Ischnothyreus ascifer 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 : 37-42

Ischnothyreus ascifer Richard , sp. nov.

( Figs. 27–30 )

Type material. Holotype: male (PBI_OON00052388), SUMATRA : North Sumatra Province, hill forest 1.5km SE of Kampus Kehutanan Aeknauli, near road Prapat-Pematangsiantar, 13km from Prapat , 2°42’38”N, 98°56’16”E, 1150m; June 30 / July 2, 2006, leg. P. Schwendinger. Sum-06/30, Natural History Museum Geneve .

Paratypes: 5 males (PBI_OON00032329), collected with holotype.

Additional material examined. 1 male (PBI_OON00032329), SUMATRA: N . Sumatra, Gn. Leuser Ketambe, April 11, 1986 l. litter , May 4, 1986, trail, coll. Deeleman, NNM Leiden; 1 male (PBI_OON00012425), 1 male (PBI_OON00031882), SUMATRA: N . Sumatra, Gn. Leuser Ketambe, lowland leaflitter, May 1–August 9, 1985, leg. Suharto, Coll. Deeleman, NNM Leiden . 1 male (PBI_OON00031462), SUMATRA: N . Sumatra, Gn. Leuser Ketambe, lowland leaflitter, May 1 – August 9, 1985, leg. Suharto, Coll. Deeleman, NNM Leiden.

Etymology. The species epithet is a noun in apposition and a combination of the Latin words for axe (ascia) and carry (ferre), referring to the shape of the tip of the male palpal bulb.

Diagnosis. Males of I. ascifer sp. nov. can be recognized by the tip of the bulb which bears a conspicuous membraneous process on the dorsal side, appearing axe-shaped in lateral view (asm, Figs. 28 E–H, 30A–C). Also the chelicerae are very characteristically shaped with a flat process that winds around the fang anteriorly and a conspicuous protuberance on the retrolateral side of the paturon (p, rh, Figs. 29 C, D, 30F, G).

Description. Male: (PBI_OON00052388). Total length 1.70; carapace length: 0.82; carapace width: 0.70; abdomen length; 0.85.

CEPHALOTHORAX: Carapace pale orange, without any pattern, broadly oval in dorsal view, pars cephalica strongly elevated in lateral view, anteriorly narrowed to 0.49 times its maximum width or less, surface of elevated portion of pars cephalica smooth, sides finely reticulate; lateral margin straight, smooth. Clypeus margin unmodified, straight in front view, sloping forward in lateral view, high, ALE separated from edge of carapace by their radius or more, with dark triangles on outer edge of clypeus at level of posterior eye row (t, Fig. 27 D). Eyes six, well developed, ALE largest, ALE oval, PME squared, PLE oval; posterior eye row straight from above, procurved from front; ALE touching, ALE-PLE touching, PME touching throughout most of their length, PLE- PME touching. Sternum as long as wide, pale orange, uniform, surface smooth, microsculpture absent, lateral margin without infra-coxal grooves, distance between coxae approximately equal, extensions of pre-coxal triangles absent, lateral margins unmodified; setae, dark, needle-like, evenly scattered, originating from surface. Mouthparts: Chelicerae, endites and labium pale orange. Chelicerae straight, anterior face unmodified, paturon with conspicious protuberance on lateral edge; directed medially, shape normal, tip unmodified; setae dark, needlelike, densest medially. Paturon with retrolateral protuberance (rh, Figs. 29 C, D, 30G). Fang with flat process (p, Figs. 29 C, D, 30F, G). Labium rectangular, not fused to sternum, anterior margin not indented at middle, same as sternum in sclerotization; with 6 or more setae on anterior margin, subdistal portion with unmodified setae. Endites distally not excavated, anteromedian tip with one strong, tooth-like projection, much more heavily sclerotized than sternum.

ABDOMEN: ovoid, pointed posteriorly; dorsum soft portions yellow, without color pattern. Posterior spiracles not connected by groove. Scutum extending far dorsal of pedicel. Dorsal scutum weakly sclerotized, pale orange, without color pattern, covering less than 1/2 of abdomen, between 1/4 and 1/2 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, pale orange, short, almost rectangular, covering about 1/3 of the abdominal length, fused to epigastric scutum, anterior margin unmodified. Dorsum setae present, dark, needle-like. Spinneret scutum with fringe of long setae. Interscutal membrane with setae.

LEGS: pale orange, without color pattern; patella plus tibia I shorter than carapace, tibia I unmodified. Leg spination: femora: I p0-1-1; II p0-0-1; tibiae: I p2-1-1; r2-1-1; II p2-1-1; r2-2-0; metatarsi: I, II p1-1-0; r1-1-0.

GENITALIA: Bulb with two large pointed ventral protuberances, retrolateral lobe modified (rl, Figs. 28 G, H, 30A–C). Tip of bulb slightly elongated, with ventral pit and dorsal axe-shaped membrane (asm, Figs. 28 E–H).

Female: Unknown.

Distribution. Known only from north-western Sumatra.

Figures

FIGURE 27. Ischnothyreus ascifer 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 28. Ischnothyreus ascifer sp. nov. Male: A, G, right palp, retrolateral view; B, H, right palp, prolateral view; C, E, right embolus, retrolateral view; D, F, right embolus, prolateral view. asm, axe-shaped membrane; rl, retrolateral lobe. Scale bars: A, G = 0.1 mm.

FIGURE 29. Ischnothyreus ascifer sp. nov. Male: A, C, left chelicera, anterior view; B, D, left chelicera, posterior view. p, process; r, rostrum; rh, retrolateral hump. Scale bars: B, D = 0.1 mm.

FIGURE 30. Ischnothyreus ascifer sp. nov. Male, SEM images: A, mouthparts and right palp, ventral view; B, left bulbus, prolateral view; C, right embolus, retrolateral view; D, sperm pore, ventral view; E, tarsal organ leg; F, fang and denticles of right chelicera, anterior view; G, right chelicera, anterior view. asm, axe-shaped membrane; eo, embolic opening; p, process; rh, retrolateral hump; rl, retrolateral lobe. Scale bars: A, G = 0.1 mm; B, D = 50 µm; C, F = 20 µm; E = 5 µm.