Sinoalaria xiaotu Yu & Lin, 2023

Zhang, Jianshuang, Feng, Chengcheng, Yu, Hao & Lin, Yucheng, 2023, A review of the spider genus Sinoalaria (Araneae, Theridiosomatidae), with the descriptions of four new species and two new combinations, ZooKeys 1173, pp. 307-338 : 307

Sinoalaria xiaotu Yu & Lin sp. nov.

Figs 15 , 16 , 17

Type material.

Holotype ♂ and Paratypes 6♀, Vietnam: Bac Can, Barbie National Park, Beilan cave, 22°22.766'N, 105°36.790'E, 280 m, 2.IV.2012, Z. Yao leg.; 1♂ 6♀, same data as holotype, 18.X.2012, H. Zhao and Z. Chen leg.

Other material examined.

1♂ 2♀, Vietnam: Phu Tho, Xuan Son National Park, Lun Cave , 21°07.022'N, 104°57.443'E, 398 m, 26.X.2012, H. Zhao and Z. Chen leg.

Etymology.

The specific name is derived from the Chinese pinyin 'xiǎo tū’, which means 'small apophysis’, referring to the small median apophysis which is no more than 1/3 of tegulum length; noun in apposition.

Diagnosis.

Males of S. xiaotu sp. nov. can be distinguished from congeners except S. bicornis by the similar indistinct embolic base and the small median apophysis which is no more than 1/2 of tegulum length (Figs 1A, B , 15A-C ) (embolic bases prominently visible, large median apophysis longer than 1/2 of tegulum length in all other Sinoalaria species, including S. chengguanensis and S. chi sp. nov., etc.; Figs 5 , 7 ), but differ from the latter by the: (1) median apophysis extremely small, no more than 1/3 of tegulum length, both proximal process and distal process are indistinct in S. xiaotu sp. nov. (median apophysis relatively larger, ca 1/2 of tegulum length, proximal process finger-like, distal process hook-shaped in S. bicornis ) (cf. Fig. 15A-C and Fig. 1A ); (2) cymbium basally with a cluster of six setae in S. xiaotu sp. nov. (with a cluster of eight setae in S. bicornis ) (cf. Fig. 15D and Fig. 1B ); (3) the apex of conductor needle-shaped, sharp in S. xiaotu sp. nov. (nearly triangular, relatively blunt in S. bicornis ) (cf. Fig. 15C and Fig. 1A ). Females of this species can be distinguished from all other congeners by the heavily sclerotized and dumbbell-shaped scape (Fig. 16E, F ).

Description.

Male (holotype) (Fig. 16A, B ): Carapace nearly pyriform, yellowish white, with a wide U-shaped paramedian stripe starting from behind PLE, almost reaching the posterior margin of carapace; paramedian stripe centrally dark, marginally lighter. Anterior eye row distinctly recurved, posterior eye row almost straight in dorsal view. Sternum heart-shaped, centrally yellowish with sparse setae, marginally dark. Mouthparts yellowish brown. Legs uniformly yellowish white. Abdomen oval, clothed with dense setae. Dorsum of abdomen basically yellowish brown, with four pair of black spots: 1st pair oval and separated by ca 1.5 × width; 2nd pair nearly fan-shaped, widely separated by ca 3 × width; 3rd pair and 4th pair fused, represented by a pattern which is shaped like ‘][’. Venter of abdomen yellowish white, centrally with a pentagon-shaped black speckle. Measurements: Total length 1.8. Carapace 1.0 long, 0.8 wide. Clypeus 0.1 high. Sternum 0.5 long, 0.4 wide. Abdomen 1.2 long, 1.1 wide. Length of legs: I 3.6 (1.2, 0.4, 1.0, 0.6, 0.4); II 3.2 (1.0, 0.4, 0.9, 0.6, 0.3); III 2.3 (0.6, 0.3, 0.6, 0.5, 0.3); IV 2.8 (0.7, 0.3, 0.7, 0.7, 0.4).

Palp (Fig. 15A-D ): Tibia small, cup-shaped, ca 1/5-1/4 length of cymbium, with several short and sparse setae. Retrolateral tibial apophysis small, ca 1/4-1/3 length of tibia, nearly triangular, apex blunt. Cymbium narrow, ca 2.2 × longer than wide, dorsally bears several long and sparse setae; basally with a cluster of six setae, the setae conspicuous and almost 1/2 of cymbial length. Paracymbium blade-shaped, ca 1/6-1/5 length of cymbium, apex acute. Tegulum broad, oval, 1.4 × longer than wide, central surface with reticular grooves, marginally smooth; sperm duct distinct. Median apophysis small, ≤ 1/3 of tegulum length, with a papilliform proximal process and a digitiform distal process, both processes are indistinct. Embolus filiform, in retrolateral view, arising at approximately the 4-5 o’clock position, extending behind tegulum, terminating at ca 10 o’clock position, embolic base indistinct. Conductor tubular and relatively sclerotized, thick except needle-shaped apex.

