curve at proximal part that articulates with cymbial retrolateral process ( Fig. 21A ). Tegulum with a chitinized triangular structure in retrolateral view, termed here as ‘S olenysa tegular triangle’ ( Fig. 16A ). Distal suprategular apophysis large, extending ventrally in retrolateral view ( Fig. 19A ). Radix usually small, combined with other elements of embolic division ( Fig. 15D ) or even embedded in a large membranous area that connects the basal part of terminal apophysis and lamella characteristica ( Figs 10D, 19E ). Terminal apophysis with three free ends, normally the median one larger ( Fig. 7). Lamella characteristica deeply divided into three well-developed branches, at least one of them, usually the median branch, ribbon like ( Fig. 7). Embolus short, sclerotized ( Fig. 12F ), translucent (less sclerotized) or totally membranous ( Fig. 19E, F ), without pointed embolus proper. No embolic membrane arising from column, but sometimes embolus with membranous projection, the distal embolar membrane (‘M’, see Figs 15F , 17D ). Epigynum well sclerotized, encapsulated, hanging at distal end of a long, transversally wrinkled, membranous solenoid ( Fig. 13A ). Solenoid arising from abdomen tegument, twisting and lifting epigynum up in nonfunctional stage ( Figs 8H, 13A ; see also Tu & Li, 2006b: figs 28–30). A pair of seams on epigynal dorsal surface; curved ( Fig. 13B ) or straight ( Fig. 14H ), transversal ( Fig. 17G ) or longitudinal ( Fig. 14H ); distal ends served as copulatory openings, proximal ends as fertilization openings. Fertilization ducts directed mesally ( Fig. 8I).

Remarks: The somatic morphology of Solenysa is quite uniform across species and shows little sexual dimorphism, although some of these features can be found in other linyphiids. For example, various types of cephalic lobes can be found in the males of other erigonine lineages (see Hormiga, 2000: figs 32–35), whereas in Solenysa the cephalic lobe is found in both sexes. The round pits on the carapace and chelicerae of Solenysa are also present in several not closely related taxa [e.g. in Lophomma punctatum (Blackwall) , see Hormiga, 2000: plate 47], but those of Solenysa have a flat bottom, and no seta arises from it ( Fig. 18B ). The tubular-shaped carapace petiole

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also can be found in Cresmatoneta mutinensis (Canestrini, 1868) . The simultaneous presence of these and other somatic characters is unique to Solenysa , which makes this genus easily distinguishable from all other linyphiids.

In contrast to other erigonines, the radix in Solenysa is very reduced, to the extent that often it is not easy to distinguish it, and it is either combined with the terminal apophysis ( Fig. 15D ), or it becomes embedded in the membranous area which connects the basal part of the well-developed terminal apophysis and lamella characteristica ( Fig. 19E ). In the latter case, observed under the compound microscope, the radix is only a small, chitinized structure in the translucent area between the terminal apophysis and the lamella characteristica ( Fig. 10D). Although this is not discernable in SEM images, it can be dissected out for examination. In fact, in one of our previous studies ( Tu & Li, 2006b), we had totally missed the radix and incorrectly homologized the forward extending anterior branch of the lamella characteristica as the radix ( Tu & Li, 2006b: figs 8, 27, 46). Here we have corrected this mistake and have relabelled each structure with its correct morphological term ( Fig. 7). Consequently, the structure labelled as ‘R’ in Tu & Li (2006b: fig. 8, 18, 27, 46) is relabelled here as LC 1; ‘ LC 1 ’ and ‘ LC 3 ’ in Tu & Li (2006b: figs 8, 18, 27, 46) are relabelled here as LC 3 and posterior terminal apophysis, respectively.

We document the presence of internal abdominal structures that we have interpreted to be of glandular nature (‘special glands’; see Fig. 20A, E ). These structures, visible after enzymatic digestion of abdominal tissues, can be found in a pair of clusters at or near the base of the PLS. We found these structures in females of S. longqiensis and in males of S. wulingensis .

Phylogenetics: Solenysa falls within the ‘distal erigonines’ clade and its monophyly is unambiguously supported by numerous putative synapomorphies (see Discussion). The 12 Solenysa species are grouped into four clades ( Figs 5 , 6 ): the S. melloteei , S. longqiensis , S. protrudens , and S. wulingensis groups, each with a distinct genitalic pattern.

Natural history: Solenysa species build small webs at base of grasses, above ground. They also can be found in leaf-litter by sifting.

Distribution: The distribution of Solenysa species shows conspicuous regionality ( Fig. 22 ). To date, all Solenysa species have been recorded from 22.70°– 37.74°N, 102.70°– 139.30°E. The S. wulingensis clade includes four species distributed in the south-east of the mainland of China and Korea Peninsula; the S. melloteei clade includes four species only found in Japan; the S. longqiensis clade and the S. protrudens clade, each including two species, are distributed on both sides of the Taiwan Channel. Every species is limited to its type locality and the adjacent area; none of them is widely distributed, but this could very well be the result of insufficient sampling.

