Ischnothyreus an Tong & Li

Tong, Yanfeng, Koh, Joseph K. H., Tong, Xiujiao & Li, Shuqiang, 2016, Five new species of the genus Ischnothyreus Simon, 1893 from Singapore, ZooKeys 618, pp. 39-66 : 41

Taxon classification Animalia Araneae Oonopidae

Ischnothyreus an Tong & Li sp. n. Figs 1, 2, 3

Type material.

Holotype: male (LKCNHM), Singapore: Central Catchment Nature Reserve, Alt. 60 m, 1°21'21.7"N, 103°48'3.8"E, August 26, 2015, S. Li and Y. Tong leg. Paratypes: 1 male, 5 females (LKCNHM), same data as holotype.

Other material studied.

4 females (SYNU-60), Singapore: Central Catchment Nature Reserve, near Mandai Agrotechnology Park, Alt. 46 m, 1°24'53.7"N, 103°47'56.2"E, Sep 1, 2015, S. Li and Y. Tong leg.; 8 females (SYNU-61), Singapore: Central Catchment Nature Reserve, Alt. 46 m, 1°21'13.3"N, 103°48'29.4"E, August 27, 2015, S. Li and Y. Tong leg.; 6 males, 6 females (SYNU-62), Singapore: Central Catchment Nature Reserve, treetop walk, 1°21'13.3"N, 103°48'29.4"E, August 28, 2015, S. Li and Y. Tong leg.; 1 male, 1 female (SYNU-63), Singapore: Central Catchment Nature Reserve, Alt. 39 m, 1°21'17.9"N, 103°47'50.7"E, August 25, 2015, S. Li and Y. Tong leg.; 2 males, 1 female (SYNU-64), Singapore: Central Catchment Nature Reserve, Alt. 39 m, 1°21'17.9"N, 103°47'50.7"E, August 25, 2015, S. Li and Y. Tong leg.

Etymology.

The species's name is derived from the Chinese Pinyin "an", meaning dark, which refers to the color of the palp; term in apposition.

Diagnosis.

The new species is similar to Ischnothyreus tekek Kranz-Baltensperger, 2012 in having similar thorn-like protrusion (tlp) on the proximal part of the paturon (Figs 1G, H, 3G and Kranz-Baltensperger 2012: fig. 3D) in male, but can be distinguished from it by the finger-shaped sclerotized process (fsp) at base of fangs (Fig. 3H) in male, and the triangular shaped atrium (tsa) in the female epigastric region (Fig. 2 G–J)

Description.

Male (holotype). Total length 1.18; carapace 0.65 length, 0.48 width; abdomen 0.57 length, 0.34 width. Habitus as in Fig. 1A, C, E. Carapace: pale orange, with brown, egg-shaped patches behind eyes, ovoid in dorsal view, strongly elevated in lateral view, surface of elevated portion of pars cephalica smooth, sides finely reticulate, fovea absent, lateral margin straight, smooth (Fig. 1B, D). Clypeus: straight in frontal view, vertical in lateral view, ALE separated from edge of carapace by their radius or more. Eyes: six, well developed, ALE largest, ALE circular, PME and PLE oval, posterior eye row procurved from both above and front, ALE separated by less than their radius, ALE-PLE separated by less than ALE radius, PME touching, PLE-PME touching (Fig. 1I). Sternum: longer than wide, pale orange, uniform, not fused to carapace, surface smooth, setae sparse. Mouthparts: chelicerae, endites and labium orange. Chelicerae straight, with finger-shaped sclerotized process (fsp) at base of fangs (Fig. 3H), proximal part of paturon with a thorn-like protrusion (tlp) (Figs 1G, H, 3G), fang groove with a few small and two larger denticles. Labium rectangular, fused to sternum, anterior margin not indented at middle. Anteromedian tip of endites with one strong, tooth-like projection (Fig. 1E, F). Abdomen: ovoid, rounded posteriorly. Posterior spiracles not connected by groove. Pedicel tube short, ribbed, scutum not extending far dorsal of pedicel. Dorsal scutum well sclerotized, pale orange, covering whole abdomen width and approximately 4/5 of abdomen length, fused to epigastric scutum, middle surface and sides smooth. Epigastric and postepigastric scutum well sclerotized, pale orange, fused, without posteriorly directed lateral apodemes. Dorsum setae present, light, needle-like. Legs: pale orange, femur I with two prolateral and two small retrolateral spines, tibia I with four pairs, metatarsus I with two pairs of long ventral spines. Leg II spination is similar to leg I except femur with only one prolateral and one retrolateral spine. Legs III and IV spineless. Genitalia: epigastric region with sperm pore middle sized, circular, situated at level of anterior spiracles. Palp strongly sclerotized, right and left palps symmetrical, trochanter with ventral projection (vp) (Fig. 3A, D), cymbium brown, fused with bulb, bulb brown, more than two times as long as cymbium, tapering apically, with two small ventral protuberances (vpr) (Fig. 3D), distal part elongated, with membranous leaf-shaped apophyses (lsa) (Fig. 3B, C, E, F).

Female (paratype). Total length 1.37; carapace 0.64 length, 0.51 width; abdomen 0.76 length, 0.53 width. Habitus as in Fig. 2A, C, E. As in male except as noted. Carapace: without any pattern. Mouthparts: chelicerae and endites unmodified. Abdomen: dorsal scutum covering less than 1/2 of abdomen length, less than 1/3 of abdomen width. Postepigastric scutum rectangular. Genitalia: the posterior margin of the epigastric scutum is lined with numerous needle-like setae. The epigastric groove is narrow. From the middle of the slightly thickened margin of the postepigastric scutum runs a dark, winding tube posteriorly (wt) (Fig. 2G, I), ending in an equilateral triangular shaped atrium (tsa) (Fig. 2H, J).

Distribution.

Singapore.