Gongylidium demersum 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 : 77-78

Gongylidium demersum Irfan, Zhang & Peng , sp. n.

(Sê圆ae)

Figures 96 , 97 , 310

Types. Holotype ♀ ( HNU–GZ– IV–1706 ), CHINA, Guizhou Prov.: Tongren City, Shiqian Co., Pingshan Town , Fodingshan Vill ., Fodingshan NNR , 27.34899°N, 108.16272°E, 666 m, 01.XI.2017, G.C. Zhou leg. Paratype: 1♀, With same data as for holotype female ( HNU–GZ– IV–1706 ).

Etymology. The specific epithet is derived from the Latin adjective "demersus" meaning "depressed" referring to the slightly depressed posterior margin of dorsal plate in epigyne.

Diagnosis. Gongylidium demersum sp. n. resembles G. minutum sp. n. in having the similar dorsal plate ( Figs 96A–C ; Figs 98A–C ), and can be distinguished by the ventral plate without any hood in G. demersum sp. n. ( Figs 96A, B ), vs. hood present in G. minutum sp. n. ( Figs 98A, B ); copulatory ducts short, not forming loop before entering the spermathecae in G. demersum sp. n. ( Fig. 96C ), vs. sinuous, forming long loop before entering the spermathecae in G. minutum sp. n. ( Figs 98B, C ).

Description. Female ( Figs 97A, B ): Total length: 2.06. Carapace 0.93long, 0.67 wide, cephalic region slightly elevated, pale, mid dorsally with macrosetae, cervical and radial grooves distinct. Clypeus 0.19 high. Chelicerae with five promarginal and five retromarginal teeth. Sternum longer than wide, light greenish with grey patches and microsetae. Eyes: AER recurved, PER procurved, slightly wider than AER. Eye sizes and interdistances: AME 0.04, ALE 0.04, PME 0.05, PLE 0.05, AME–AME 0.01, PME–PME 0.02, AME–ALE, 0.04, PME–PLE 0.04, AME–PME 0.04, ALE–ALE 0.22, PLE–PLE 0.23, ALE–PLE contiguous. Length of legs: I 2.17 (0.65, 0.75, 0.41, 0.36), II 1.92 (0.61, 0.60, 0.37, 0.34), III 1.67 (0.54, 0.52, 0.32, 0.29), IV 2.17 (0.65, 0.79, 0.41, 0.32). TmI 0.27 and TmIV 0.16. Tibial spine formula: 2-2-1-1. Opisthosoma 1.15 long, 0.64 wide, oval, pale, densely covered with fine macrosetae.

Epigyne ( Figs 96A–C ):Ventral plate (VP) sclerotized, wider than long; dorsal plate (DP) rectangular, posterior margin slightly concave; copulatory opening (CO) present at the junction of dorsal and ventral plate; copulatory ducts (CO) short; spermathecae (S) elliptical, present at the apex of dorsal plate anteriorly; fertilization ducts (FD) extending mesally.

Male. Unknown.

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

Figures

FIGURE 96. Gongylidium demersum sp. n., female holotype. A, B Epigyne, ventral view; C Vulva, dorsal view. Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermatheca; VP—ventral plate.

FIGURE 97. Gongylidium demersum sp. n., female holotype. A Habitus, dorsal view; B Habitus, ventral view.

FIGURE 98. Gongylidium minutum sp. n., female holotype. A, B Epigyne, ventral view; C Vulva, dorsal view. Abbreviations: CD—copulatory duct; CO—copulatory opening; DP—dorsal plate; FD—fertilization duct; S—spermatheca; VP—ventral plate.

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..