Sinoalaria chi 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 chi Yu & Lin sp. nov.

Figs 7 , 8 , 17

Type material.

Holotype ♂ and Paratype 1♀, Vietnam: Hang Dai Ca, 20°33.520'N, 105°53.287'E, 30.XII.2013, H. Sterner leg.

Other material examined.

Vietnam. 1♂ 2♀, Hang Boi , 20°15.533'N, 105°53.278'E, 24-25.XII.2013, H. Steiner leg. ; 1♂ 5♀, Hang Tra Tu , 20°06.492'N, 105°55.040'E, 28.XII.2013, H. Steiner leg.

Etymology.

The specific name is derived from the Chinese pinyin ‘chǐ’, which means ‘tooth’, referring to the tooth-shaped lower ramus on distal process of median apophysis; noun in apposition.

Diagnosis.

Males of S. chi sp. nov. resemble those of S. cavernicola . The two species share a similarly slender and filiform embolus, sheet-shaped paracymbium with a spine-like tip, and the median apophysis with serrated proximal process and slightly bifurcated distal process but differ by: (1) distal process of median apophysis short and wide, slightly shorter and narrower than the base of median apophysis in S. chi sp. nov. (long and narrow, slightly longer and distinctly narrower than base in S. cavernicola ) (cf. Fig. 7A and Fig. 3A ); (2) the lower ramus on distal process of median apophysis tooth-shaped, apex sharp, distinctly longer than the indistinct upper ramus in S. chi sp. nov. (both rami distinct, are of equal length, the lower one with a relatively blunt tip in S. cavernicola ) (cf. Fig. 7A and Fig. 3A ); (3) embolus distinctly longer, terminating at ca 8 o’clock position in retrolateral view, terminating at ca 4 o’clock position in ventral view in S. chi sp. nov. (terminating at ca 10 o’clock position both in retrolateral and ventral view in S. cavernicola ) (cf. Fig. 7A, C and Fig. 3A, C ); (4) embolic base relatively smaller, its width ca 1/2 of tegulum length in S. chi sp. nov. (embolic base wider than 2/3 of tegulum length in S. cavernicola ) (cf. Fig. 7B and Fig. 3B ). Females also resemble those of S. cavernicola in having a completely membranous, rugose scape which distally with a pocket-like hood (the combination of these features are absent in all other congeners), and the general shape of the endogyne but can be distinguished from the latter by the ventral and anterior folds of copulatory ducts represented by two oblong bursae, the dorsal and posterior folds represented by a longitudinal loop and a horizontal loop in S. chi sp. nov. (ventral and anterior folds represented by two more or less globular bursae, dorsal and posterior folds running horizontally, forming only one loop in S. cavernicola ) (cf. Fig. 8G and Fig. 4G ).

Description.

Male (holotype) (Fig. 8A, B ): Carapace shaped like a water drop, brown, darker in the front, without distinct pattern; pars cephalica distinctly narrowed, cervical groove and radial grooves faint. Anterior eye row distinctly recurved, posterior eye row slightly procurved. Sternum shield-shaped, dark. Mouthparts reddish brown. Legs uniformly yellowish, femora slightly darker. Abdomen round, dorsum basically black, with a lengthwise yellowish median stripe extending almost of whole abdomen length, gradually narrow posteriorly, with three pairs of yellowish speckles on either side; venter black centrally, yellowish marginally. Measurements: Total length 2.4. Carapace 1.1 long, 0.8 wide. Clypeus 0.1 high. Sternum 0.5 long, 0.4 wide. Abdomen 1.1 long, 1.1 wide. Length of legs: I 3.1 (1.1, 0.3, 0.7, 0.6, 0.4); II 2.3 (0.7, 0.3, 0.5, 0.5, 0.3); III 1.7 (0.5, 0.2, 0.5, 0.3, 0.2); IV 2.3 (0.8, 0.3, 0.6, 0.4, 0.2).

Palp (Fig. 7A-D ): Tibia small, cup-shaped, ca 1/3 length of cymbium. Retrolateral tibial apophysis small but distinct, thumb-like, ca 1/3-1/2 length of tibia. Cymbium narrow, ca 2.3 × longer than wide, dorsally bears several long and sparse setae, basally without tufty setae. Paracymbium ca 1/8-1/7 length of cymbium, represented by a small sheet, distally bears a needle-shaped spine. Tegulum capacious, oval, 1.3 × longer than wide; sperm duct distinct. Median apophysis large, located prolaterally to tegulum, consisting of a broad base and two process; proximal process ca 2/3 length of base, distally serrated; distal process wide, slightly shorter than base, distally slightly bifurcated, upper ramus indistinct, lower ramus tooth-shaped. Embolic base large, represented by enlarged tubercle, located at the 9-10 o’clock position to tegulum in retrolateral view, its width ca 1/2 tegulum length. The free part of embolus long and slender, filiform, in retrolateral view, arising at approximately the 8-9 o’clock position, forming a loop, terminating at ca 8 o’clock position, its tip curved behind embolic base. Conductor tubular and translucent, enveloping the second half of embolus, apex pointing retrolaterally.

Female (paratype). Somatic features as in Fig. 8C, D and coloration distinctly darker than in male. Measurements: Total length 3.2. Carapace 1.5 long, 1.1 wide. Clypeus 0.1 high. Sternum 1.1 long, 0.9 wide. Abdomen 2.1 long, 1.6 wide. Length of legs: I 4.4 (1.4, 0.4, 1.1, 1.0, 0.5); II 3.5 (1.1, 0.4, 0.9, 0.7, 0.4); III 2.4 (0.6, 0.3, 0.6, 0.5, 0.3); IV 3.2 (1.0, 0.3, 0.8, 0.7, 0.4).

Epigyne (Fig. 8C-E ). Epigynal plate large, distinctly wider than long, the arrangement of the various parts of the vulva are faint through the tegument. Scape long, rugose, translucent, extending from posterior margin of epigynal plate, ca 1.8 × plate length; apex blunt and slightly sclerotized, represented by a small pocket-like hood. Copulatory ducts strongly convoluted, located laterally to spermathecae: ventral and anterior folds of copulatory ducts represented by two oblong bursae, bursae surface membranous, ca 2/3 length of epigyne plate, the two bursae separated by ca 1.7 × their widths; dorsal posterior folds tubular, heavily sclerotized and strongly convoluted, forming a longitudinal loop and a horizontal loop, finally connecting with ventral surface of spermathecae. Spermathecae bean-shaped, strongly sclerotized, ca 1/2 length of epigyne plate, 2 × longer than wide, located centrally and juxtaposed, the two spermathecae closely spaced. Fertilization ducts short, ribbon-shaped, membranous, located on dorsal-basal surface of spermathecae; apical parts separated by ca 1.5 × fertilization duct length, apex curved and sharp.

Distribution.

Northern Vietnam (Fig. 17 ).

Figures

Figure 3. Male palp of Sinoalaria cavernicola (Lin, Li & Jaeger, 2014) 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 4. Sinoalaria cavernicola (Lin, Li & Jaeger, 2014), 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 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 8. Sinoalaria chi 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.