Figures

Figure 5. The single most parsimonious tree that results from the analysis of Matrix 2 (Appendix 4) under equal weights [length (L) = 154, consistency index (CI) = 0.79, retention index (RI) = 0.89]. Ambiguous character transformations are optimized under Farris optimization in WINCLADA. Black circles represent nonhomoplasious character changes; white circles represent homoplasious character changes.

Figure 6. Carapace morphology of Solenysa and the genitalic patterns of the four Solenysa clades mapped on the single most parsimonious tree.

Figure 12. Solenysa partibilis. A–F, male palp: A, retrolateral; B, ventral; C, detail of A; D, anterior; E, detail of B; F, detail of D (arrow indicates sperm duct in embolus). G, anterior part of male abdomen showing epiandrous fusules absent and smooth book lung cover. H, detail of G. Abbreviations: ATA, anterior terminal apophysis; DSA, distal suprategular apophysis; E, embolus; LC1, anterior branch of lamella characteristica; LC2, median branch of lamella characteristica; LC3, posterior branch of lamella characteristica; MTA, median terminal apophysis; P, paracymbium; PBP, cymbial probasal process; PTA, posterior terminal apophysis; PTP, proximal tibial process; RLP, cymbial retrolateral process; STT, Solenysa tegular triangle; T, tegulum. Scale bars in mm.

Figure 13. Solenysa partibilis. A–D, epigynum: A, ventral; B, dorsal; C, caudal; D, detail of C. E–H, spinnerets: E, male; F, female; G, female ALS; H, female PLS. Abbreviations: AC, aciniform gland spigot(s); AG, aggregate gland spigot(s); ALS, anterior lateral spinneret; CY, cylindrical gland spigot(s); DP, dorsal plate; FO, fertilization opening; FL, flagelliform gland spigot(s); mAP, minor ampullate gland spigot(s); MAP, major ampullate gland spigot(s); PI, piriform gland spigot(s); PLS, posterior lateral spinneret; PMS, posterior median spinneret; SL, solenoid; VP, ventral plate. Scale bars in mm.

Figure 14. Solenysa longqiensis. A–C, female prosoma: A, dorsal; B, ventral; C, frontal. D, female chelicera, ectal. E, female palp. F, solenoid cover, anterior. G–H, epigynum: G, ventral; H, dorsal. Abbreviations: CO, copulatory opening; DP, dorsal plate; SC, solenoid cover; SL, solenoid. Scale bars in mm.

Figure 15. Solenysa longqiensis. A–C, male palp with embolic division removed: A, prolateral; B, retrolateral (arrow indicates cymbial basal excavation); C, dorsal. D–F, male embolic division: D, ventral; E, dorsal; F, detail of D. G, female spinnerets. H, anterior part of male abdomen showing epiandrous fusules absent. Abbreviations: AC, aciniform gland spigot(s); AG, aggregate gland spigot(s); ALS, anterior lateral spinneret; ARP, anterior radical process; ATA, anterior terminal apophysis; CY, cylindrical gland spigot(s); DSA, distal suprategular apophysis; E, embolus; FL, flagelliform gland spigot(s); LC1, anterior branch of lamella characteristica; LC2, median branch of lamella characteristica; LC3, posterior branch of lamella characteristica; M, distal membrane of embolus; MAP, major ampullate gland spigot(s); MTA, median terminal apophysis; P, paracymbium; PBP, cymbial probasal process; PI, piriform gland spigot(s); PLS, posterior lateral spinneret; PMS, posterior median spinneret; PTA, posterior terminal apophysis; R, radix; RLP, cymbial retrolateral process; SPT, suprategulum; STT, Solenysa tegular triangle; T, tegulum. Scale bars in mm.

Figure 16. Solenysa protrudens. A, female body, dorsal (anterior arrow, lateral lobe of carapace; posterior arrow, median pair tracheae extending into prosoma through petiole). B–C, female prosoma: B, lateral; C, ventral (arrow, sternum connected with carapace around legs coxae). D, female palp. E–H, spinnerets: E, female ALS; F, female PLS; G, female PMS; H, male PMS and PLS (arrow, triplet nubbin). Abbreviations: AC, aciniform gland spigot(s); AG, aggregate gland spigot(s); CY, cylindrical gland spigot(s); FL, flagelliform gland spigot(s); mAP, minor ampullate gland spigot(s); MAP, major ampullate gland spigot(s); PI, piriform gland spigot(s); PLS, posterior lateral spinneret; PMS, posterior median spinneret. Scale bars in mm.

