Swilda S. Li & Lin, 2021

Li, Ya, Li, Shuqiang & Lin, Yucheng, 2021, Taxonomic study on fourteen symphytognathid species from Asia (Araneae, Symphytognathidae), ZooKeys 1072, pp. 1-47 : 1

Genus Swilda S. Li & Lin gen. nov.

Type species.

Crassignatha longtou Miller, Griswold & Yin, 2009, from Gaoligong Mountain, south-western China.

Etymology.

The generic name Swilda is derived from the Swild Studio (in Chinese: Xi Nan Shan Di Gong Zuo Shi). It is named after the organisation in honour of its dedication to promoting public advocacy for wildlife conservation and nature education in southwest China. The gender is masculine.

Diagnosis.

Swilda gen. nov. is easily distinguished from other symphytognathids, except Crassignatha , by having an anteromedially-split dorsal scutum in the male and a highly ornamented spinous and pitted carapace in both sexes (Figs 19A, D , 21A and D ). It resembles Crassignatha in carapace texture and the spherical spermathecae. The male differs from those of Crassignatha by having a conductor and lacking a cymbial tooth (Figs 20A and 22A ) vs. lacking a conductor, but having a cymbial tooth (figs 2A, 8A and 10A in Li et al. 2020); the female differs in lacking a scape and by the separated copulatory openings (Figs 20F and 22E ) vs. having a protruded scape and the adnate copulatory openings located at the apex of the scape in Crassignatha (figs 2G, 4G and 8G in Li et al. 2020).

Description.

Minute, body length 0.50-1.00. Carapace rounded or pyriform, strongly sclerotised, surface spinous and pitted (Figs 19A , 19D , 21A and 21D ). Cephalic part raised, higher in male than in female. Six eyes, white, in 3 diads. Clypeus high, more than 2 × diameter of ALE, concave. Chelicerae fused at middle, with 1 bifid tooth. Labium tongue-shaped, fused to coarse, pitted sternum. Sternum heart-shaped, slightly plump, truncated posteriorly (Figs 19B , 19E , 21B and 21E ). Male tibia II with one clasping spine (Figs 19B and 21B ). Abdomen globose in both sexes, male usually with a weakly sclerotised abdominal scutum split at mid-line (Figs 19A and 21A ), sclerotised annular plate encircles spinnerets (Figs 19B , 19E , 21B and 21E ). Colulus absent.

Pedicel orifice wide, wider than epigyne, with 2 pairs of lateral setae, posterior margin rebordered. Epigastric scutum distinctly sclerotised ventrally (not encircling pedicel).

Male palp (Figs 20A, B , 22A and B ): femur swollen, wider than patella, tibia lamellar. Bulb oblate; cymbium well developed, covers bulb on prolatero-ventral side, with 2 processes (CP1, CP2). Median apophysis present. Conductor longer than median apophysis, protruded out of bulb. Embolus long, tubular, sclerotised, originates at prolateral margin of tegulum, curved and extended beneath distal part of cymbium.

Epigyne (Figs 20C-F and 22C-E ): sclerotised, posterior margin slightly protruded. Parmula inconspicuous. Copulatory openings separated, located at posterior margin. Spermathecae globose, separated by less than 2 diameters. Copulatory ducts slender, twisted, encircling spermathecae, connected to anteromedial surface of spermathecae. Fertilisation ducts originate at posterolateral surface of spermathecae.

Composition.

Swilda longtou ( Miller et al, 2009) comb. nov. and S. spinathoraxi (Lin & Li, 2009) comb. nov.

Relationships.

