Molotra tsingy, Ubick & Griswold, 2011

Ubick, Darrell & Griswold, Charles E., 2011, The Malagasy Goblin Spiders of the New Genus Molotra (Araneae: Oonopidae), American Museum Novitates 2011 (3729), pp. 1-72 : 19-20

Molotra tsingy species group

DIAGNOSIS: The single species included in this group is known only from the male, which differs from other members of the genus in being small (1.5 mm), pale in coloration, and with a smoother carapace (figs. 231–243). The palp is unusual in being twisted from the palpal axis and in resting laterally on the sternum, which lacks the typically large anterior cavities (figs. 242, 256–261). The embolar region differs from that in other Molotra in having a deep transverse groove prolaterally, lobes oriented in a vertical plane (rather than horizontal), and the presence of a dorsal and ventral prong on the prolateral surface (figs. 279–292).

SPECIES INCLUDED: Molotra tsingy .

Molotra tsingy , new species

Figures 5 , 231–292 ; map 1; table 1

TYPES: Male holotype and male paratype from Madagascar, Mahajanga, Parc National Tsingy de Bemaraha , 10.6 km ESE 123° Antsalova , 19.70944°S, 44.71805°E, 150 m, tropical dry forest on Tsingy, sifted litter (16–20 Nov 2001, B.L. Fisher et al., BLF 4432) deposited in CAS ( CASENT9010360 , PBI_OON_03397).

ETYMOLOGY: The species is named after the type locality.

DIAGNOSIS: Same as for species group.

MALE: (PBI_OON_03397): Total length 1.56. CEPHALOTHORAX: Carapace pale orange, surface of elevated portion of pars cephalica smooth, sides smooth; nonmarginal pars thoracica setae absent (figs. 239–243, 248–251). Eyes: smaller than in other Molotra species , ALE separated by more than their diameter (fig. 252). Sternum slightly longer than wide, yellow-brown, anterior excavation very narrow, surface with few small pits (figs. 242, 256, 258). Mouthparts: Endites distally excavated, anteromedian tip with strong, knoblike projection (figs. 253–255). ABDOMEN: Book lung covers oval, larger than in M. molotra group, slightly smaller than pedicel cross section (figs. 235, 262). Pedicel-scutal region lacking ridges (figs. 262, 263). Dorsal scutum yellow-brown, surface smooth (figs. 232–236). Epigastric scutum dorsal extension only slightly greater than pedicel diameter (figs. 236, 262). Postepigastric scutum with short posteriorly directed lateral apodemes (not closely examined) (fig. 238). Dorsal setae present, short. LEGS: Yellow-brown, patella plus tibia I shorter than carapace. Leg spines present, longer than leg segment width: tibiae: I v4-2-2; II v3-2-2; metatarsi I, II v 2-2-0 (figs. 244–247). Tarsal claws: superior claw surfaces striate; proclaws and retroclaws with similar dentition, with five large median teeth, laterals absent (tarsus III not examined) (figs. 271–278). GENITALIA: Epigastric region with sperm pore large, oval (figs. 238, 264, 265). Palp femur attaches to patella basally (fig. 279), tibia slightly longer than patella, embolar region with a broad, ectally concave retrolateral lobe (L2), a smaller wrinkled dorso-prolateral lobe (L1) and two prolateral prongs (fig. 287); cymbium and bulb twisted, so that the morphologically dorsal surface is positioned prolaterally (fig. 281); embolar region separated from rest of bulb by a transverse groove (fig. 290).

FEMALE: Unknown.

NOTES: This species has an interesting palp, as the bulb and tarsus are rotated relative to the main palpal axis. The embolus is thus displaced outward (retrolaterally) and, in the retracted palp, rests in the space between the edge of the sternum and coxae II and III. The anterior margin of the sternum has only a slight cavity (figs. 260, 261), similar to the condition in female Molotra (fig. 90), but unlike the deep cavities found in other Molotra males (fig. 87). This unusual mode of palpal retraction is another indication that the species may be misplaced in the genus. Additional material, especially of the unknown female, will be needed to solve this problem.

OTHER MATERIAL EXAMINED: None.

DISTRIBUTION: Known only from the type locality.

Figures

FIGS. 1–6. Molotra species, embolar region of male palpi, prolateral view. 1. M. molotra. 2. M. katarinae. 3. M. ninae. 4. M. suzannae. 5. M. tsingy. 6. M. milloti. Colors show homologous parts: yellow embolus, green dorsal lobe, red ventral lobe. The tentative homologies of the M. tsingy palp are shown as dashed lines and the unhomologized dorsal prong is shown in white dash.