Figure 17. Solenysa protrudens. A, male palp, retrolateral (arrow, paracymbial proximal curve). B, female chelicerae, ectal. C, male palpal embolic division, ventral. D, detail of C. E, anterior part of male abdomen showing epiandrous fusules absent. F–H, epigynum: F, ventral; G, dorsal; H, caudal. Abbreviations: ARP, anterior radical process; ATA, anterior terminal apophysis; CO, copulatory opening; DSA, distal suprategular apophysis; E, embolus; LC1, anterior branch of lamella characteristica; LC2, median branch of lamella characteristica; LC3, posterior branch of lamella characteristica; M, distal membrane of embolus; MTA, median terminal apophysis; P, paracymbium; PBP, cymbial probasal process; PTA, posterior terminal apophysis; PTP, proximal tibial process; R, radix; RLP, cymbial retrolateral process; SL, solenoid; STT, Solenysa tegular triangle; T, tegulum. Scale bars in mm.

Figure 18. Solenysa retractilis sp. nov. A, male chelicerae, ectal. B, pits on carapace. C, female tracheal system. D, epigynum, ventral. E–H, spinnerets: E, male; F, female; G, male PLS; H, female PMS. Abbreviations: AG, aggregate gland spigot(s); ALS, anterior lateral spinneret; CY, cylindrical gland spigot(s); mAP, minor ampullate gland spigot(s); PLS, posterior lateral spinneret; PMS, posterior median spinneret. Scale bars in mm.

Figure 19. Solenysa retractilis sp. nov. A–D, male palp: A, retrolateral (arrow, paracymbial proximal curve); B, prolateral; C, ventral (arrow, basal sclerotic extension of anterior terminal apophysis); D, detail of A. E, male palpal embolic division, ventral. F, detail of C (arrow, embolus opening). G, apex of anterior terminal apophysis. H, detail of E. Abbreviations: ATA, anterior terminal apophysis; DSA, distal suprategular apophysis; E, embolus; LC1, anterior branch of lamella characteristica; LC2, median branch of lamella characteristica; LC3, posterior branch of lamella characteristica; MTA, median terminal apophysis; P, paracymbium; PBP, cymbial probasal process; PTA, posterior terminal apophysis; RLP, cymbial retrolateral process; STT, Solenysa tegular triangle. Scale bars in mm.

Figure 20. Solenysa wulingensis. A, male body, dorsal (left arrow, median pair tracheae extending into prosoma through petiole; right arrow, points to location of special glands). B–D, male prosoma. B, lateral; C, frontal; D, ventral. E, inner view of basal part of PLS showing special glands. F–H, spinnerets, F, male PLS and PMS; G, female PMS; H, female ALS and PLS. Abbreviations: AC, aciniform gland spigot(s); AG, aggregate gland spigot(s); ALS, anterior lateral spinneret; CY, cylindrical gland spigot(s); FL, flagelliform gland spigot(s); mAP, minor ampullate gland spigot(s); MAP, major ampullate gland spigot(s); PI, piriform gland spigot(s); PLS, posterior lateral spinneret; PMS, posterior median spinneret; SG, special gland. Scale bars in mm.

Figure 21. Solenysa wulingensis. A–B, male palp: A, retrolateral (arrow, paracymbial proximal curve); B, prolateral. C–D, male palpal embolic division: C, ventral; D, distal of C. E, anterior part of male abdomen showing smooth book lung cover. F, anterior part of male abdomen showing epiandrous fusules absent. G–H, epigynum: G, ventral; H, dorsal. Abbreviations: ATA, anterior terminal apophysis; CO, copulatory opening; DP, dorsal plate; DSA, distal suprategular apophysis; E, embolus; EC, epigynal collar; LC1, anterior branch of lamella characteristica; LC2, median branch of lamella characteristica; LC3, posterior branch of lamella characteristica; MS, macroseta; MT, median tooth on anterior terminal apophysis; MTA, median terminal apophysis; P, paracymbium; PBP, cymbial probasal process; PTA, posterior terminal apophysis; RLP, cymbial retrolateral process; SL, solenoid; STT, Solenysa tegular triangle. Scale bars in mm.

Figure 22. Distribution records of Solenysa species. Half-filled circle (), Solenysa retractilis sp. nov.; concentric circle (), Solenysa geumoensis Seo, 1996; circle filled with ‘i’ (), Solenysa wulingensis Li & Song, 1992; circle (•), Solenysa tianmushana sp. nov.; star (*), Solenysa protrudens Gao et al., 1993; cross (), Solenysa lanyuensis sp. nov.; flag (), Solenysa longqiensis Li & Song, 1992; balloon (), Solenysa yangmingshana sp. nov.; square (), Solenysa melloteei Simon, 1894; triangle (Δ), Solenysa akihisai sp. nov.; diamond (Ɨ), Solenysa partibilis Tu et al., 2007; pentagon (), Solenysa reflexilis Tu et al., 2007.