Ischnothyreus ruyuanensis Tong, 2023

Fu, Hongjin, Wang, Zengxue, Sun, Yufei, Tong, Yanfeng & Bian, Dongju, 2023, A new species of Ischnothyreus Simon, 1893 (Araneae, Oonopidae) from Guangdong Province, China, Biodiversity Data Journal 11, pp. 105283-105283 : 105283

Ischnothyreus ruyuanensis Tong sp. n.

Materials

Type status: Holotype. Occurrence: catalogNumber: SYNU-674 ; recordedBy: Weihua Cheng ; individualCount: 1; sex: male; lifeStage: adult; occurrenceID: EEC9560A-524B-5DB2-ADF0-C5871DFD4D51; Taxon : scientificName: Ischnothyreus ruyuanensis; order: Araneae ; family: Oonopidae ; genus: Ischnothyreus ; Location : country: China; stateProvince: Guangdong; county: Shaoguan City ; locality: Ruyuan Yao Autonomous County, LalingYaozhai ; verbatimElevation: 350 m; verbatimCoordinates: 24°45.816'N, 113°14.183'E; Identification : identifiedBy: Yanfeng Tong ; Event : samplingProtocol: sifting leaf litter; eventDate: 04/12/ 2021 Type status: Paratype. Occurrence: catalogNumber: SYNU-675-676 ; recordedBy: Weihua Cheng ; individualCount: 2; sex: female; lifeStage: adult; occurrenceID: C0EF0169-B026-531F-9AE1-EEABBCEF2814; Taxon : scientificName: Ischnothyreus ruyuanensis; order: Araneae ; family: Oonopidae ; genus: Ischnothyreus ; Location : country: China; stateProvince: Guangdong; county: Shaoguan City ; locality: Ruyuan Yao Autonomous County, LalingYaozhai ; verbatimElevation: 350 m; verbatimCoordinates: 24°45.816'N, 113°14.183'E; Identification : identifiedBy: Yanfeng Tong ; Event : samplingProtocol: sifting leaf litter; eventDate: 04/12/2021

Description

Male (Holotype). Body: habitus as in Fig. 1 A-C; body length 1.37. Carapace: 0.65 long, 0.58 wide; yellow, oval in dorsal view, pars cephalica strongly elevated in lateral view, surface of elevated portion of pars cephalica and sides finely reticulated, lateral margin straight, smooth (Fig. 1 E). Clypeus: curved in frontal view, ALE separated from edge of carapace by 0.7 times their diameter (Fig. 1 H). Eyes: ALE largest, ALE circular, PME squared, PLE oval; posterior eye row recurved from above; ALE separated by less than their radius, ALE and PLE touching (Fig. 1 E and H). Sternum: as long as wide, pale orange (Fig. 1 B and F). Mouthparts: chelicerae, endites and labium yellow; chelicerae straight, anterior face with strong, thorn-like process (tlp), base of fangs with very long sclerotised process (lsp), fang groove with a few small denticles (Fig. 3 A, G and H); anteromedian tip of endites with one strong, tooth-like projection (stp) (Fig. 1 F). Abdomen: 0.64 long, 0.41 wide; dorsal scutum dark brown, covering 4/5 of abdomen width and approximately 5/6 of abdomen length, not fused to epigastric scutum; postepigastric scutum covering 2/3 of abdomen length. 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. Palp: trochanter with ventral projection (vp); bulb with two ventral protuberances (vpr), distal end of bulb with dorsal membrane (dm) and large ventral lobe (vl) (Fig. 3 B-F).

Female (SYNU-675). Same as male, except as noted. Body: habitus as in Fig. 2 A-C; body length 1.65. Carapace: 0.61 long, 0.60 wide. Mouthparts: chelicerae and endites unmodified. Abdomen: 0.89 long, 0.62 wide. Epigastric area (Fig. 2 D): postepigastric scutum narrow (lenght/width = 3.3), its anterior margin slightly thickened (asr), with dark sclerotised ridge in the middle (msr) of postepigastric scutum. Endogyne (Fig. 3 I and J): with 2 strongly curved sclerites (csr), winding tube (wt) long, strongly convoluted.

Diagnosis

The new species is similar to I. spineus Tong & Li, 2012 in the thorn-like process on the male chelicerae, but can be distinguished by the thorn-like process nearly straight (Fig. 1 H, Fig. 3 G and H) vs. strongly curved (see Tong and Li (2012): fig. 3D and H), the sclerotised process of fang base more than 1/3 the whole fangs' length (Fig. 3 G and H) vs. less than 1/4 the whole fangs' length (see Tong and Li (2012): figs. 3H and 5C) and the dark sclerotised ridge (msr) in the middle of the postepigastric scutum (Fig. 2 D) vs. a semi-circular depression (see Tong and Li (2012): figs. 4G and 5D).

Etymology

The specific epithet is an adjective referring to the type locality.

Distribution

Known only from the type locality.

Figures

Figure 1. Ischnothyreus ruyuanensis sp. n., holotype male. A habitus, dorsal view; B habitus, ventral view; C habitus, lateral view; D abdomen, ventral view; E prosoma, dorsal view; F prosoma, ventral view; G prosoma, lateral view; H prosoma, anterior view. Abbreviation: stp = strong, tooth-like projection. Scales: 0.4 mm.

Figure 2. Ischnothyreus ruyuanensis sp. n., paratype female. A habitus, dorsal view; B habitus, ventral view; C habitus, lateral view; D epigastric region, ventral view; E prosoma, dorsal view; F prosoma, ventral view; G prosoma, lateral view; H prosoma, anterior view. Abbreviations: asr = anterior sclerotised ridge, csr = curved sclerotised ridge, msr = middle sclerotised ridge, wt = winding tube. Scales: A-C 、 E-H = 0.4 mm; D = 0.2 mm.

Figure 3. Ischnothyreus ruyuanensis sp. n., male holotype, A-C (SEM) and D-H (light); female paratype, I-J (light). A left chelicerae, anterior view; B left palp, prolateral view; C distal part of palpal bulb, prolateral view; D left palp, prolateral view; E left palp, retrolateral view; F left palp, dorsal view; G left chelicerae, anterior view; H left chelicerae, posterior view; I endogyne, ventral view; J endogyne, dorsal view. Abbreviations: ap = apodemes, csr = curved sclerotised ridge, dm = dorsal membrane, lsp = long sclerotised process, tlp = thorn-like process, vl = ventral lobe, vp = ventral projection, vpr = ventral protuberances, wt = winding tube. Scales: A, B, D-H = 0.1 mm; C = 0.05 mm; I, J = 0.2 mm.