Systematics of the Australian spiny trapdoor spiders of the genus Blakistonia Hogg (Araneae: Idiopidae)
Author
Harrison, Sophie E.
Author
Rix, Michael G.
Author
Harvey, Mark S.
Author
Austin, Andrew D.
text
Zootaxa
2018
2018-11-12
4518
1
1
76
journal article
27975
10.11646/zootaxa.4518.1.1
ba2bd1cd-8a6f-4a94-93a2-96b99318a8b4
1175-5326
2609500
708981EF-21DC-4DC2-B1CD-8CFF4373DA8C
Blakistonia bassi
sp. n.
(
Fig. 7
A–I)
Type material.
AUSTRALIA
:
South Australia
:
Holotype
female, off
Pound Road
,
Ashton
,
Mount Lofty Ranges
,,
34°55’55.608”S
,
138°44’49.667”E
,
22 December 2014
, hand collected from mossy roadside bank,
S.E. Harrison
,
M. Harrison
(SAM
NN29619
DNA
).
Paratypes
:
2 females
, same data as holotype except
13 May 2016
,
S.E. Harrison
,
N. Birks
(
SAM
NN28529
,
NN28530
)
.
Diagnosis.
Females of
B
.
bassi
can be distinguished from all other species of
Blakistonia
by the fine, golden hairs that cover the carapace (
Fig. 7A, D
). Males are unknown.
All life stages of
B. bassi
can also be distinguished from those of other species with sequence data by the following nucleotide substitutions (
n
=
1 specimen
): G(3), C(87), C(102), T(111), G(199), C(205), T(207), T(255), C(339), A(390), C(462), C(479), C(481), G(546), G(573), G(591); and by the following unique molecular motifs: TT(30–31), GAC(66–68), GCT(367–369), AAG(372–374), GG(432–433), TGC(456–458), TGGA (468–471).
Description.
Holotype
female
(SAM NN29619): Medium-sized idiopid spider (total length 18.5).
Colour
(in ethanol;
Fig. 7
A–C): