Ischnothyreus sijiae Tong & Li, 2021

Tong, Yanfeng, Sun, Xiaochen, Li, Shuqiang & Bian, Dongju, 2021, Taxonomic study of the genus Ischnothyreus (Araneae, Oonopidae) from Xishuangbanna Rainforest, southwestern China, ZooKeys 1034, pp. 165-197 : 165

Ischnothyreus sijiae Tong & Li sp. nov. Figures 16 , 24A, B

Type material.

Holotype ♀: China, Yunnan, Xishuangbanna Tropical Garden; 21°54.999'N, 101°16.237'E; 561 m; 24.IV.2019; Y. Tong and J. Liu leg. (SYNU-426). Paratype. 1♀: same data as for holotype (SYNU-427).

Diagnosis.

The new species is similar to I. tadfane Tong & Li, 2013 in the large dorsal scutum of the abdomen, but can be distinguished by the greater short winding tube of the endogyne (Fig. 24B ) (vs long winding tube; Tong and Li 2013: fig. 4I, K) and the nipple-shaped atrium (Fig. 24A ) (vs inverted bell shaped atrium; Tong and Li 2013: fig. 4H, J).

Description.

Female (holotype). Body: habitus as in Fig. 16A-C ; body length 1.49. Carapace: 0.68 long, 0.54 wide; yellow-brown, without any pattern, surface finely reticulate, lateral margin straight, smooth (Fig. 16D, E ). Clypeus: height about 0.8 times ALE diameter (Fig. 16G ). Eyes: see Fig. 16D, G . Sternum: pale orange (Fig. 16F ). Mouthparts: chelicerae, endites and labium orange; chelicerae straight, base of fangs unmodified (Fig. 16G ); endites unmodified (Fig. 16F ). Abdomen: 0.86 long, 0.53 wide; dorsal scutum well sclerotized, brown, covering 2/3 of the abdomen width and approximately 4/5 of the abdomen length, not fused to epigastric scutum; epigastric and postgastric scutum well sclerotized, pale orange, unfused (Fig. 16A-C ). Legs: pale orange, femur I with 2 prolateral spines, tibia I with 4 pairs, metatarsus I with 2 pairs of long ventral spines. Leg II spination similar to leg I except femur with only 1 prolateral spine. Legs III and IV spineless. Epigastric area: surface without external features (Fig. 16H ). Endogyne: from the middle of the slightly thickened margin of the postgastric scutum runs a dark, simple winding tube, ending in a small nipple-shaped atrium (Fig. 24A, B ).

Male. Unknown.

Etymology.

The species is named after Miss Sijia Liu, one of the collectors of the holotype.

Comment.

Among the known species of the genus Ischnothyreus of China, I. qianlongae Tong & Li, 2008 and I. tergemintus Liu, Xu & Henrard, 2019 are known only from males. I. sijiae sp. nov. can be distinguished from I. tergemintus by the brown colour on the abdomen and sides of carapace (vs yellow abdomen and carapace in I. tergemintus ; Liu et al. 2019: fig. 1A); and from I. qianlongae by the smaller size of the eyes (compare Fig. 16D with Tong and Li (2008: fig. 4A)).

Distribution.

Known only from the type locality.

Figures

Figure 16. Ischnothyreus sijiae sp. nov., female paratype A-C habitus, dorsal, lateral and ventral views D-G prosoma, dorsal, lateral, ventral and anterior views H epigastric region, ventral view. Scale bars: 0.4 mm (A-G); 0.2 mm (H).

Figure 24. Endogyne of Ischnothyreus spp., A, B I. sijiae sp. nov. C, D I. xiaolongha sp. nov. A, C ventral view B, D dorsal view. Abbreviations: a = apodemes; bsa = bell-shaped atrium; nsa = nipple-shaped atrium; wt = winding tube. Scale bars: 0.2 mm.