Psechrus khammouan, Jäger, Peter, 2007

Jäger, Peter, 2007, Spiders from Laos with descriptions of new species (Arachnida: Araneae), Acta Arachnologica 56 (1), pp. 29-58 : 47

Psechrus khammouan spec. nov.

Figs. 54-67

Type material. Male holotype ( SMF 56386 ), Laos, Khammouan Prov., 9.5 km NE Thakek (L34), 159 m altitude, N 17°26.936', E 104°52.499', foot cave and surroundings , by hand, P. Jäger & V. Vedel leg. 30.X.2004 . 1 female paratype ( SMF 56388 ), Laos, Khammouan Prov., 2.5 km WNW Ban Thathot (L27), 200 m altitude, cave entry 17° 37.897', E 105°07.502, cave exit N 17°37.994', E 105.07195 ', primary forest between street and limestone cave Tham Kamouk , P. Jäger leg. 19.11.2003 . 1 female paratype ( SMF 56387 ), Laos, Khammouan Prov., 2.5 km WNW Ban Thathot (L28), 200 m altitude, cave entry 17° 37.897', E 105°07.502, cave exit N 17°37.994', E 105.07195 ', Tham Kamouk, entrance hall and in the cave , P. Jäger leg. 19.11.2003 .

Etymology. The species is named after Khammouan Province, noun in apposition.

Diagnosis. Small Psechrus species (12.2-14.5 body length). Males similar to those of P. singaporensis sensu Levi (1982: fig. 42) in course of sperm duct, arising point and shape of embolus and basal white patch (‘window’) on tegulum, but having embolus and conductor longer, tibia and cymbium more elongated and arising point of conductor closer to the centre of tegulum ( Figs. 54- 56 , 60-61 ). Females similar to those of P. singaporensis sensu Levi (1982: figs. 44, 46) in the general course of internal duct system, but distinguished by the antero-median position of the glandular appendages ( Figs. 58 , 63 ).

Description. Male. PL 5.0, PW 3.5, AW 1.9, OL 7.2, OW 2.7. Leg II: 37.7 (10.2, 2.0, 10.6, 10.7, 4.2). Embolus arising roughly in a 12-o’clock-position, bent prolaterodistad, with thin and pointed tip. Conductor longer than embolus, becoming broader distally ( Figs. 55 , 60 ). Dorsal cymbial scopula extending in the distal third to half ( Fig. 56 ). Distal tibia with two brushes of long bristles ventrally ( Figs. 60-61 ), a short apophysis retrolatero-dorsally ( Figs. 54, 56 ), and a retrolateral tibial spine as long as bulb ( Fig. 60 ).

Female. PL 5.3-6.2, PW 3.5-4.2, AW 2.1-2.4, OL 7.7- 8.3, OW 3.1-3.3. Leg II: 30.7-34.3 (8.6-9.6, 2.0-2.3, 8.8- 10.0, 7.8-8.7, 3.5- 3.7). Epigynal field semicircular; muscle sigillae longer then in P. luangprabang spec, nov., separated from the field about 1.0 their length; two pairs of slit sense organs close to sigillae; epigynal furrows slightly undulated, forming roughly a trapezoid; posterior margin of median septum straight ( Figs. 57 , 62 ); internal duct system with lateral copulatory openings, running first mediad, then turning latero-posteriorad, passing two loops before ending in fertilisation ducts; anterior turning point with two glandular appendages on each side ( Figs. 58-59 , 63 ).

Egg-sac: diameter 10.0-11.0; contained 71 pre-larvae.

Colour (in ethanol). ( Figs. 64-67 ) Dorsal shield of prosoma with two dark longitudinal bands, these with darker radial markings and distinct and smooth margins; bright median band widening anteriorly, having two faint patches in its anterior part between eyes and fovea. Sternum with distinct bright lateral bands, reaching not the anterior margin of sternum; dark v-shaped patch reaching posterior margin of sternum, patch with only slight brightening in its centre. Dorsal opisthosoma bright with pairs of dark patches, mainly in posterior half. Ventral opisthosoma with thin median line, diverging on epigastric furrow and in direction of petiolus, without bright patch or interruption in front of spinnerets. Legs annulated and with dark spine patches. Ventral leg coxae with white patches, on coxae I largest.

Distribution. Known so far only from Khammouan Province from two places: Ban Thathot (L27-28) and vicinity of Thakek (L34).

Figures

Figs. 54 - 59. Psechrus khammouan spec, nov., male holotype from Thakek (L 34), female paratype from Tham Kamouk (L 27 - 28). 54 - 56 Male pedipalpus (54 prolateral, 55 ventral, 56 retrolateral view); 57 epigynum, ventral view; 58 left half of internal duct system, dorsal view; 59 Schematic course of internal duct system, dorsal view, c — conductor, e — embolus, ga — glandular appendage.

Figs. 60 - 63. Psechrus khammouan spec, nov., male holotype from Thakek (L 34), female paratype from Tham Kamouk (L 27 - 28). 60 - 61 Male pedipalpus, showing 2 ventral hair-brushes on apical tibia (60 ventral, 61 retrolateral view); 62 epigynum, ventral view; 63 internal duct system, dorsal view.

Figs. 64 - 71. 64 - 67 Psechrus khammouan spec, nov., male holotype and female paratype from Ban Keng Koung (L 15). 64 - 65 Male (64 dorsal, 65 ventral view); 66 - 67 female (66 dorsal, 67 ventral view). 68 - 71 Psechrus luangprabang spec, nov., male holotype from Thakek (L 34), female paratype from Tham Kamouk (L 27 - 28). 68 - 69 Male (68 dorsal, 69 ventral view); 70 - 71 female (70 dorsal, 71 ventral view); all in ethanol.