Spartaeus siloi, Ni & Yu & Zhang, 2025

Spartaeus siloi sp. nov.

Figs 3 View Figure 3 , 4 View Figure 4 , 5 Common name. 诗雷散蛛 View Figure 5

Type material.

Holotype: China • ♂ ( MHBU-ARA-00027416 ); Guangxi Zhuang Autonomous Region, Chongzuo City, Daxin County, Longdian ; 22.6931°N, 107.036975°E, 211 m elev.; 27. IV. 2024; W. Wang leg. GoogleMaps Paratypes: China • 1 ♀ ( MHBU-ARA-00027417 ); same data as holotype GoogleMaps ; 1 ♂ ( MHBU-ARA-00027538 ); Guangxi Zhuang Autonomous Region Autonomous Region, Chongzuo City, Daxin County, Xinkang ; 22.6538°N, 107.0755°E, 145 m elev.; 12. V. 2024; J. Zhang, K. Yu, Z. Yang, Y. Ni & Y. Li leg. GoogleMaps

Etymology.

The specific epithet is derived from “Si Loi”, which is a unique artistic style of Zhuang folk songs in Daxin County (the type locality). Noun in apposition.

Diagnosis.

The new species resembles S. platnicki Song, Chen & Gong, 1991 in the shape of the palpal bulb and copulatory duct, but it can be distinguished by the following: (1) the length of the embolus is much less than half of the bulb width (Figs 4 B View Figure 4 , 5 B View Figure 5 ; vs. in S. platnicki , the length of the embolus is more than half of bulb width; see Lin et al. 2023: fig. 18 A); (2) the end of the retrolateral tibial apophysis is relatively straight (Figs 4 B View Figure 4 , 5 B View Figure 5 ; vs. in S. platnicki , the end of the retrolateral tibial apophysis is strongly curved; see Lin et al. 2023: fig. 18 A); (3) the ventral intermediate tibial apophysis is rounded at the distal end in ventral view (Figs 4 B View Figure 4 , 5 B View Figure 5 ; vs. in S. platnicki , the ventral intermediate tibial apophysis is sharp at the distal end in ventral view; see Lin et al. 2023: fig. 18 A); and (4) the two copulatory ducts are nearly parallel (Figs 4 D View Figure 4 , 5 D View Figure 5 ; vs. curved posteriorly in S. platnicki ; see Lin et al. 2023: fig. 19 A).

Description.

Male. Measurements of holotype: total length 7.19. Carapace 3.42 long, 2.37 wide. Abdomen 3.58 long, 1.56 wide. Eye measurements: AME 0.81, ALE 0.45, PME 0.30, PLE 0.30. Leg measurements: I 15.55 (4.43, 1.28, 4.70, 3.7, 1.44), II 9.29 (2.30, 0.91, 2.61, 2.40, 1.07), III 10.05 (2.67, 0.89, 2.38, 2.53, 1.58), IV 13 (3.16, 1.07, 3.39, 4.19, 1.19); leg formula 1432. Chelicera (Fig. 3 D View Figure 3 ) dark brown, with seven promarginal and eight retromarginal teeth. Carapace (Fig. 3 B, C View Figure 3 ) yellow, margin and eye surroundings blackish-brown, anterior lateral margin deep black, eye field with black setae, eye surroundings covered by yellow and white setae, fovea dark and slit-like; endites and labium yellowish-brown, with black setae at distal end, endites slender. Legs (Fig. 3 B View Figure 3 ) with long and thin spines, coxa and trochanter off-white, femur to tibia with obvious grey stripes on anterior and posterior sides. Abdomen (Fig. 3 B View Figure 3 ) yellow, black strips interspersed with white setae around margins, broken near spinnerets; dorsal side with tawny patches and black setae; ventral side off-white, with white setae on both sides, center covered with greyish-white scales. Spinnerets (Fig. 3 B View Figure 3 ) white, spinnerets lateral inward white, lateral exterior with dark brown patches, covered with white setae.

Palp (Figs 4 A – C View Figure 4 , 5 A – C View Figure 5 ): embolus thin and short, sheep-horn-like in retrolateral view, base of embolus hidden behind membrane formed by distal haematodocha; tegular oval, surface smooth; tegular apophysis triangular, weakly sclerotized in ventral view; ventral tibial apophysis thick, triangular in ventral view; retrolateral tibial apophysis soft and movable, long and flat in ventral view, with small processes on distal end; dorsal intermediate tibial apophysis blackish-brown, with snake-scale-like processes on outer surface, edge wide and flat; ventral intermediate tibial apophysis yellowish-brown, rounded at distal end in ventral view; distal end of cymbium with grey hair tuft.

Female. Measurements of paratype: total length 6.55. Carapace 2.92 long, 2.31 wide. Abdomen 3.33 long, 2.07 wide. Eye measurements: AME 0.68, ALE 0.40, PME 0.28, PLE 0.39. Leg measurements: I 9.15 (2.72, 1.03, 2.70, 1.84, 0.86), II 7.16 (2.25, 0.76, 1.88, 1.53, 0.74), III 7.45 (2.19, 074, 1.84, 1.83, 0.85), IV 8.68 (2.85, 0.72, 2.67, 1.52, 0.92); leg formula 1432. Chelicera (Fig. 3 F View Figure 3 ) brown, with six promarginal and eight retromarginal teeth. Habitus (Fig. 3 A, E View Figure 3 ) similar to that of male, but different in: carapace paler at margin forming a black band from anterior lateral eyes to rear edge of carapace; with a black band in lower position between the anterior median eyes and the posterior lateral eyes; black strips on lateral dorsal side of abdomen not continuous, but with intermittent small black bands.

Epigyne (Figs 4 D, E View Figure 4 , 5 D, E View Figure 5 ): epigynal plate oval, slightly raised in a mound-like shape; copulatory openings small, slit-shaped in ventral view, anteriorly located; copulatory ducts extending to posterior part, dark and slender; spermathecae reddish-brown, large and kidney-shaped; fertilization ducts short, connecting with spermathecae at posterior part; accessory glands located centrally at inner margins of spermathecae, partly hidden by spermathecae in dorsal view.

Distribution.

China (Guangxi).

Comments.

Following a previous study on Spartaeus ( Yang et al. 2017: figs 4, 8, 10), we labelled the weekly sclerotized apophysis derived from the tegulum of male palpal bulb as TA. This structure was identified as M 3 in Wanless (1984). Additionally, the membranous patch of the distal haematodocha at the base of embolus is referred to here as M, aligning with the designation of M 1 in Wanless’s (1984) study on Spartaeus . In the redescription of S. platnicki Song, Chen & Gong, 1991 , the marked TA ( Lin et al. 2023: fig. 18) is likely mislabelled and probably should be M in this study, considering its position at the base of embolus.