A new species of the genus Ischnothyreus Simon, 1893 from Chongqing, China(Araneae: Oonopidae)

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(1. College of Life Science, Shenyang Normal University, Shenyang 110034, China;2. Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences,Yezin Nay Pyi Taw 05282, Myanmar;3. Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China)

0 Introduction

Oonopidae are very small (≤3 mm), free-living, mostly ground-dwelling spiders. They are haplogyne and usually have six eyes, which are grouped close together[1]. The Oonopidae are an extremely diverse spider family, with currently 1780 described species in 114 genera[2]. They occur on all continents but are most abundant and diverse in the tropics and subtropics[3]. Oonopids are found in very diverse habitat types, such as leaf litter, tree canopy, under bark or in dead wood and some are even adapted to special habitats such as bird or ant nests or termite mounts[4].

The genusIschnothyreusis one of the largest genera in the family Oonopidae, with 104 valid specific names recorded worldwide, but the presently recognized species may represent only a small fraction of the actual biodiversity[5-6]. The genusIschnothyreuscan be recognized by the presence of leg spines, the usually small abdominal scutum, the strongly sclerotized male palps, the heavily sclerotized male endites and the winding genital tube in the females[7].

The fauna ofIschnothyreusin China have been poorly studied, only 14 species of this genus were reported from China previously. Among these 14 species,I.yueluensiswas recorded in Hunan[8],I.linzhiensiswas recorded in Tibet[9],I.flagellicheliswas recorded in Anhui[10],I.kentingensis,I.narutomiiandI.peltiferwere recorded in Taiwan[11-12],I.narutomii,I.peltiferand the other eight endemic species were recorded in Hainan[13-15].

Here we present one additional new species, collected from Chongqing Municipality. It is the first time this genus recorded from Chongqing.

1 Material and methods

The specimens were examined using a Leica M205C stereomicroscope. Details were studied under an Olympus BX51 compound microscope. Photos were made with a Canon EOS 550D zoom digital camera (18 megapixels) mounted on an Olympus BX51 compound microscope. Vulvae were cleared in lactic acid.For scanning electron microscopy (SEM), specimens were air-dried, and without gold coating. Pictures were taken with a Hitachi TM3030. All measurements were taken using an Olympus BX51 compound microscope and are in millimeters.

The following abbreviations are used in the text:ALE=anterior lateral eyes;PLE=posterior lateral eyes;PME=posterior median eyes.

All specimens are deposited in Shenyang Normal University(SYNU) in Shenyang, China.

2 Results

IschnothyreuszhoujiayanTong&Li,sp.nov.

Typematerials. Holotype: male(SYNU-206), sifting leaf litter, Zhoujiayan Village, Yongxing Town, Jiangjin District, Chongqing Municipality, 106°14′3.840″E, 28°54′36.876″N, 518.700 m, October 18, 2014, leg. Y. Tong. Paratypes: 1 male, 3 females(SYNU-206), same data as holotype.

Etymology. The specific name is a noun in apposition taken from the type locality.

Diagnosis. The new species is similar toI.flagellichelisXu, 1989 andI.falcatusTong & Li, 2008, but can be distinguished by the strongly, forked shaped process on male chelicerae (Fig.2) and the large, bell-shaped atrium in the female genital area (Fig.5h,5i,5j).

