Silhouettella curieusei, Benoit, 1979

Alvarez-Padilla, Fernando, Ubick, Darrell & Griswold, Charles E., 2015, Indian Ocean goblin spiders (Araneae, Oonopidae): four new species of pelicinoids from Madagascar, with a redescription of the type species Silhouettella curieusei Benoit, 1979, American Museum Novitates 2015 (3835), pp. 1-32 : 4-6

Silhouettella curieusei, Benoit, 1979

Figures 1–8 , 48–63 , 99

Silhouettella curieusei Benoit, 1979: 202 , fig. 5D–H. Holotype male and female paratype from Silhouette Island, Mare aux Cochons , sur Pandanus seychellarum , Seycheles Archipelagous, 500 m (3–4 July 1972, Benoit, P.L.G. and Van Mol J.J.), deposited in MRAC 146.563, PBI_OON 6264 (examined).

DIAGNOSIS: S. curieusei can be differentiated from S. usgutra species by larger eyes and the carapace smooth with its pars cephalica strongly elevated ( Saaristo and van Harten, 2002: fig. 3). The species differs from S. betalfa , S. osmaniye , and S. tomer by lacking a lateral protuberance on the dorsal lamella middle section ( Saaristo, 2007: “X” in figs. 93B, 99B; Topçu et al., 2012: fig. 5). Unique characters for these species are: sternum microsculpture covering entire surface with a reticulated pattern (figs. 2, 50). Femora and tibiae basally half darkened with a wide band.

DESCRIPTION: Male (PBI_OON 36153). Total length 1.2. Cephalothorax: Carapace orangebrown, without any pattern, broadly oval in dorsal view, anteriorly narrowed to between 0.5 and 0.75 times its maximum width, with rounded posterolateral corners, fovea absent (fig. 1), posterolateral edge with pair of pits, posterior margin not bulging below posterior rim, anterolateral corners without extension or projections, posterolateral surface without spikes, surface of elevated portion of pars cephalica smooth, sides smooth, thorax without depressions (figs. 3, 48), without radiating rows of pits; lateral margin straight, rebordered, with blunt denticles; plumose setae near posterior margin of pars thoracica absent (figs. 1, 49); nonmarginal pars cephalica setae light, needlelike, present in U-shaped row; nonmarginal pars thoracica setae light, needlelike. Clypeus margin slightly rebordered, straight in front view, vertical in lateral view, high, ALE separated from edge of carapace by their radius or more, median projection absent; setae present, light, needlelike. Eyes six, well developed, ALE, PME subequal, larger than PLE, all eyes oval; posterior eye row recurved from above, straight from front; ALE separated by their radius to diameter, ALE-PLE separated by less than ALE radius, PME touching throughout most of their length, PLE-PME separated by less than PME radius (figs. 1, 3, 5). Sternum longer than wide, orange-brown, uniform, fused to carapace, median concavity absent, without radial furrows between coxae I–II, II–III, III–IV, radial furrow opposite coxae III absent, surface rugose, without pits, sickle-shaped structures absent, anterior margin with pair of deep lateral pouches, posterior margin not extending posteriorly of coxae IV, anterior corner unmodified, distance between coxae approximately equal, extensions of precoxal triangles absent, lateral margins unmodified, without posterior hump; setae sparse, light, needlelike, without hair tufts (fig. 2). Mouthparts: Chelicerae without teeth only denticles observable with SEM (fig. 51), endites and labium pale orange at the base tip lighter. Chelicerae straight, anterior face unmodified; fangs directed medially, shape normal, without prominent basal process; setae light, needlelike, evenly scattered; paturon inner margin with scattered setae, distal region unmodified, inner margin unmodified (figs. 54, 55, 59). Labium triangular, not fused to sternum, anterior margin indented at middle, same as sternum in sclerotization at the base tip lighter. Endites distally excavated, anteromedian tip unmodified, posteromedian part unmodified, same as sternum in sclerotization at the base tip lighter (figs. 2, 9). Abdomen: Ovoid, without long posterior extension, rounded posteriorly, interscutal membrane rows of small sclerotized platelets absent posteriorly; dorsum soft portions white, without color pattern. Book lung covers small, very narrow, without setae, anterolateral edge unmodified (figs. 2, 3). Posterior spiracles connected by groove (figs. 7, 8). Pedicel tube short, ribbed, scutopedicel region unmodified, scutum not extending far dorsal of pedicel, plumose hairs absent, matted setae on anterior ventral abdomen in pedicel area absent (fig. 3). Dorsal scutum strongly sclerotized, pale orange, without color pattern, covering full length of abdomen, no soft tissue visible from above, not fused to epigastric scutum, middle surface smooth, sides smooth, anterior half without projecting denticles. Epigastric scutum strongly sclerotized, surrounding pedicel, not protruding, small lateral sclerites absent. Postepigastric scutum strongly sclerotized, pale orange, long, semicircular, covering nearly full length of abdominal length, fused to epigastric scutum, anterior margin unmodified, without posteriorly directed lateral apodemes (figs. 1–3). Spinneret scutum present, incomplete ring. Dorsum setae present, light, needlelike. Epigastric area setae uniform, light, needlelike. Postepigastric area setae present, dark, needlelike. Spinneret scutum with fringe of needlelike setae. Dense patch of setae anterior to spinnerets absent. Interscutal membrane with setae. Legs: Femur IV not thickened, same size as femora I–III, patella plus tibia I shorter than carapace, tibia IV specialized hairs on ventral apex absent, tibia IV ventral scopula absent, metatarsi III and IV weak ventral scopula absent. Leg spines absent. Trichobothria tibia: I three; metatarsus: I one. Genitalia: Epigastric region with sperm pore small, oval, situated at level of anterior spiracles, rebordered; furrow without Ω-shaped insertions, without setae (figs. 2, 52). Palp normal size, not strongly sclerotized, right and left palps symmetrical, proximal segments yellow; embolus light; femur normal size, two or more times as long as trochanter, without posteriorly rounded lateral dilation, attaching to patella basally; patella shorter than femur, not enlarged; cymbium yellow, narrow in dorsal view, not fused with bulb, not extending beyond distal tip of bulb, without stout setae; bulb yellow, 1 to 1.5 times as long as cymbium, stout, spherical (figs. 2, 4–6). Embolus conformed by two lamellae bent approximately 90°, both lamellae with several terminal apophysis, dorsal lamella usually with two apophysis (figs. 4, 6), ventral lamella with variable number. Male genitalia embolar lamellae as in figures 60–63.

