The lace web spiders (Araneae, Phyxelididae) of Madagascar: phylogeny, biogeography and taxonomy
Author
Griswold, Charles E.
Author
Wood, Hannah Marie
Author
Carmichael, Anthea D.
text
Zoological Journal of the Linnean Society
2012
2012-03-20
164
4
728
810
http://dx.doi.org/10.1111/j.1096-3642.2011.00779.x
journal article
10.1111/j.1096-3642.2011.00779.x
0024-4082
5407022
AMBOHIMA VATO
SP. NOV
.
(
FIGS 6C
,
7C
,
14A–C
,
33A–C
,
36D, F
,
37D, F
,
43G–I
,
58
)
Types:
Holotype
male and
paratype
female (
CASENT9020002
) collected in montane rainforest at
1550 m
elevation in
Forêt d’Atsirakambiaty
,
7.6 km
285° WNW Itremo
,
20°35′36″ S
,
046°33′48″ E
,
Fianarantsoa Province
,
Madagascar
,
22–26 January 2003
,
C. Griswold
,
D. Silva
, and
J. J. Rafonomezantsoa
, deposited in
CASC
.
Etymology:
The specific name is from the Malagasy word for rock; a noun in apposition.
Diagnosis:
Male with palp as in
Figure 14A–C
, embolic base with a raised, distal cone, cymbium small, cymbium length less than 0.75 times carapace length; palpal tibial prolateral hook short and broad. The cymbial length of
A. vato
overlaps with that of some
A. sublima
specimens from
Fianarantsoa Province
, but males of
A. vato
may be distinguished by their smaller size and shorter legs, femur I length less than 2.5 times carapace length (compare
Fig. 6C
with 6F). Female vulva as in
Figures 33B
and
37D, F
, base bilobed, anteriorly with three or fewer tight, transverse coils.
Note:
Individuals from the Itremo massif resemble
A. sublima
in male and female genitalia such that diagnosis is difficult. The molecular phylogeny places these in a species group distant from
A. sublima
so that we describe the new species
A. vato
to accommodate the Itremo population.
Male (
Holotype
):
Total length 6.70. Markings similar to
Figure 6C
. Carapace 3.10 long, 2.40 wide; thoracic fovea 0.60 long, length 0.19 carapace; clypeus 0.28 high; ocular area 0.37 long, 0.89 wide; ratio of eyes AM/AL/PM/PL, 1.06:2.40:1.26:1.00, diameter of PM 0.19. Chelicerae 1.32 long, slender, smooth, promargin of fang furrow with six teeth, retromargin with four large and one minute teeth. Sternum 1.94 long, 1.64 wide; labium 0.74 long, 0.64 wide; palpal coxa 1.26 long, 0.50 wide. Legs elongate, femur I length 2.29 times carapace length; metatarsi I and II prolateral concavity and clasping spines as in
Figure 43G–I
, segment slightly swollen basad of cavity. Leg measurements (femur + patella + tibia + metatarsus + tarsus = [total]): I: 7.10 + 1.45 + 7.50 + 7.40 + 2.75 = [26.20]; II: 5.90 + 1.25 + 5.65 + 5.50 + 2.75 = [21.05]; III: 5.00 + 1.15 + 4.15 + 4.65 + 1.95 = [16.90]; IV: 6.40 + 1.25 + 6.05 + 6.70 + 2.45 = [22.85]; palp: 1.65 + 0.55 + 0.55 + (absent) + 1.95 = [4.70]. Palpal femur with probasal row of four thorn-like setae; tibia with dorsal blade (DTA) hatchet-shaped, prolateral hook (PTA) slender, blunt-tipped; cymbium length 1.80 times width, 0.63 length of carapace; palpal bulb as in
Figure 14A–C
, length 1.75 times width, embolus base with raised cone, reservoir course in embolus base strongly sinuate, space between embolus base and proximal embolic curve 1.15 times embolus base width.
Variation (N = 3):
Total length 5.30–6.70; carapace length 1.26–1.29 times width, height 0.28–0.33 times width; PER width 2.22–2.54 times OAL; OQP 0.91– 1.12 times OQA; cheliceral length 4.71–5.00 times clypeal height; retromargin of fang furrow with 5–6 teeth; sternum length 1.18–1.27 times width; femur I length 1.98–2.29 times carapace length; metatarsus I 1.76–2.39 times carapace length; cymbium length 0.63–0.73 times carapace length.
Female (
Paratype
):
Total length 8.20. Markings as in
Figure 7C
. Carapace 3.50 long, 2.65 wide; thoracic fovea length 0.17 times that of carapace; clypeus 0.28 high; ocular area 0.42 long, 1.13 wide; ratio of eyes AM/AL/PM/PL, 1.33:2.73:1.13:1.00, diameter of PM 0.17. Chelicerae 1.42 long, robust, smooth, promargin of fang furrow with six teeth, retromargin with five teeth. Sternum 1.84 long, 1.48 wide; labium 0.72 long, 0.64 wide; palpal coxa 1.20 long, 0.54 wide. Femur I length 1.75 times carapace length. Palpal femur with four anterobasal thorns. Calamistrum origin at 0.50 from metatarsus base, length 0.30 that of segment. Leg measurements (femur + patella + tibia + metatarsus + tarsus = [total]): I: 6.10 + 1.60 + 5.95 + 5.00 + 2.40 = [21.05]; II: 4.95 + 1.40 + 4.05 + 4.00 + 1.95 = [16.35]; III: 4.05 + 1.20 + 3.10 + 3.30 + 1.70 = [13.35]; IV: 5.15 + 1.30 + 4.40 + 4.50 + 1.90 = [17.25]; palp: 1.55 + 0.60 + 0.85 + (absent) + 1.85 = [4.85]. Epigynum as in
Figure 36D
; vulva as in
Figure 37D
, spermatheca with bilobed basal chamber and three tight distal spirals.
Variation (N = 4):
Total length 6.30–8.20; carapace length 1.32–1.44 times width, height 0.34–0.42 times width; PER width 2.53–3.05 times OAL; OQP 1.10– 1.34 times OQA; cheliceral length 4.56–5.25 times clypeal height; pro- and retromargins of fang furrow with 5–7 teeth; sternum length 1.13–1.24 times width; femur I length 1.59–1.74 times carapace length; metatarsus I 1.43–1.54 times carapace length; epigyna as in
Figures 33A
and
36D, F
, vulvae as in
Figures 33B
and
37D, F
.
Natural history:
Spiders were collected in montane rainforest, where they make typical
Ambohima
webs, similar to
Figure 2A
, beneath bark or fallen objects on the ground.
Distribution:
Known only from the
type
locality in a mountainous region of south-central
Madagascar
(
Fig. 58
).
Material Examined:
MADAGASCAR
:
Fianarantsoa Prov.
,
Forêt d’Atsirakambiaty
,
7.6 km
285° WNW Itremo
, elev.
1550 m
,
20°35′36″S
,
046°33′48″E
, montane rain forest,
22–26 January 2003
,
C. Griswold
,
D. Silva
and
J. J. Rafonomezantsoa
,
1 ♂
holotype
,
1 ♀
paratype
(
CASENT9020002
), web in base of fallen palm frond,
1 ♀
,
CASC
(
CASENT9005810
), together in web in fallen palm frond,
1 ♂
,
1 ♀
,
CASC
(
CASENT9005809
),
3 ♂
4 ♀
,
CASC
(
CASENT9005936
,
9017395
,
9020003
,
9017304
,
9005975
,
9016756
,
9005552
)
.