Tidarren obtusum, Knoflach & Harten, 2006

Knoflach, Barbara & Harten, Antonius Van, 2006, The one-palped spider genera Tidarren and Echinotheridion in the Old World (Araneae, Theridiidae), with comparative remarks on Tidarren from America, Journal of Natural History 40 (25 - 26), pp. 1483-1616 : 1585-1590

Tidarren obtusum n. sp.

( Figures 186 , 190–192 , 247–258 , 259c ; Tables XXVIII, XXIX)

Type material

Madagascar: 1♀ holotype , 3♀ paratypes, CAS, Mahajanga Prov., Réserve d’Ankoririka , 10.6 km 13 ° NE de Tsaramandroso, 16 ° 169020S, 46 ° 029550E, 210 m, 9–14 April 2001, tropical dry forest, general coll. night, leg. J. J. Rafanomezantsoa et al., JJR0148. 1 „ paratype, CAS CASENT 9002892, Mahajanga Prov., Parc National d’Ankarafantsika, Forêt de Tsimaloto , 18.3 km 46 ° NE de Tsaramandroso, 16 ° 139410S, 46 ° 089370E, 135 m, 2–8 April 2001, tropical dry forest, EF28 beaten from low vegetation, leg. J. J. Rafanomezantsoa et al., JJR0147. 1♀ paratype, CTh, Perinet , 18 ° 569S, 48 ° 259E, 10 November 1995, near water, leg. T. Kopf.

Other material examined

Madagascar: 2♀, CAS, Mahajanga Prov., Parc National d’Ankarafantsika, Forêt de Tsimaloto , 18.3 km 46 ° NE de Tsaramandroso, 16 ° 139410S, 46 ° 089370E, 135 m, 2–8 April 2001, tropical dry forest, general coll. night, leg. J. J. Rafanomezantsoa et al., JJR0145 . 1♀, CAS, Mahajanga Prov., Parc National d’Ankarafantsika, Ampijoroa Station Forestière, 40 km 306 ° NW Andranofasika, 16 ° 199150S, 46 ° 489380E, 130 m, 26 March to 1 April 2001, tropical dry forest, EF28 beaten from low vegetation, leg. Fisher, Griswold et al., BLF3524 . 1♀, CAS, Mahajanga Prov., Parc National d’Ankarafantsika, Ampijoroa Station Forestière, 40 km 306 ° NW Andranofasika, 16 ° 199150S, 46 ° 489380E, 130 m, 26 March to 1 April 2001, tropical dry forest, general collect. night, leg. J. J. Rafanomezantsoa et al., JJR0142. 1juv ♀, CAS, Antsiranana Prov., Foret d’Orangea , 3.6 km 128 ° SE Remena, 12 ° 159320S, 49 ° 229290E, 90 m, 22–28 February 2001, littoral rainforest, EG28 beaten from low vegetation, leg. Fisher, Griswold et al., BLF3202 .

Etymology

The specific epithet refers to the obtuse epigynal protuberance, from the Latin adjective obtusus. The suffix agrees with the gender of the genus name.

Diagnosis

Among the species from Madagascar T. obtusum shows the least projecting epigynum, its protuberance being a rounded, scarcely sclerotized knob ( Figures 186 , 251–258 ). In contrast to T. aethiops from mainland Africa the protuberance is not laterally incised ( Figures 251 , 255 ), the copulatory orifices being situated at its anterior border. The male is characterized by the sclerotized prolateral part of the conductor, which is strongly protruding ( Figures 190, 191 , 247, 249 ). Cymbium distally tapering, with apical warts ( Figures 247–250 ). Distal rim of tegulum with two sclerotized, rounded processes ( Figure 247 ).

Measurements (mm)

[„ n 51/ ♀ n 58, minimum–maximum (mean).] Total length 1.17/2.82–3.56 (3.13), carapace length 0.52/1.07–1.29 (1.17), width 0.43/0.88–1.07 (0.98), length femur I 0.57/1.76–2.51 (2.15), tibia I 0.35/1.01–1.48 (1.24). Abdomen 0.74/2.15–3.09 (2.7) high, 0.62/1.68–2.27 (2.0) long, and 0.49/1.41–1.92 (1.7) wide. Ventral side (distance petiolus to spinnerets) 0.51/1.21–1.64 (1.39) long. Clypeus in male 0.23 high, in females on average 0.27. Chelicerae 0.20/0.46 long. Sternum 0.32/0.64–0.74 (0.70) long and 0.30/0.57–0.68 (0.62) wide. Labium 0.05/on average 0.16 long, 0.10/0.27 wide. Gnathocoxae 0.15/0.41 long, 0.06/0.16 wide. Femur of male palp 0.31 long. Leg formula 1423, see Tables XXVIII, XXIX. Number of dorsal setae on tibiae I–IV 2/2/1/2. Trichobothria in retrodorsal/ prodorsal row on tibia of female palp 2/1, of female legs I–IV 3/?, 3/?, 3/2, 3/3 (1♀ examined), of male legs I–IV 2/1, 2/1, 1/2, 2/2. Metatarsi I–III with one trichobothrium, position on I 0.30 (0.23), on II 0.30 (0.30), on III 0.35 (0.34) in female (male). Tarsal claws of legs with three side teeth in female, with only one side tooth in male, claw of female palp consisting of seven teeth. Tarsal organ on female palp at 0.76, on female legs I–IV 0.42, 0.35, –, 0.33, on male legs I–IV 0.23, 0.28, 0.28, 0.26.

