Loxosceles mrazig, Ribera & Planas, 2009

Ribera, Carles & Planas, Enric, 2009, A new species of Loxosceles (Araneae, Sicariidae) from Tunisia, ZooKeys 16 (16), pp. 217-225 : 221-222

Loxosceles mrazig sp. n.

urn:lsid:zoobank.org:act:A8F75878-85CA-4567-874B-EBC8CC24CD02

Figs 2-7

Material examined. 1 male (Holotype) from Douz , Tunisia, 33° 24’ 26.77’’ N, 09°02’41.92’’E, 27 January 2007, Cesc Múrria leg. ( CRBA-LX 1054) .

Material for comparison. 2 males, 2 females of L. gaucho ( CRBA-LX1024 ) from Sao Paulo, Brazil, November 2007, A. Brescovit leg. ; 2 males, 2 females of L. laeta ( CRBA-LX1028 ) from Montevideo, Uruguay, L. Acosta leg. ; 1 male, of L. rufescens ( CRBA-LX1012 ) from Gavà, Barcelona, López-Pancorbo leg.

Etymology. The species’ name honours the people called Mrazig, formerly nomadic, living in and around the city of Douz ( Tunisia). The Mrazig are the descendants of the Banu Saleim tribe that fled the Arabian Peninsula in the seventh century and came to Tunisia in the thirteenth century. It is known that they practiced transhumance in the Great Sahara. Noun in apposition.

Diagnosis. Differs from L. gaucho , L. rufescens and its similar relatives in the proportion of male palp segments, mainly the tibia. In L. mrazig the tibia is markedly oval, slightly longer than wide (0.63 - 0.54) ( Figs 2, 3, 5 ); in L. gaucho it is ¾ as wide as long ( Gertsch 1967, plates 3-4), whereas, in L. rufescens , it is slightly oval, although dorsally almost straight ( Gertsch 1967, plate 10). Also differs from L. rufescens by the size of the tegulum and the size and shape of the embolus ( Figs 2-5 ). Body pigmentation yellowish-brown in L. gaucho and pale yellow in L. mrazig . In general, the morphological differences compared to L. rufescens are more conspicuous. The size of the tegulum and, especially, the shape and length of the embolus are clearly different.

Description. Colouration: Carapace pale yellowish with a fine, pale brown lateral stripe. Median groove and adjacent integuments darkened. Pars cephalica slightly darkened, brown coloured, and clearly demarcated by a lateral reddish brown line. Less conspicuous, but still important, diagnostic traits are the four thin longitudinal lines (lightly impressed when seen under higher magnification) located in the centre of the pars cephalica ( Fig. 6 ). Eye tubercles black. Sternum pale yellowish, paler than carapace. Labium and gnathocoxae with slightly more pigmentation. Legs light yellow or somewhat shaded, with the apical segments slightly darkened. Opisthosoma yellowish-white.

Prosoma. Carapace ( Fig. 6 ) slightly longer (2.39) than wide (2.15). Median groove deep, occupying the posterior third of carapace. Clypeal width slightly more than 2.5 diameters of ME. Eyes close together ( Fig. 7 ); LE separated from ME by the diameter of ME. LE larger than ME (0.18 - 0.1 respectively). Sternum about ⅔ as wide as long, extended between the IV pair of coxae. Labium as long as wide at its base, apically narrowed and rounded. Gnathocoxae distally convergent, enclosing the labium.

Opisthosoma elongate oval in dorsal view.

Male palp ( Figs 2-5 ). Femur cylindrical, more than five times longer than wide. Tibia short, oval, slightly longer than wide. Tarsus flattened below, slightly shorter than tibia, rounded apically. Tegulum large, 4/5 as wide as tarsal length. Embolus enlarged at base, forming a sinuous curve, about 1.5 times longer than tegulum.

Measurements. Male (holotype): Prosoma 2.15 wide, 2.39 long: opisthosoma 3.22 long. Total body length 5.61. Legs: I: coxa 0.81, trochanter 0.23, femur 5.42, patella 0.84, tibia 5.70, metatarsus 5.76, tarsus 1.38, total length 20.14; II: coxa 0.58, rest of segments missing. III: coxa 0.81, trochanter 0.23, femur 4.94, patella 0.82, tibia 4.69, metatarsus 5.37, tarsus 1.12, total length 17.98; IV: coxa 0.81, trochanter 0.23, femur 5.26, patella 0.84, tibia 5.40, metatarsus 6.42, tarsus 1.33, total length 20.29; Palp: femur 1.19, patella 0.36, tibia 0.63, tarsus 0.56, total length 2.74.

Female unknown.

Distribution. So far, L. mrazig is known only from the type locality. The unique specimen was collected in a dune of sand near the city of Douz.

Figures

Figures 2-5. Male palp of Loxosceles mrazig sp. n. 2 prolateral view 3 retrolateral view 4 apical view 5 dorsal view.

Figures 6-7. Prosoma of Loxosceles mrazig sp. n. 6 dorsal view, arrow indicates the four longitudinal lines located in the centre of the pars cephalica 7 frontal view.