Gonatium absidatum Irfan, Zhang & Peng

Irfan, Muhammad, Zhou, Gu-Chun, Peng, Xian-Jin & Zhang, Zhi-Sheng, 2025, Survey of Linyphiidae spiders (Arachnida: Araneae) from some Oriental Regions of China, Megataxa 15 (1), pp. 1-248 : 61-64

Gonatium absidatum Irfan, Zhang & Peng , sp. n.

(Ƽŝiaee)

Figures 80–83 , 310

Types. Holotype ♂ ( HNU–GZ– IV–1407 ), CHINA, Guizhou Prov.: Maoxi, Wuluo Town, Fanjingshan NNR , 28.02256°N, 108.77995°E, 1277 m, 31.VII.2014, X.J. Peng et al. leg . Paratypes: 1♂ 6♀, with same data as for holotype ( HNU–GZ– IV–1407 ) ; 1♂, Taiping Town, Machahe River , Fanjingshan NNR , 27.88313°N, 108.78521°E, 597 m, 01.VIII.2014, X.J. Peng et al. leg. ( HNU–GZ– IV–1409 ) ; 2♂ 1♀, Taiping Town, Kema Vill. , Fanjingshan NNR , 27.84272°N, 108.77494°E, 540 m, 02.VIII.2014, X.J. Peng et al. leg. ( HNU–GZ– IV–1412 ) ; 1♂, Tongren City, Songtao Co., Wuluo Town , Taohuayuan Vill. , Fanjingshan NNR , 27.98810°N, 108.78313°E, 865 m, 05.XI.2017, T. Tian & D.Q. Li leg. ( HNU–GZ– IV–1711 ) .

Etymology. The specific epithet is derived from the Latin adjective “absidatus” meaning “arched” and referring to the arch-shaped tibial apophysis in male palp.

Diagnosis. Gonatium absidatum sp. n. resembles G. japonicum in having the similar hook-shaped paracymbium, long tibial apophysis extending above the apex of cymbium and the femur of tibia I & II with a row of stout ventral bristlesin male palp, the copulatory opening present anteriorly in epigyne,, with long internal copulatory ducts ( Figs 80A–D , 81A–D , 82A–D ; Millidge 1981, fig. 72, Oi 1960, figs 71, 72; Wang et al. 2015, figs 2i, 3i), but can be distinguished by retrograde basal tibial apophysis bifurcated and with 2 teeth at the base on the lateral margin of apophysis in dorsal view in G. absidatum sp. n. ( Figs 80B , 81E ; vs. not bifurcated and with 1 tooth); ectal part of spermathecae globular in G. absidatum sp. n. ( Fig. 82D ; vs. elliptical).

Description. Male (holotype, Figs 83A–C ): Total length: 2.21. Carapace 1.09 long, 0.89 wide, cephalic region elevated, clypeus and ocular area with hairs, orange with grey pattern, fovea, cervical and radial grooves distinct. Clypeus 0.49 high. Chelicerae with four promarginal and four retromarginal teeth. Sternum shield-like, as wide as long orange with greenish patches. Eyes: AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.05, ALE 0.08, PME 0.08, PLE 0.07 AME–AME 0.03, PME–PME 0.06,AME– ALE, 0.07, PME–PLE 0.08, AME–PME 0.05, ALE–ALE 0.37, PLE–PLE 0.41, ALE–PLE 0.02. Legs I–IV ventrally with row of thick spines. Length of legs: I 3.66 (1.03, 1.41, 0.77, 0.45), II 3.46 (1.01, 1.22, 0.81, 0.42), III 2.96 (0.87, 0.93, 0.75, 0.41), IV 3.66 (1.10, 1.15, 0.95, 0.46). Tibial spine formula: 1-1-1-1. TmI 0.27 and TmIV 0.24. Opisthosoma 1.32 long, 0.90 wide, cylindrical, dorsally light grey, with longitudinal grey band laterally, ventral side light grey.

Palp ( Figs 80A–D , 81A–D ): Femur cylindrical, as long as cymbium; patella three times longer than basal part of tibia, curved mesally. tibia with one retrolateral trichobothria, dorsally with C-shaped tibial apophysis (TBA), closely applied to dorsal side of cymbium, long, extending above the retrolateral margin of cymbium; retrograde basal tibial apophysis bifurcated and with two teeth at the base in dorsal view; cymbium unmodified, hoof-shaped; paracymbium (PC) simple, hook-shaped; tegulum (T) round with long membranous protegulum (PT); distal suprategular apophysis (DSA) membranous. Tailpiece (TP) spindle-shaped, slightly curved, with blunt tip; embolus (E) long, curved, accompanied by embolic membrane (EM) extending above the cymbium apex.

