Ischnothyreus spineus, Tong, Yanfeng & Li, Shuqiang, 2012

Tong, Yanfeng & Li, Shuqiang, 2012, Four new species of the genus Ischnothyreus from Hainan Island, China (Araneae, Oonopidae), Zootaxa 3352, pp. 25-39 : 29

Ischnothyreus spineus sp. nov.

( Figs 3–5 , 11 )

Type material: 1 male Holotype ( IZCAS Ar 19319), sifting leaf litter, China: Hainan, Haikou City, Dongzhaigang Mangrove Natural Reserve, Alt. - 2 m, 19°57.113´N, 110°33.983´E, August 20, 2007, leg. Shuqiang Li; 3 female paratypes, same data as holotype.

Etymology: The specific name refers to the strong thorn-like process on the chelicerae; adjective.

Diagnosis: The male can easily be recognized by the flower-like distal part of the palp and the very strong, curved, thorn-like process on the chelicerae ( Figs 3 D, H, 5C). The female can be recognized by the shallow, semicircular depression at the anterior margin of the postepigastric scutum and the sponge-like structure in the genital area ( Figs 4 G, H, 5D, E).

Description: Male (holotype). Total length 1.21 mm. Carapace: orange-brown, without any pattern, broadly oval in dorsal view, pars cephalica slightly elevated in lateral view, surface and sides strongly reticulate. Eyes: six, well developed, ALE largest, PME smallest; posterior eye row procurved from both above and front. Mouthparts: chelicerae slightly divergent, with slightly sclerotized process at base of fangs (ssp) and one strong, curved thornlike process (tlp) in the middle of the laterodorsal surface; fang groove with many small denticles ( Figs 3 H, 5C). Anterior margin of labium not indented at middle. Anteromedian tip of endites with one strong, tooth-like projection. Abdomen: scutum extending far dorsal of pedicel. Dorsal scutum covering about 3/4 of abdomen, about 1/2 of abdomen width, not fused to epigastric scutum. Epigastric scutum weakly sclerotized, postepigastric scutum absent. Leg spine formula: femur I with 2 prolateral and 1 small retrolateral spine, tibia I with 4 pairs, metatarsus I with 2 pairs of long ventral spines. Spination of leg II similar to leg I except femur with only one prolateral spine. Legs III and IV spineless. Genitalia: Sperm pore situated at level of anterior spiracles. Palp strongly sclerotized, trochanter with ventral projection (vp); femur normal size; patella about as long as femur, not enlarged; cymbium not fused with bulb; bulb with two small ventral protuberances (vpr), at the bending site with a lobe (l); tip of bulb with membranous, flower-like outgrowth (flo) ( Figs 3 I, J, 5A, B).

Female (paratype). Total length 1.32 mm. As in male except as noted. Eyes: posterior eye row strongly procurved from above. Mouthparts: chelicerae and endites unmodified. Abdomen: dorsal scutum covering about 1/2 of abdomen, about 1/3 of abdomen width. Postepigastric scutum absent, with short posteriorly directed lateral apodemes. Genitalia: anterior margin of postepigastric scutum with a shallow semi-circular depression (scd), at its middle a tube, with round tip (rt), connected posteriorly to a strongly winding tube (wt); from dorsal view, the tube penetrates through a sponge-like structure (sls), and ends at near the epigastric furrow ( Figs 4 G, H, 5D, E).

Distribution: Known only from Hainan Island.

Figures

FIGURE 3. Ischnothyreus spineus sp. nov., male. A – C, habitus, dorsal, lateral and ventral views; D – G, prosoma, frontal, dorsal, lateral and ventral views; H, left chelicera, anterior view; I, J, left palp, prolateral and retrolateral views. flo, flower-like outgrowth; ssp, slightly sclerotized process; tlp, thorn-like process; vp, ventral projection. Scales: A – C = 0.4 mm; D – G = 0.2 mm; H – J = 0.1 mm.

FIGURE 4. Ischnothyreus spineus sp. nov., female. A, B, C, habitus, dorsal, lateral and ventral views; D, prosoma, dorsal view; E, prosoma, frontal view; F, abdomen, ventral view; G, genital area, ventral view; H, genital area, dorsal view. rt, tube with round tip; scd, semi-circular depression; sls, sponge-like structure; wt, winding tube. Scales: A, B, C = 0.4 mm; D – F = 0.2 mm; G, H = 0.05 mm.

FIGURE 5. Ischnothyreus spineus sp. nov. A, left male palp, prolateral view; B, left male palp, retrolateral view; C, left male chelicera, anterior view; D, female genital area, ventral view; E, female genital area, dorsal view. a, apodeme; flo, flower-like outgrowth; l, lobe; rt, tube with round tip; scd, semi-circular depression; sls, sponge-like structure; ssp, slightly sclerotized process; tlp, thorn-like process; vp, ventral projection; vpr, ventral protuberance; wt, winding tube. Scales: 0.1 mm.

FIGURE 11. Localities of four new Ischnothyreus species from Hainan Island, China.