Somatic features, colouration ( Figures 186 , 190–192 )

Sternum without posterior tubercle. Abdomen higher than long, ending in tubercle. Female ( Figures 186 , 192 ). Carapace yellow with dark median area from eye region to centre, sometimes also with dark margins. Chelicerae yellow, rarely suffused with greyish longitudinal stripes at margins. Gnathocoxae and labium pale yellow. Sternum with variable pattern, from pale yellow with indistinct greyish margins and undulations to distinct pattern, covering posterior half of sternum, or sternum even mainly dark with several light spots. Legs and palps light yellow with dark patches and annulations of various extent. Coxae light yellow. Abdomen whitish to yellowish, with white line pattern and some dark pigmentation. Dorsum with broad whitish longitudinal band, ending on tubercle and surrounded by dark pigmentation. One short anterior and one longer posterior white line curve downwards laterally. Aboral area yellowish, with clear white median stripe from apex to spinnerets and one or two interrupted dark transverse bands. Epigastric region yellowish, epigynal area sometimes darkened, book lung covers pale yellow. Venter yellowish, sometimes with a few dark and white spots. Spinnerets light brown.

Male ( Figures 190, 191 ). Carapace yellow with dark median area from clypeus to centre. Chelicerae light brown, mainly suffused with grey. Gnathocoxae and labium brown. Sternum dark brown. Legs pale yellow with dark patches and annulations. Coxae distally slightly darkened. Basal segments of male palp pale yellow with brown patches, cymbium brown. Abdomen yellowish to whitish, with dark pigmentation and white spots. Anterior half dark, posterior half light. Epigaster dark, book lung covers yellow. Venter dark, with two small white paramedian spots. Spinnerets brown.

Male palp ( Figures 247–250 )

Tibia distally ca 0.7 width of palpal organ; its base ca 0.4 width of distal rim ( Figure 248 ). Cymbium tapering, with two small distal lobes, and intermediate part with several rows of apical warts. Cymbium scarcely projecting beyond bulbus. Bulbus ca 0.2 mm long and 0.25 mm wide. Distal rim of tegulum with two sclerotized, rounded projections. Retrolateral, membranous part of conductor 0.16 mm long, its tip pointed, with furrow guiding embolus. Prolateral part with conspicuous, large, sclerotized process ( Figures 247, 249 , visible also in Figures 190, 191 ) and a smaller inner one close to tip of membranous part; their distal surfaces bear some warts. Embolar base circular, 0.05 mm in diameter, with two small basal lobes. Distal part of embolus 0.2 mm long.

Epigynum, vulva ( Figures 251–258 )

Epigynal protuberance short and rounded ( Figures 186 , 251 , 255 ), 0.08–0.09 mm long in side view; protuberance itself scarcely sclerotized, thus appearing whitish in contrast to darker surrounding integument ( Figure 253 ); posterior, aboral side delimited from surrounding integument ( Figures 253 , 257 ). Copulatory orifice at anterior border of epigynal protuberance, in ventral and dorsal view level with posterior end of receptacula. Copulatory ducts with separate orifices ( Figures 252–254 , 256–258 ), ca 0.1 mm long; they diverge anteriorly and then laterally and enter receptacula at posterior inner side. Receptacula seminis 0.13–0.16 mm long and 0.10–0.12 mm wide. Epigynal protuberance about 0.7 length of receptacula (in ventral view, Figures 252 , 256 ).

Matching of sexes

It cannot be definitely assured that the male is conspecific with the females, as different species may occur together in the same region. However, the single male was collected from exactly the same locality as two females. Also the yellowish colouration of the carapace agrees with that of the females.

Distribution ( Figure 259c )

Tidarren obtusum occurs in several places on Madagascar.

Figures

Figure 259. (a, b) Tidarren sp. from Madagascar, Nosy Be. Left male palp, expanded, prolateral (a) and retrolateral (b). (c) Distribution of four Tidarren species, T. argo Knoflach and van Harten, T. cuneolatum (Tullgren), T. obtusum n. sp., and T. scenicum (Thorell).

Figures 181–186. Female habitus. (181, 182) Tidarren ubickorum n. sp. from South Africa (181) and Zimbabwe (182). (183) T. usambara n. sp. from Tanzania. (184, 185) T. horaki n. sp. from Madagascar, Toamasina (184) and Antsiranana (185). (186) T. obtusum n. sp. from Madagascar. Auto-Montage digital photos from specimens preserved in alcohol.

Figures 187–195. Habitus of female (187, 188, 192–195), subadult male (189), and adult male (190, 191). (187, 194) Tidarren apartiolum n. sp. from Madagascar. (188, 189) T. dasyglossa n. sp. from Madagascar, Toamasina (188) and Betroka (189). (190–192) T. obtusum n. sp. from Madagascar, Ankarafantsika, Forêt de Tsimaloto (190, 191) and Perinet (192). (193) T. ubickorum n. sp. from South Africa. (195) T. horaki n. sp. from Madagascar, Toamasina. Photos from specimens preserved in alcohol.

Figures 247–250. Tidarren obtusum n. sp. from Madagascar, Ankarafantsika, Forêt de Tsimaloto. Right male palp, prolateral (247), dorsal (248), retrolateral (249), and retrolateral-ventral view (250). Scale bar: 0.2 mm.

Figures 251–254. Tidarren obtusum n. sp., from Madagascar, Ankarafantsika, Ampijoroa station (251–253) and Forêt de Tsimaloto (254). Female epigynum/vulva in lateral (251), ventral (252, 254), and aboral view (253). Scale bars: 0.1 mm.

Figures 255–258. Tidarren obtusum n. sp., from Madagascar, Perinet. Female epigynum/vulva in lateral (255), ventral (256), aboral (257), and dorsal view (258). Scale bar: 0.2 mm.