Description. Male(holotype). Total length 1.72; carapace 0.85 length, 0.71 width; abdomen 0.87 length, 0.62 width. Habitus as in Fig.1a,1b,1c.Carapace: yellow, dark brown on lateral and posterior surfaces, 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.1d,1f).Clypeus: straight in frontal view, vertical in lateral view, ALE separated from edge of carapace by their diameter 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.1d,1g).Sternum: longer than wide, pale orange, uniform, not fused to carapace, surface smooth, setae sparse.Mouthparts: chelicerae, endites and labium orange. Chelicerae straight, with slightly sclerotized process(ssp) at base of fangs and one very strong, fork like process(flp) in the middle of the laterodorsal surface, fang groove with a few small and one larger denticles(Fig.2). Labium rectangular, fused to sternum, anterior margin not indented at middle. Anteromedian tip of endites with one strong, tooth-like projection(stp in Fig.1e).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 2/3 of abdomen width and approximately 3/4 of abdomen length, not 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 spines, tibia Ⅰ with four pairs, metatarsus Ⅰ with two pairs of long ventral spines. Leg Ⅱ lost. Legs Ⅲ and Ⅳ spineless(Fig.3).Genitalia: epigastric region with sperm pore large sized, circular, situated at level of anterior spiracles. Palp strongly sclerotized, right and left palps symmetrical, trochanter with ventral projection(vp), cymbium brown, fused with bulb, bulb brown, more than two times as long as cymbium, tapering apically, with two small ventral protuberances(vpr), distal part elongated, with membranous leaf-shaped apophyses (lsa) (Fig.4).

Fig.1 Ischnothyreus zhoujiayan sp. nov., male. (a) habitus, dorsal view (b) habitus, ventral view (c) habitus, lateral view (d) prosoma, dorsal view (e) prosoma, ventral view (f)prosoma, lateral view (g) prosoma, anterior view. Abbreviation: stp=strong, tooth-like projection. Scales: (a)～(c)=0.4 mm; (d)～(g)=0.2 mm

Fig.3 Ischnothyreus zhoujiayan sp. nov., female, left legs, SEM. (a) leg Ⅰ, prolateral view (b) tarsus Ⅰ,prolateral view (c) leg Ⅱ, prolateral view (d) tarsus Ⅱ, prolateral view (e) leg Ⅲ, prolateral view (f) tarsus Ⅲ, prolateral view (g) leg Ⅳ, prolateral view (h) tarsus Ⅳ, prolateral view.

Fig.4 Ischnothyreus zhoujiayan sp. nov., male, left palp, (a)～(f), SEM. (a) prolateral view (b) distal part of bulb, prolateral view (c) dorsal view (d) distal part of bulb, dorsal view (e) retrolateral view (f) distal part of bulb, retrolateral view (g), (h), (i) prolateral, dorsal and retrolateral views.

Fig.5 Ischnothyreus zhoujiayan sp. nov., female. (a), (c), (e) habitus, dorsal, ventral and lateral views (b), (d), (f), (g) prosoma, dorsal, ventral, lateral and anterior views (h), (i) genitalia, ventral views (j) genitalia, dorsal view. Abbreviations: a=apodemes; bsa=bell-shaped atrium; pls=plate-like sclerite; wt=winding tube. Scales: (a), (c), (e)=0.4 mm; (b), (d), (f)～(j)=0.2 mm

Female(one of the paratypes). Total length 1.65; carapace 0.81 length, 0.68 width; abdomen 0.94 length, 0.63 width. Habitus as in Fig.5a,5c,5e. As in male except as noted.Mouthparts: chelicerae and endites unmodified.Abdomen: dorsal scutum covering about 4/5 of abdomen length, 2/3 of abdomen width. Postepigastric scutum rectangular(Fig.5c,5h).Genitalia: the posterior margin of the epigastric scutum is lined with numerous needle-like setae. The epigastric groove is narrow. From dorsal view, the middle of the plate like sclerite(pls) runs a dark, winding tube posteriorly(wt), ending in a large, bell-shaped atrium(bsa)(Fig.5i,5j).

Distribution. China(Chongqing).

Acknowledgements

This study was supported by the National Natural Science Foundation of China(NSFC-31372157,31572237) to Tong Yanfeng, by the National Natural Science Foundation of China(NSFC-31471960,31530067) and the Southeast Asia Biodiversity Research Institute, Chinese Academy of Sciences(2015CASEABRI005,Y4ZK111B01) to Li Shuqiang.

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