Female (one paratype). Somatic features as in Fig. 16C, D and coloration slightly darker than in male. Measurements: Total length 2.2. Carapace 1.0 long, 0.7 wide. Clypeus 0.1 high. Sternum 0.5 long, 0.4 wide. Abdomen 1.4 long, 1.1 wide. Length of legs: I 3.4 (1.0, 0.3, 0.8, 0.9, 0.4); II 2.4 (0.7, 0.3, 0.5, 0.6, 0.3); III 1.9 (0.5, 0.2, 0.4, 0.5, 0.3); IV 2.7 (0.9, 0.3, 0.6, 0.6, 0.3).

Epigyne (Fig. 16E-G ). Epigynal plate slightly wider than long, the arrangement of the various parts of the vulva obscured through epigynal plate before dissection. Scape long, heavily sclerotized, surface smooth; proximal part fuse to ventral plate of epigyne, originating from posterior portion of the plate, extending posteriorly, ca 1.3 × length of the plate; proximally widest, then gradually narrowing distally, finally widening at apex, shaped like a dumbbell-shaped. Copulatory ducts coils located anterolaterally to spermathecae: ventral and anterior folds represented by two large bursae, bursae surface hyaline and egg-shaped; almost all part of dorsal and posterior folds covered by posterior part of spermathecae. Spermathecae nearly globular, strongly sclerotized, located centrally and juxtaposed, overlapping with dorsally postero-interior part of copulatory ducts; spermathecal diameter ca 1/3 length of epigyne plate, the two spermathecae closely spaced. Fertilization ducts short, acicular, membranous, located on posterior surface of spermathecae; apical parts separated by approximately the length of fertilization duct, apex sharp.

Distribution.

Known only from Barbie National Park and Xuan Song National Park in Vietnam (Fig. 17 ).

Figures

Figure 1. Male palp of Sinoalaria bicornis (Lin, Li & Jaeger, 2014) A prolateral view B retrolateral view C dorsal view D ventral view. Abbreviations: Co = conductor; Cy = cymbium; EB = embolic base; Em = embolus; MA = median apophysis; Pc = paracymbium; RTA = retrolateral tibial apophysis; SCy = setae on cymbium; Te = tegulum. Scale bars: 0.20 mm.

Figure 5. Male palp of Sinoalaria chengguanensis (Zhao & Li, 2012) A prolateral view B retrolateral view C embolic division, dorsal view D ventral view. Abbreviations: Co = conductor; Cy = cymbium; EB = embolic base; Em = embolus; MA = median apophysis; Pc = paracymbium; RTA = retrolateral tibial apophysis; SCy = setae on cymbium; Te = tegulum. Scale bars: 0.20 mm.

Figure 7. Male palp of the holotype of Sinoalaria chi sp. nov. A prolateral view B retrolateral view C ventral view D dorsal view. Abbreviations: Co = conductor; Cy = cymbium; EB = embolic base; Em = embolus; MA = median apophysis; Pc = paracymbium; RTA = retrolateral tibial apophysis; Te = tegulum. Scale bars: 0.20 mm.

Figure 15. Male palp of the holotype of Sinoalaria xiaotu sp. nov. A prolateral view B retrolateral view C ventral view D dorsal view. Abbreviations: Co = conductor; Cy = cymbium; EB = embolic base; Em = embolus; MA = median apophysis; Pc = paracymbium; RTA = retrolateral tibial apophysis; SCy = setae on cymbium; Te = tegulum. Scale bars: 0.20 mm.

Figure 16. Sinoalaria xiaotu sp. nov., female paratype and male holotype, male habitus (A, B), female habitus (C, D) and epigyne (E-G) A dorsal view B ventral view C dorsal view D ventral view E intact, ventral view F cleared, ventral view G cleared, dorsal view. Abbreviations: CD = copulatory duct; DPF = dorsal and posterior fold of copulatory duct; FD = fertilization duct; Sc = scape; Sp = spermatheca; VAF = ventral and anterior fold of copulatory duct. Scale bars: 0.50 mm (A-D); 0.20 mm (E-G).

Figure 17. Distribution records of the species from genus Sinoalaria.