Swilda gen. nov. is characterised by its tiny size, fused chelicerae at mid-line, AMEs and book lungs absent, female lacking palps and tarsi much longer than metatarsi. Here, the male of C. longtou is described for the first time and specimens of P. spinathoraxi are re-examined. We found the morphological features of these two species to be very similar to those of Crassignatha (see Li et al. 2020: 65), sharing the following combination of characters: a clasping spine on tibia II and an abdominal scutum latero-posteriorly in the male and a decorated carapace and sclerotised epigastric scutum in both sexes (Figs 19A-F and 21A-F ). The differences between these two species and Crassignatha are: a pitted and spinous carapace, a sclerotised annular plate that encircles the spinnerets (cf. Figs 19A-F and 21A-F vs. figs 1A-F and 7A-F in Li et al. 2020), only 1 male clasping spine (cf. Figs 19B and 21B vs. figs 1B and 12C in Li et al. 2020: only 1 spine in a few species), male palps lack a cymbial tooth, but have a conductor (cf. Figs 20A and 22A vs. figs 2A and 8A in Li et al. 2020) and the epigyne lacks a protruded scape (cf. Figs 20E-F and 22E-E vs. figs 2E and 6E in Li et al. 2020).

The genetic distance we estimated, based on COI, also indicated differences between these two species and members of other genera (see Appendix Table A1 ). Phylogenetic analysis of molecular data indicates that P. spinathoraxi and C. longtou are clearly congeneric. Additionally, the combined genetic evidence from five genes supports the monophyly of Swilda gen. nov. and the sister group relationship of the two genera (unpubl. data). Therefore, Swilda gen. nov. is proposed as a new genus in which to place S. longtou ( Miller et al, 2009) comb. nov., transferred from Crassignatha and S. spinathoraxi comb. nov., transferred from Patu . We designate Swilda longtou as the type species for this new genus.

Distribution.

China (Yunnan) (Fig. 23 ).

Figures

Figure 19. Swilda longtou A male habitus, dorsal B male habitus, ventral C male habitus, lateral D female habitus, dorsal E female habitus, ventral F female habitus, lateral. Abbreviation: TS = male clasping spines on tibia II. Scale bars: 0.50 (A-F).

Figure 20. Swilda longtou A male palp, prolateral B male palp, retrolateral C epigyne, ventral D epigyne, lateral E vulva, ventral F vulva, dorsal. Abbreviations: CA = cymbial apophysis; CD = copulatory ducts; Co = conductor; CO = copulatory opening; Cy = cymbium; CP 1 = proximal cymbial process; CP 2 = distal cymbial process; E = embolus; FD = fertilisation ducts; Fe = femur; MA = median apophysis; Pa = patella; S = spermathecae; T = tegulum; Ti = tibia. Scale bars: 0.10 (A-F).

Figure 21. Swilda spinathoraxi A male habitus, dorsal B male habitus, ventral C male habitus, lateral D female habitus, dorsal E female habitus, ventral F female habitus, lateral. Abbreviation: TS = male clasping spines on tibia II. Scale bars: 0.50 (A-F).

Figure 22. Swilda spinathoraxi A male palp, prolateral B male palp, retrolateral C epigyne, ventral D vulva, ventral E vulva, dorsal. Abbreviations: CA = cymbial apophysis; CD = copulatory ducts; Co = conductor; CO = copulatory opening; Cy = cymbium; CP 1 = proximal cymbial process; CP 2 = distal cymbial process; E = embolus; FD = fertilisation ducts; Fe = femur; MA = median apophysis; Pa = patella; S = spermathecae; T = tegulum; Ti = tibia. Scale bars: 0.10 (A-E).

Figure 23. Distribution records of fourteen species of genera Patu, Kirinua gen. nov. and Swilda gen. nov. in Asia 1 P. catba sp. nov. 2 P. dakou sp. nov. 3 P. damtao sp. nov. 4 P. jiangzhou sp. nov. 5 P. jidanweishi 6 P. nagarat sp. nov. 7 P. nigeri 8 P. putao sp. nov. 9 P. qiqi 10 P. xiaoxiao 11 K. maguai sp. nov. 12 K. yangshuo sp. nov. 13 S. longtou 14 S. spinathoraxi.