A revision of the Neotropical spider genus Oligoxystre Vellard 1924 (Theraphosidae, Ischnocolinae)
Author
Guadanucci, José Paulo Leite
text
Zootaxa
2007
1555
1
20
journal article
10.5281/zenodo.178227
0088f909-2c33-4a47-a180-1d5835cf127a
1175-5326
178227
Oligoxystre bolivianum
Vol 2001
n. comb.
(
Figures 1–12
)
Pseudoligoxystre bolivianum
Vol 2001
: 3
, f. 1–7.
Types
.
Holotype
male and
paratypes
male and subadult, Samaipata, Santa Cruz,
Bolivia
, Universidad Rene Moreno de Santa Cruz, Museo de Historia Natural "Noel Kempff Mercado",
Bolivia
, not available for loan.
FIGURES 1–6.
Oligoxystre bolivianum
.
1–4. Male MZSP 26076. 1. Tibial apophysis, ventral-prolateral view. 2. Bulb, retrolateral view. 3. Bulb, prolateral view. 4. Bulb, dorsal view. 5. Male, embolus tip. 6. Female, MZSP 23224, spermathecae, dorsal view. Scale = 1mm.
Note
.
Vol (2001)
established
Pseudoligoxystre
by comparing his material to a species then placed in
Oligoxystre
(
O. argentineniense
)
and observed the following differences: embolus shorter, tarsi longer and each spermathecal receptacle bearing two apical lobes. According to Vol,
Oligoxystre
has a long and thin embolus and the spermethecae formed by two long tubes bearing a rounded termini. The name
Pseudoligoxystre
comes from the resemblance that it has with
Oligoxystre
, because they both have a labium wider than long with few cuspules (fewer than 10). However, when Vol described
Pseudoligoxystre
, the only material available to him for comparison was
O. argentinense
, which has since been transferred to
Catumuri
. It is clear that Vol used
O. argentinense
to differ his new genus when he mentions that the genus
Oligoxystre
presents the palpal bulb and spermathecae as described above.
FIGURES 7–8.
Oligoxystre bolivianum
. 7. Female MZSP 23224, from Catalão, Goiás, Brazil (photo: J. Guadanucci). 8. Male MZSP 26076, from Catalão, Goiás, Brazil (photo: H. Mariano).
Guadanucci (2004)
described
Catumiri
for
Oligoxystre argentinense
and three new species. According to his description
Catumiri
differs from
Oligoxystre
by the divided anterior tarsal scopula, spermathecae receptacles each with one apical terminus; presence of a row of teeth on the prolateral margin of the tarsal claws of males. According to
Vellard (1924)
,
Oligoxystre
is characterized by the labium wider than long with 4 or 5 cuspules; maxilae with 15–20 cuspules; tarsal scopula I and II undivided; metatarsus I occupied by scopula until the 1/3 basal region and II more than apical half occupied by scopula, matching perfectly with Vol`s description of
Pseudoligoxystre
. It was not possible to have access to the type-material. Males from the typelocality (MZSP 26082, 26083) that match Vol's descritpion were examined.
Concluding, Vol erroneously used
Catumiri argentinense
(instead of the description of the
type
species) to compare and establish
Pseudoligoxystre
, ignoring Vellard`s description of
Oligoxystre
.
Catumiri
comprises a different group from
Oligoxystre
, as described as a new genus by
Guadanucci (2004)
. Therefore,
Pseudoligoxystre
is considered here junior synonym of
Oligoxystre
.
FIGURES 9–10.
Oligoxystre bolivianum
. 9. Female, from Samaipata, Santa Cruz, Bolívia. 10. Spiderling, from Rurrenabaque, Beni, Bolívia (photos: J. Guadanucci).
Material examined
.
BOLIVIA
. Santa Cruz: Samaipata, 2ɗ (
MZSP
26082, 26083); Beni: San Buenaventura, 2ɗ (
MZSP
26084, 26086), 1Ψ (
MZSP
26085).