Female (one of paratypes, Figs 83D–F ): Total length: 2.51. Carapace 1.07 long, 0.95 wide, cephalic region slightly elevated, ocular region narrow, orange with grey pattern, fovea, cervical and radial grooves distinct. Clypeus 0.29 high. Chelicerae with 5 promarginal and 4 retromarginal teeth. Sternum shield-like, longer than wide, orange with microsetae. Eyes: AER recurved, PER straight, slightly wider than AER. Eye sizes and interdistances: AME 0.06 ALE 0.09, PME 0.07, PLE 0.07, AME–AME 0.06, PME–PME 0.04, AME–ALE, 0.03, PME–PLE 0.05, AME–PME 0.04, ALE–ALE 0.37, PLE–PLE 0.38, ALE–PLE 0.01. Length of legs: I 3.76 (1.07, 1.34, 0.88, 0.47), II 3.7 (1.04, 1.3, 0.89, 0.47), III 3.4 (0.95, 1.04, 0.79, 0.42), IV 4 (1.12, 1.32, 1.06, 0.5). Tibial spine formula: 1-1-1-1. TmI 0.27 and TmIV 0.18. Opisthosoma 1.52 long, 0.96 wide, oval, pale, dorsally with grey band.

Epigyne ( Figs 82A–D ): Epigynal plate wider than long; copulatory opening (CO) present anteriorly; copulatory ducts (CD) long, spirally coiled anteriorly; spermathecae (S) with mesal and ectal part, present laterally on dorsal plate, pointing away from each other; fertilization ducts (FD) short, extending mesally.

Distribution. Known only from the type localities (Guizhou Province, Fig. 310 ).

Figures

FIGURE 80. Gonatium absidatum sp. n., male holotype. A Palp, prolateral view; B Palp, retrolateral view; C Palp, ventral view; D Palp, dorsal view. Abbreviations: DSA—distal suprategular apophysis; E—embolus; EM—embolic membrane; PC— paracymbium; PT—protegulum; SPT—suprategulum; T—tegulum; TBA—tibial apophysis; TP—tailpiece.

FIGURE 81. Gonatium absidatum sp. n., male paratype palp. A Embolic division B Paracymbium C Suprategulum D tibial apophysis. Abbreviations: DSA—distal suprategular apophysis; E—embolus; EM—embolic membrane; PC—paracymbium; PT—protegulum; R—radix; SPT—suprategulum; TP—tailpiece.

FIGURE 82. Gonatium absidatum sp. n., female (one of paratypes). A–C Epigyne, ventral view; D Vulva, dorsal view. Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermathecae.

FIGURE 83. Gonatium absidatum sp. n., male (holotype, A–C), female (one of paratypes, D–F). A, D Habitus, dorsal view; B, E Habitus, lateral view; C, F Habitus, ventral view.

FIGURE 310. Distribution of Linyphiidae species in Guizhou Prov.: 1. Bathyphantes paracymbialis Tanasevitch, 2014; 2. Bifurcia ramosa (Li & Zhu, 1987); 3. Bolyphantes aculeatus sp. n.; 4. Bolyphantes arcuatus sp. n.; 5. Bolyphantes gladius sp. n.; 7. Dicristatus denticulatus sp. n.; 8. Diplocephalus tongrenensis sp. n.; 9. Diplocephaloides cucullus sp. n.; 10. Gonatium absidatum sp. n.; 11. Tapinocyba cornuta sp. n.; 12. Gongylidium demersum sp. n.; 13. Tapinocyba pingshanensis sp. n.; 14. Hylyphantes graminicola (Sundevall, 1830); 15. Nippononeta coreana (Paik, 1991); 16. Prosoponoides sinensis (Chen, 1991); 17. Ryojius fanjingshanensis sp. n.; 18. Ryojius fodingshanensis sp. n.; 19. Scotinotylus guizhouensis sp. n.; 20. Scotinotylus longiprojectus sp. n.; 21. Spelaeus cicatrix sp. n.; 6. Trematocephalus cristatus (Wider, 1834); 22. Walckenaeria asymmetrica Song & Li, 2011; 23. Walckenaeria xingdouensis sp. n..