FIGS. 231–238. Molotra tsingy, new species, male (PBI_OON 03397). 231. Habitus, ventral view. 232. Same, dorsal view. 233. Same, lateral view. 234. Abdomen, lateral view. 235. Same, anterior view. 236. Abdomen, dorsal view. 237. Same, ventral view. 238. Epigastric region, ventral view. Arrow to sperm pore, dash to apodeme.

FIGS. 239–247. Molotra tsingy, new species, male (PBI_OON 03397). 239. Cephalothorax, anterior view. 240. Same, posterior view. 241. Same, dorsal view. 242. Same, ventral view, showing the resting position of the embolus (arrow). 243. Same, lateral view. 244. Leg I, prolateral view. 245. Same, retrolateral view. 246. Leg IV, prolateral view. 247. Same, retrolateral view. Scale bars: 200 µm.

FIGS. 248–255. Molotra tsingy, new species, male (PBI_OON 03397). 248. Carapace, dorsal view. 249. Same, lateral view, with arrow showing posterior knob. 250. Same, anterior view. 251. Same, close up of margin, lateral view, with arrow to setose denticle. 252. Same, anterior view. 253. Mouthparts, anterolateral view, with arrow to distolateral knob of endite. 254. Sternum and mouthparts, ventrolateral view, with arrow to narrow anterior cavity of sternum. 255. Labium and endites, posterioventral view, with arrow to endite knob. Scale bars: 50 µm (251), 100 µm (all others).

FIGS. 256–261. Molotra tsingy, new species, male (PBI_OON 03397). 256. Cephalothorax, ventral view. 257. Same, magnified view showing resting position of embolar region, with arrow to wrinkled edge of lobe. 258. Cephalothorax, posteroventral view. 259. Same, magnified view, with arrow to wrinkled edge of lobe. 260. Cephalothorax, lateral view. 261. Same, magnified view showing narrow sternal cavity (arrow). Scale bars: 20 µm (257, 259), 100 µm (all others)

FIGS. 262–270. Molotra tsingy, new species, male (PBI_OON 03397). 262. Abdomen, lateral view of anterior end. 263. Same, magnified view of pedicel with arrows showing absence of ridges. 264. Epigastric region, ventrolateral view, dashes to anterior respiratory spiracle and arrow to apodeme opening. 265. Sperm pore, ventral view. 266. Tarsal organ of palpus, dorsal view. 267. Same, tarsus II. 268. Same, tarsus IV. 269. Trichobothrium of tibia IV, sublateral view. 270. Same, tibia II, dorsal view. Scale bars: 100 µm (262), 50 µm (263, 264), 20 µm (265), 10 µm (266–270).

FIGS. 271–278. Molotra tsingy, new species, male claws (PBI_OON 03397). 271. Claws of tarsus I, prolateral view. 272. Same, retroventral view. 273. Same, anterior view. 274. Same, dorsolateral view. 275. Claws of tarsus II, ventrolateral view. 276. Same, retrolateral view. 277. Claws of tarsus IV, prolateral view. 278. Same, retrolateral view. Lateral teeth absent, median teeth labeled (M). Scale bars: 10 µm.

FIGS. 279–284. Molotra tsingy, new species, male palp. (PBI_03397). 279. Prolateral view, methyl salicylate prep. 280. Same, after treatment in hot lactic acid and showing no obvious expansion. 281. Bulb and cymbium in dorsal view, arrow shows degree of rotation relative to the rest of the palp, dotted line gives the approximate axis of rotation. 282. Subprolateral view. 283. Ventral view. 284. Retrolateral view. DP = dorsal prong, L1 = smaller lobe, L2 = larger lobe, VP = ventral prong. Scale bars: 200 µm.

FIGS. 285–292. Molotra tsingy, new species, male palp. (PBI_03397). 285. Palp, prolateral view. 286. Same, retrolateral view. 287. Embolar region, prolateral view. 288. Same, apical view. 289. Palp, dorsal view. 290. Embolar region, dorsal view, arrow to subapical groove, dashes to prongs. 291. Palp, dorsolateral view. 292. Embolar region, prolateral view. DP = dorsal prong, L1 = smaller lobe, L2 = larger lobe, O = embolar opening, VP = ventral prong. Scale bars: 100 µm (285, 286, 289, 291), 20 µm (287, 288, 290, 292).