Ischnothyreus poculum 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 : 45-47

Taxon classification Animalia Araneae Oonopidae

Ischnothyreus poculum Tong & Li sp. n. Figs 10, 11, 12

Type material.

Holotype: male (LKCNHM), Singapore: Central Catchment Nature Reserve, near Singapore Zoo, Alt. 50 m, 1°24'22.3"N, 103°47'7.4"E, August 30, 2015, S. Li and Y. Tong leg. Paratypes: 1 female (LKCNHM), same data as holotype; 1 female (LKCNHM), Singapore: Bukit Timah Nature Reserve, Alt. 86 m, 1°21'37.4"N, 103°46'30.0"E, August 24, 2015, S. Li and Y. Tong leg.

Other material studied.

2 females (SYNU-71), 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.; 1 female (SYNU-72), 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.

Etymology.

The specific epithet means “bowl” in Latin, and refers to the bowl-shaped atrium in the female epigastric region; noun.

Diagnosis.

The new species is similar to Ischnothyreus campanaceus Tong & Li, 2008, but can be distinguished from it by the small abdominal dorsal scutum, the long sclerotized process (lsp) and small sclerotized triangular-shaped apophysis (sta) at base of fangs in male (Fig. 10H), and the bowl-shaped atrium in the female epigastric region (Fig. 11 G–K). Males of the new species is also similar to those of Ischnothyreus jojo Kranz-Baltensperger, 2011 by the long sclerotized process (lsp) on the cheliceral fang (Figs 10G, H, 12G), but can be distinguished from it by the small sclerotized triangular-shaped apophysis (sta) at base of fangs (Fig. 10H) and the membranous outgrowth on distal part of male palp (Fig. 12 A–E).

Description.

Male (holotype). Total length 1.64; carapace 0.83 length, 0.67 width; abdomen 0.80 length, 0.46 width. Habitus as in Fig. 10A, 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. 10B, 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 straight from above, procurved from front, ALE separated by less than their radius, ALE-PLE separated by less than ALE radius, PME touching, PLE-PME touching (Fig. 10I). Sternum: longer than wide, pale orange, uniform, not fused to carapace, surface smooth, setae sparse. Mouthparts: chelicerae, endites and labium orange. Chelicerae straight, with long sclerotized process (lsp) and small sclerotized triangular-shaped apophysis (sta) at base of fangs (Fig. 12G, H), fang groove with a few small and one larger denticles. Labium rectangular, fused to sternum, anterior margin not indented at middle. Anteromedian tip of endites with one strong, tooth-like projection (Fig. 10E, F). Abdomen: ovoid, rounded posteriorly. Posterior spiracles not connected by groove. Pedicel tube short, ribbed, scutum not extending far dorsal of pedicel. Dorsal scutum weakly sclerotized, pale orange, covering approximately 1/2 of abdomen length, 1/2 of abdomen width, fused to epigastric scutum. Epigastric and postepigastric scutum weakly 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. 12C, D), cymbium brown, fused with bulb, bulb brown, more than two times as long as cymbium, tapering apically, with two ventral protuberances (vpr) (Fig. 12B), distal part elongated, with membranous outgrowth (Fig. 12D, E, F).

Female (paratype). Total length 1.55; carapace 0.73 length, 0.61 width; abdomen 0.82 length, 0.59 width. Habitus as in Fig. 11A, C, E. As in male except as noted. Carapace: without any pattern. Mouthparts: chelicerae and endites unmodified. Abdomen: dorsal scutum well sclerotized, postepigastric scutum boat-shaped, very narrow. Genitalia: anterior margin of the postepigastric scutum slightly sclerotized, behind the anterior margin is a depression (dp); the winding tube runs posteriorly (wt), ending in a bowl-shaped atrium (bsa) (Fig. 11 G–K).

Distribution.

Singapore.