Female: (PBI_OON 36133) as in male except as noted. Total length 1.3. As in male except as noted. Cephalothorax: Female palp spines absent. Sternum anterior margin unmodified. Endites distally not excavated (fig. 54). Female palp spines absent; tarsus unmodified. Abdomen: Postepigastric scutum not fused to epigastric scutum (fig. 53). Supraanal scutum present. Genitalia: Receptaculum wider than long. Receptaculum A1 apodemes bearing anterior and posterior extensions. A1 anterior extension aligned with apodemes A2, A1 posterior extension aligned laterally with apodemes A3. Globular appendix (GAp) of variable shape extends dorsally from receptaculum middle anterior surface, GAp aligned with T-shaped sclerite (ASc). ASc originates from posterior end of epigastric scutum. Receptaculum dorsal papillae covering at least 1/3 of its surface and visible through light microscopy. Female genitalia as in figures 7–8 and 56–58. Female genitalia as in figures 7–8 and 56–58.

DISTRIBUTION: Seychelles and Madagascar (fig. 99).

MATERIAL EXAMINED: N = 24. Seychelles: Silhouette Island: Mare aux Cochons , sur Pandanus seychellarum , 500 m, July 03, 1972 to July 04, 1972, Benoit, P.L.G. and Van Mol, J.J., 12♂, 4♀, 16 mixed paratypes ( MRAC 143.130 , PBI _ OON 36153 ); 1♂ paratype ( MRAC 144.645 , PBI _ OON 36150 ); Mt. Daub an versant Est. , 600 m, 5– 7 July, 1972, Benoit, P.L.G. and Van Mol, J.J., 2♀ paratypes ( MRAC 143.199 PBI _ OON 36172 ) . La Digue Mt. 300 m, 28–31 July 1972, Benoit, P.L.G. and Van Mol, J.J., 2♀, 3♂ paratypes ( MRAC 143.217 PBI _ OON 36152 ); Mont Corgat , on ridge toward, sifting forest litter, 445 m, 4°29′43″S, 55°14′22″E, Jan. 28–30, 2010, B.L. Fisher, 27♂, 22♀ ( CASC PBI _ OON 35470 ) ; Mont Corgat to Mont Cocos Marrons, along ridge, sifting forest litter, 455 m, 4°30′5″S, 55°14′23″E, Jan. 24–26, 2010, B.L. Fisher, 6♂, 1♀ ( CASC PBI _ OON 35470 ) . Curieuse Island : Curieuse Centre, 27 July 1972, Benoit, P.L.G. and Van Mol, J.J., 1♂ paratype ( MRAC 143.152 PBI _ OON 36151 ) . Praslin Island : Vallée de Mai, 4°19′52″S, 55°44′20″E, 200 m, sifting litter in palm forest, Feb. 2–3, 2010, B.L. Fisher, 6♂, 1♀ ( CASC PBI _ OON 35452 ) .

Figures

FIGURES 1–8. Silhouettella curieusei Benoit, 1979. 1. Habitus male, dorsal view. 2. Same, ventral view. 3. Same, lateral view. 4. Palp male, prolateral view. 5. Cephalothorax male, anterior view. 6. Palp male, retrolateral view. 7. Genitalia female, dorsal view. 8. Genitalia female, ventral view. Scale bars = 0.2 mm, except genitalia: 0.1 mm.

FIGURES 48–55. Silhouettella curieusei Benoit, 1979. 48. Cephalothorax male, dorsal view. 49. Same, lateral view. 50. Same, ventral view. 51. Chelicerae female, ventral view. 52. Epigastric region male, ventral view. 53. Epigastric region female, ventral view. 54. Endites female, ventral view. 55. Endites male, ventral view. Scale bars = 100 µm, except endites = 50 µm and female chelicerae = 10 µm.

FIGURES 56–63. Silhouettella curieusei Benoit, 1979. 56. Genitalia female, dorsal view. 57. Receptaculum, dorsal view. 58. Genitalia female, lateral view. 59. Chelicerae male, anterior view. 60. Embolus, ventral view. 61. Embolus, prolateral view. 62. Embolus, retrolateral view. 63. Embolus, dorsal view. Scale bars = 50 µm, except emboli = 10 µm.

FIGURES 99–102. Distribution maps. 99. Silhouettella curieusei Benoit, 1979, triangle; Silhouettella perismontes, new species, circle. 100. Silhouettella perisalma, new species, circles. 101. Noideattella sylvnata, new species, circles. 102. Noideattella omby, new species, circles.