Description. Male (MZSP 26076). Total length: 21.4. Carapace: length 8.52; width 6.98. Eye tubercle: length 1.18; width 1.52. Labium: length 0.5; width 1.37. Sternum: length 4.37; width 3.65. Basal segment of chelicera with 8 teeth. Labium with 3 cuspules. Maxilla with 20 – 23 cuspules. Thoracic fovea slightly recurved. Palp: femur 4.53 / patella 2.9 / tibia 3.43 / cymbium 1.78 / total 12.64. Legs I: femur 7.8 / patella 4.46 / tibia 5.76 / metatarsus 5.44 / tarsus 3.33 / total 26.79. II: 6.98 / 3.91 / 5.09 / 4.89 / 3.13 / 24. III: 6.06 / 3.05 / 4.32 / 4.99 / 3.1 / 21.52. IV: 7.95 / 3.73 / 6.41 / 6.89 / 3.57 / 28.55. Spines: Palp: femur (d) 0 - 0 - p 1, patella 0, tibia (v) 0 - 0 - 1, (p) 1 - 1 - 1; Legs: I: femur (d) 0 - 0 - p 1, patella 0, tibia (v) 2 - 2 - ap 1, (p) 0 - 1 - 0, metatarsus (v) r 1 - 0 - 0; II: femur (d) 0 - 0 - 2, patella 0, tibia (v) 2 - 2 - ap 2, (p) 0 - 1 - 1, metatarsus (v) 1 - 0 - 0; III: femur (d) 1 - 5 - 3, patella 0, tibia (r) 1 - 1 - 0, (v) 4 - 3 - ap 2, (p) 1 - 1 - 0, metatarsus (r) 1 - 1 - 0, (v) 0 - 2 - ap 3, (p) 1 - 1 - 1; IV: femur (d) 1 - 5 - 3, patella 0, tibia (r) 1 - 1 - 1, (v) 3 - 3 - ap 3, (p) 0 - 1 - 1, metatarsus (r) 1 - 1 - 1, (v) 2 - 0 - ap 3, (p) 1 - 1 - 1. Retrolateral lobe of cymbium slightly larger than prolateral lobe. Palpal bulb with short embolus, bent distally (Fig. 4), with small subapical keel (Figs. 2 – 5). Retrolateral branch of tibial spur with spine inserted on its midlength, internal branch with spine inserted on its base (Fig. 1). Metatarsus I bends retrolaterally to tibial spur. Carapace reddish. Abdomen dark with some clear setae (Fig. 8). Female (MZSP 23224). Total length: 21.1. Carapace: length 9.17; width 7.46. Eye tubercle: length 1.32; width 1.65. Labium: length 0.64; width 1.64. Sternum: length 4.12; width 3.92. Basal segment of chelicera with 8 – 10 teeth. Labium with 3 cuspules. Maxilla with 19 – 20 cuspules. Palp: femur 4.58 / patella 3.33 / tibia 2.75 / tarsus 2.85 / total 13.51. Legs I: femur 6.59 / patella 4.57 / tibia 4.5 / metatarsus 3.98 / tarsus 2.61 / total 22.25. II: 5.75 / 3.92 / 3.71 / 3.56 / 2.5 / 19.44. III: 5.24 / 3.2 / 3.31 / 3.82 / 2.6 / 18.17. IV: 6.85 / 4.04 / 5.35 / 5.54 / 2.94 / 24.72. Spines. Palp: femur (d) 0 - 0 - p 1, patella 0, tibia (v) 0 - 2 - ap 2, (p) 0 - 1 - 0. Legs I: femur (d) 0 - 0 - p 1, patella 0, tibia (v) 0 - 1 - ap 1, (p) 0 - 1 - 0, metatarsus (v) r 1 - 0 - 0. II: femur (d) 0 - 0 - p 1, patella 0, tibia (v) 0 - 1 - ap 1, (p) 0 - 1 - 0, metatarsus (v) r 1 - 0 - 0. III: femur (d) 0 - 0 - 1, patella 0, tibia (r) 1 - 1 - 0, (v) 0 - 2 - ap 2, (p) 1 - 1 - 0, metatarsus (r) 0 - 1 - 1, (p) 1 - 1 - 1, (v) 0 - 2 - ap 2. IV: femur 0, patella 0, tibia (r) 0 - 1 - 1, (v) 0 - 1 - ap 2, metatarsus (r) 0 - 1 - 1, (v) p 1 - 4 - ap 3, (p) 0 - 1 - 0. Spermathecae paired, receptacula short, as wide as long, with apical termini (Fig. 6). Coloration similar to male (Fig. 7). Note. This species has a very wide distribution, from central Brazil to eastern Bolivia. Although spiders in different populations show variation in color (Figs. 7 – 12), they all have the same genitalia morphology, and therefore are assigned to the same species. Natural history. In their revision, Gerschman & Schiapelli (1973) stated that spiders of some Ischnocolinae can be found under stones and fallen trunks. Similarly, Vol (2001) stated that the specimens that he described, were collected inside houses as well as under rocks with silk. The specimens studied herein, from Samaipata, Bolivia (Figs. 15 – 16) were collected under rocks (Dirk Weinmann, pers. com.), as was the material from the type-locality, Catalão, Goiás, Brazil (Figs. 13 – 14). Both of these areas are dry environments, but the forest in Brazil, called " cerradão ", has a denser canopy than the habitat in Bolivia, where only some scattered trees are present. At the other locality in Bolivia, Rurrenabaque, Beni, the specimens were collected between the leaf stalk and the tree trunk (Figs. 17 – 18; Dirk Weinmann, pers. com.). Both specimens from Catalão were raised in captivity until they molted into adults. Each one was placed in a terrarium with 7 cm layer of soil and a large stone. The spiders built a tunnel web between the stone and the glass of the terrarium; the tunnel could be seen from outside (Figs. 19 – 20). Several times, the spiders were seen carrying small portions of soil grains and sticking them to the web, until the tunnel was completely covered with soil. This behavior may be interpreted as an attempt to hide the web from predators, since it would not be easily seen. The spiders were seen and fed at both entrances of the tunnel. Apparently, they showed no preferences for either entrance. Beneath the stone, the tunnels branched into several secondary, smaller tunnels through which the spider would walk rapidly.
Guadanucci, José Paulo Leite (2007): A revision of the Neotropical spider genus Oligoxystre Vellard 1924 (Theraphosidae, Ischnocolinae). Zootaxa 1555: 1-20, DOI: 10.5281/zenodo.178227