Ischnothyreus nentwigorum 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 : 26-29

Ischnothyreus nentwigorum Richard , sp. nov.

( Figs. 17–19 )

Type material. Holotype: male (PBI_OON00052401), JAVA: W . Java, Cibodas , 1500–1600m, December 1986, leg. Suh. Djojosudharmo, Coll. Deeleman, NNM Leiden.

Etymology. The specific name is a patronym in honor of Prof. Wolfgang Nentwig and Dr. Lucia Kuhn- Nentwig from the Institute of Ecology and Evolution at the University of Bern, Switzerland.

Diagnosis. Males of I. nentwigorum sp. nov. strongly resemble males of I. florifer Kranz-Baltensperger, 2011 and I. ligulatus sp. nov. in their palpal morphology with the distal spoon-shaped appendage but can be distinguished from them by the tip of the bulb being somewhat shorter in I. nentwigorum sp. nov. (ssa, w, Figs. 18 A–H) and the double process on the cheliceral fang base (p, Figs. 19 C, D), which is lacking in the former species.

Description. Male: (PBI_OON00052401). Total length 1.64; carapace length: 0.82; carapace width: 0.67; carapace height: 0.37; abdomen length; 0.87; abdomen width: 0.42; sternum length: 0.47; sternum width: 0.45; dorsal abdominal scutum length: 0.76; dorsal abdominal scutum width: 0.40.

CEPHALOTHORAX: Carapace pale orange, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, anteriorly narrowed to between 0.5 and 0.75 times its maximum width, surface of elevated portion of pars cephalica smooth, sides smooth; lateral margin straight, smooth. Clypeus margin unmodified, curved downwards in front view, vertical in lateral view, high, ALE separated from edge of carapace by their radius or more. Eyes six, well developed, ALE largest, ALE circular, PME oval, PLE oval; posterior eye row procurved from both above and front; ALE touching, ALE-PLE touching, PME touching, PLE-PME touching. Sternum as long as wide, yellow, uniform, surface smooth, microsculpture absent, lateral margin without infra-coxal grooves, distance between coxae approximately equal, extensions of pre-coxal triangles present, lateral margins unmodified; setae sparse, dark, needle-like, evenly scattered, originating from surface. Mouthparts: Chelicerae, endites and labium pale orange. Chelicerae straight, anterior face unmodified, directed medially, shape normal, tip unmodified, fang base with double process (p, Figs. 19 C, D) pointing anteriorly and ventrally if fang is closed, both processes about half the length of the fang, anterior process thinner than ventral process, both curved.; setae dark, needle-like, evenly scattered; paturon inner margin with scattered setae.

Labium rectangular, not fused to sternum, anterior margin not indented at middle, same as sternum in sclerotization. Endites distally not excavated, anteromedian tip with one strong, tooth like projection.

ABDOMEN: cylindrical, rounded posteriorly; dorsum soft portions white, without color pattern. Book lung covers small, very narrow, without setae. Posterior spiracles not connected by groove. Scutum not extending far dorsal of pedicel. Dorsal scutum weakly sclerotized, pale orange, without color pattern, covering more than 3/4 of abdomen, more than 1/2 to most of abdomen width, 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, long, almost rectangular, covering about 3/4 of abdominal length, fused to epigastric scutum, anterior margin unmodified. Dorsum setae present, dark, needle-like. Spinneret scutum with fringe of needle-like setae. Interscutal membrane with setae.

LEGS: pale orange, without color pattern. Leg spination: femora: I p0-1-1; II p0-0-1; tibiae: I, II p2-2-0; r2-2- 0; metatarsi: I, II p1-1-0; r1-1-0. Tarsi I to IV superior claws tooth not examined in detail.

GENITALIA: Bulb with one large ventral protuberance, retrolateral lobe simple. Tip of bulb slightly elongated, blunt, with spoon-shaped less-sclerotized appendage, wrinkled dorsally at buckling between bulb and embolus (ssa, w, Figs. 18 A–H).

Female: Unknown.

Distribution. Known only from Cibodas in western Java.

Figures

FIGURE 17. Ischnothyreus nentwigorum sp. nov. Male: A, habitus, dorsal view; B, habitus, lateral view; C, habitus, ventral view; D, carapace, frontal view; E, sternum, ventral view; F, opisthosoma, dorsal view; G, opisthosoma, ventral view. Scale bar: A = 1 mm.

FIGURE 18. Ischnothyreus nentwigorum sp. nov. Male: A, G, left palp, retrolateral view; B, H, left palp, prolateral view; C, E, left embolus, retrolateral view; D, F, left embolus, prolateral view. rl, retrolateral lobe; ssa, spoon-shaped appendage; w, wrinkles. Scale bars: A, G = 0.2 mm.

FIGURE 19. Ischnothyreus nentwigorum sp. nov. Male: A, D, right chelicera, anterior view; B, mouthparts, ventral view; C, right chelicera, posterior view. p, double process. Scale bars: A, C = 0.1 mm.