BRAZIL
. Distrito Federal:
Brasília
, 4Ψ (
MNRJ
), 3Ψ and 1ɗ (
MNRJ
), 1ɗ (UnB 870), 1ɗ (UnB 131), 1Ψ (UnB 343), 1Ψ (UnB 765), 1ɗ (UnB 1129), 1Ψ (UnB 1645); Sobradinho, 1Ψ (UnB 1795), 1ɗ (UnB 1824), 1ɗ (UnB 1910), 1Ψ (UnB 1993), 1Ψ (UnB 2099), 1ɗ (UnB 2604), 1ɗ (UnB 2752). Goiás: Aragarças, 1ɗ (
MNRJ
3850); Catalão: Fazenda Alvorada 1ɗ (
MZSP
26076), 1Ψ (
MZSP
23224), Mineiros, 1ɗ (
IBSP
9493). Mato Grosso: Chapada dos Guimarães, 1ɗ (
IBSP
9494), (
IBSP
9495), 1Ψ (
IBSP
9043), (
IBSP
9504), 1Ψ (
IBSP
9503), 1Ψ (
IBSP
9505), 1Ψ (
IBSP
9143), 1Ψ (
IBSP
9040), 1Ψ (
MZSP
18978); Cuiabá, 1ɗ (
IBSP
9496); Diamantina, 1ɗ (
IBSP
5686); Manso, 1ɗ (UnB 202), 1j (UnB 188). Rondônia: U. H. Samuel, Porto Velho, 1Ψ (
IBSP
9506).
Diagnosis
. Males may be distinguished from all other species by the palpal bulb with a short embolus with a small subapical keel (
Figs. 2–5
). Females may be distinguished by the spermathecal receptacula being as wide as long, with apical termini apical (
Fig. 6
).
FIGURES 11–12.
Oligoxystre bolivianum
. 11. Male, from Rurrenabaque, Beni, Bolívia. 12. Female, from Rurrenabaque, Beni, Bolívia (photos: J. Guadanucci).
FIGURES 13–14.
Collecting site of
Oligoxystre bolivianum
.
13. Landscape of Catalão, Goiás, Brazil. 14. Forest in Catalão, Goiás, Brazil (photos: A. Monteiro).
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-p1, patella 0, tibia (v) 0-0- 1, (p) 1-1-1; Legs:
I
: femur (d) 0-0-p1, patella 0, tibia (v) 2-2-ap1, (p) 0-1-0, metatarsus (v) r1-0-0;
II
: femur (d) 0-0-2, patella 0, tibia (v) 2-2-ap2, (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-ap2, (p) 1-1-0, metatarsus (r) 1-1-0, (v) 0-2-ap3, (p)1-1-1;
IV
: femur (d) 1-5-3, patella 0, tibia (r) 1-1-1, (v) 3-3-ap3, (p) 0-1-1, metatarsus (r) 1-1-1, (v) 2-0-ap3, (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
).
FIGURES 15–16.
Collecting site of
Oligoxystre bolivianum
. 15. Landscape of Samaipata, Santa Cruz, Bolívia. 16. Collecting site in Samaipata, Santa Cruz, Bolívia (photos: D. Weinmann).
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-p1, patella 0, tibia (v) 0-2-ap2, (p) 0-1-0. Legs
I
: femur (d) 0-0-p1, patella 0, tibia (v) 0-1-ap1, (p) 0-1-0, metatarsus (v) r1-0-0.
II
: femur (d) 0-0-p1, patella 0, tibia (v) 0-1-ap1, (p) 0-1-0, metatarsus (v) r1-0-0.
III
: femur (d) 0-0-1, patella 0, tibia (r) 1-1-0, (v) 0-2-ap2, (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-ap2, metatarsus (r) 0-1-1, (v) p1-4-ap3, (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.
FIGURES 17–18.
Collecting site of
Oligoxystre bolivianum
. 17. Landscape in Rurrenabaque, Beni, Bolívia. 18. Collecting site in Rurrenabaque, Beni, Bolivia (photos: D. Weinmann).
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.