Ischnothyreus baltenspergerae Richard,

Richard, Miguel, Graber, Werner & Kropf, Christian, 2016, The goblin spider genus Ischnothyreus (Araneae, Oonopidae) in Java and Sumatra, Zootaxa 4151 (1), pp. 1-99: 7-11

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Ischnothyreus baltenspergerae Richard

sp. nov.

Ischnothyreus baltenspergerae Richard  , sp. nov.

( Figs. 1–3View FIGURE 1View FIGURE 2View FIGURE 3)

Type material. Holotype: male (PBI_OON00052399), JAVA: E  . Java, Mt. Ljen , 600m, July 8, 1979, coll. Deeleman, NNM Leiden. 

Etymology. The species epithet is dedicated to Dr. Yvonne Kranz-Baltensperger, a NMBE arachnologist and expert of the genus Ischnothyreus  .

Diagnosis. Males of I. baltenspergerae  sp. nov. resemble males of I. ovinus Edward & Harvey, 2014  in palpal and cheliceral morphology but can be distinguished from it by the tip of the bulb which is apically divided into two lobes (ad, Figs. 2View FIGURE 2 E, F). The bulb has a single large flat ventral protuberance and the retrolateral lobe appears rather unconspicious (rl, Figs. 2View FIGURE 2 A –H). The base of the fang is slightly thickened but without a conspicuous process ( Figs. 3View FIGURE 3 C, D).

Description. Male: (PBI_OON00052399). Total length: 1.51; carapace length: 0.78; carapace width: 0.62; abdomen length; 0.81.

CEPHALOTHORAX: Carapace yellow, with dark brown egg-shaped patches behind eyes, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, anteriorly narrowed to 0.49 times its maximum width or less, with rounded posterolateral corners, surface of elevated portion of pars cephalica smooth, sides smooth; lateral margin straight, smooth; non-marginal pars cephalica setae dark, needle-like; marginal setae dark, needlelike. Clypeus margin unmodified, straight in front view, sloping forward in lateral view, high, ALE separated from edge of carapace by their radius or more. Eyes six, well developed, ALE largest, ALE oval, PME squared, PLE oval; posterior eye row procurved from both above and front; ALE touching, ALE-PLE touching, PME touching throughout most of their length, PLE-PME touching. Sternum longer than wide, yellow, uniform, with radial furrows between coxae I –II, II –III, III –IV, furrow smooth, surface smooth, microsculpture absent, lateral margin without infra-coxal grooves, distance between coxae approximately equal, lateral margins unmodified; setae, dark, needle-like, evenly scattered, originating from surface. Mouthparts: Chelicerae, endites and labium yellow. Chelicerae straight, anterior face unmodified; directed medially, shape normal; setae dark, needle-like, evenly scattered. Base of the fang slightly thickened ( Figs. 3View FIGURE 3 C, D). Labium rectangular, not fused to sternum, anterior margin not indented at middle, same as sternum in sclerotization; with setae. Endites distally not excavated, anteromedian tip with one strong, tooth-like projection, much more heavily sclerotized than sternum.

ABDOMEN: ovoid, rounded posteriorly; dorsum soft portions white, without color pattern. Book lung covers large, elliptical, without setae. Posterior spiracles not connected by groove. Pedicel tube short, unmodified, scutopedicel region unmodified, scutum extending far dorsal of pedicel. Dorsal scutum weakly sclerotized, yellow, without color pattern, covering 1/2 to 3/4 of abdomen, more than 1/2 to most of abdomen width, not fused to epigastric scutum, middle surface smooth, sides smooth. Epigastric scutum weakly sclerotized, surrounding pedicel, not protruding, small lateral sclerites absent. Postepigastric scutum weakly sclerotized, yellow, short, only around epigastric furrow, fused to epigastric scutum, anterior margin unmodified. Dorsum setae present, dark, needle-like. Epigastric area setae uniform, dark, needle-like. Postepigastric area setae present, dark, needle-like. Spinneret scutum with fringe of needle-like setae.

LEGS: yellow, without color pattern. Leg spination unknown respectively legs lacking in holotype.

GENITALIA: Epigastric region with sperm pore large, circular, situated at level of anterior spiracles, unmodified. Palp strongly sclerotized, proximal segments almost black; embolus dark; trochanter with ventral projection; femur shorter than trochanter; patella about as long as femur, not enlarged, setae unmodified; cymbium almost black, ovoid in dorsal view, fused with bulb but with clearly defined seam between, not extending beyond distal tip of bulb; bulb almost black, more than 2 times as long as cymbium, slender, tapering apically. Bulb with one large flat ventral protuberance, retrolateral lobe simple (rl, Figs. 2View FIGURE 2 A –H). Tip of bulb elongated, bent dorsally, divided into two lobes (ad, Figs. 2View FIGURE 2 E, F).

Female: Unknown.

Distribution. Known only from Mt. Ljen in eastern Java.


National Museum of Natural History, Naturalis


Naturhistorisches Museum der Burgergemeinde Bern