Tetrablemma namkhan , Lin, Yucheng, Li, Shuqiang & Jäger, Peter, 2012

Lin, Yucheng, Li, Shuqiang & Jäger, Peter, 2012, Two new species of the family Tetrablemmidae (Araneae) from Laos and Malaysia, Zootaxa 3475, pp. 55-64: 60

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Tetrablemma namkhan

sp. nov.

Tetrablemma namkhan  sp. nov.

Figs 4–6View FIGURES 4 A – GView FIGURES 5 A – CView FIGURES 6 A – C

Type material: Holotype: male ( SMFAbout SMF), Laos, Luang Prabang Prov., SE Luang Prabang, Xiang Ngeun Distr., Nam Khan, Ban Keng Koung, 19 ° 40 ʹ 963 ʺN, 102 ° 18 ʹ 442 ʺE, altitude 372 m, disturbed forest, valley, waterfall, dry stream bed, P. Jäger leg. 21–23 February 2008, Winkler extraction.

Etymology. The specific epithet refers to the type locality, the Nam Khan (= River Khan); noun in apposition.

Diagnosis. This new species is similar to T. magister  from Queenland (see Burger 2008: figs. 15–20), T. brevidens  from China (see Tong & Li 2008: figs. 5 A–C, F–H) and T. thamin  from Myanmar (see Labarque & Grismado 2009: figs. 1, 3, 6–9) in the shape of the prosoma in lateral view, but males can be distinguished by the presence of an anterior dorsal lump on the male prosoma ( Fig. 4 CView FIGURES 4 A – G), the short and S-shaped cheliceral apophysis in dorsal view ( Figs 4 E–FView FIGURES 4 A – G), the tortuous and six curves sperm duct ( Figs 5 A, BView FIGURES 5 A – C; 6 A, B), and the slightly curved, wide embolus ( Figs 5 CView FIGURES 5 A – C; 6 C vs Burger 2008: fig. 19, Tong & Li 2008: fig. 5 F and Labarque & Grismado 2009: fig. 3).

Description. Male (holotype). Colouration: Prosoma reddish-brown, opisthosoma and legs pale reddishbrown to yellowish-brown. Somatic characters see Figs 4 A–GView FIGURES 4 A – G.

Measurements: Total length 1.16. Prosoma length 0.56, width 0.47, height 0.53. Opisthosoma length 0.77, width 0.61, height 0.46. Clypeus height 0.36. ALE 0.071, PLE 0.054. Sternum length 0.32, width 0.36. Legs: I 1.28 (0.43, 0.13, 0.30, 0.21, 0.21); II 1.19 (0.38, 0.13, 0.27, 0.20, 0.21); III 1.07 (0.32, 0.13, 0.23, 0.20, 0.20); IV 1.38 (0.43, 0.13, 0.36, 0.25, 0.21).

Prosoma: Dorsal shield sclerotised, finely reticulate, except smooth radial region. Cephalic part elevated, surface smooth, planar, anteriorly sloping forward. Thoracic part marginally rugose with smooth striae. Ocular area situated centrally on prosoma, with four eyes in a tetrad, eye base black, AME and PME absent. ALE>PLE. Clypeus very wide, completely reticulate, margin rounded. Chelicerae surface smooth, cheliceral horn robust, Sshaped in dorsal view, a small tubercle at cheliceral horn basally. Cheliceral laminae developed. Gnathocoxae basally wide, distally narrow. Labium subtriangular. Sternum wider than long, with fine reticulation, marginally rugose.

Legs: All femora with granules and annular veins. Other segments sculptured. Femur I slightly swollen. Metatarsus I proximo-mesially contracted, with two small tubercles. Tibiae I–IV with three trichobothria, metatarsus I–IV with one trichobothrium. Leg formula: IV-I-II-III.

Opisthosoma: Dorsal scutum ovoid, finely reticulate, covered with long setae. Ventral scutum reticulate, posterior region slightly crinkled, booklung cover smooth. Lateral scutum I long, exceeding posterior margin of pre-anal plate. Postgenital plate present, as wide as pre-anal plate. Pre-anal plate rectangular, wider than long, covered sparsely with plumose setae, overlapping with posterior margin of postgenital plate.

Pedipalp ( Figs 5–6View FIGURES 5 A – CView FIGURES 6 A – C): Femur finely granulated, slightly swollen, subequal to tibia in length, with two long ventral setae proximally. Patella short, subequal to 1 / 2 width of tibia, without modification. Tibia strongly swollen, with distal trichobothrium dorsally. Cymbium shorter than patella, with few long setae dorsally. Bulb pear-shaped. Spermophor course with several bends. Embolus short, strongly sclerotised, curving mesially and weakly furcate distally.

Female: Unknown.

Distribution. Known only from the type locality.


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