Sesieutes thakek, Jäger, Peter, 2007

Jäger, Peter, 2007, Spiders from Laos with descriptions of new species (Arachnida: Araneae), Acta Arachnologica 56 (1), pp. 29-58: 48-49

publication ID 10.2476/asjaa.56.29

persistent identifier

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scientific name

Sesieutes thakek

spec. nov.

Sesieutes thakek  spec. nov.

Figs. 73-82View Figs. 73 - 82

Type material. Male holotype ( SMF 56635), Laos, Khammouan Prov., 9.5 km NE Thakek  (L34), 159 m altitude, N 17°26.936', E 104°52.499', leaf litter in front of cave, by sieving, P. Jäger & V. Vedel leg. 30.X.2004GoogleMaps  .

Etymology. The species is named after the province capital Thakek  (= Muang Khammouan), closely situated to the type locality, noun in apposition.

Diagnosis. Medium sized Sesieutes  species (5.2 mm body length). Male similar to that of S. schwendingeri Deeleman-Reinhold 2001  (figs. 771-772) according to general arrangement of copulatory organ and colouration, but having base of embolus broader and bent dorsad ( Fig. 73View Figs. 73 - 82; narrower and bent basad in S. schwendingeri  ), tegulum distinctly pear-shaped ( Fig. 74View Figs. 73 - 82; not that wide basally in S. schwendingeri  ), and ventral prosomal granulations restricted to the central part of the sternum ( Fig. 80View Figs. 73 - 82; dense granulation in sternum, labium and gnathocoxae in S. schwendingeri  ).

Description. Male. PL 2.6, PW 1.9, AW 1.05, OL 2.6, OW 1.5. Leg II: 8.95 (2.45, 0.85, 2.4, 2.05, 1.2). Spination: femur I 2 pl; tibia I 9 pv, 9 rv, II 8 pv, 7rv, III 1 pv, 1 rv, 1 rl, IV 3 pv, 2 rv, 1 rl; metatarsus I 5 pv, 6 rv, II 5 pv, 5 rv, III 1 pl, 1 pv, 1 rv, 1 rl, IV 2 rv, 1 rl; Femoral spines with small basal tooth and with large, toothed socket ( Figs. 81- 82View Figs. 73 - 82). Leg claws with 4- 5 teeth. Dorsal scutum 0.5 OS length. Chelicerae with three promarginal and 2 small retromarginal teeth ( Fig. 80View Figs. 73 - 82).

Embolus arising in 10-o’clock-position, running first distad, then dorsad ( Fig. 73View Figs. 73 - 82), finally ending in a distal coil, with its plane transverse to that of the alveolus; tip of embolus running semi-circular, becoming narrower distally ( Fig. 77View Figs. 73 - 82). Functional conductor short, slightly bent, arising in a 11-o’clock-position ( Fig. 74View Figs. 73 - 82). Tip of embolus resting in conductor in unexpanded pedipalpus ( Fig. 77View Figs. 73 - 82). Subtegulum visible in prolateral view ( Fig. 73View Figs. 73 - 82). Sperm-duct on retrolateral side ( Fig. 75View Figs. 73 - 82) in similar position as in S. schwendingeri  . Pedipalpal tibia with retrolateral blunt distal hump and retrolateral basal apophysis, the latter with distinct ridge ( Fig. 76View Figs. 73 - 82). Cymbial scopula similar as in S. schwendingeri  , i.e. extending in the distal third to quarter of dorsal cymbium ( Fig. 75View Figs. 73 - 82). Ventral scutum of OS with small bent rim in front of genital opening ( Fig. 78View Figs. 73 - 82).

Colour and granulation (in ethanol). Dorsal shield of PS dark reddish brown, with dense and distinct granulations, fovea small, circular, striae less distinct. Sternum brighter reddish brown, with slight radial striae and granulations in the centre, these fading marginally ( Fig. 80View Figs. 73 - 82). Labium and gnathocoxae bright redbrown, with striae and very sparse and small granulations; legs and ventral scutum of OS yellowish brown, with fine granulations, on distal segments less distinct, femora darker. Petiolus anteriorly with ventral median keel. Dorsal OS dark grey with reddish brown scutum, behind that with two white lateral patches, behind those with 4 slightly recurved white chevrons and white patch in front of spinnerets. Ventral OS generally brighter than dorsal side, with lateral rows of small bright patches. Spinnerets with apical segment white, basal segments grey. Female, unknown.

Distribution. Known only from the type locality


Germany, Frankfurt-am-Main, Forschungsinstitut und Naturmuseum Senckenberg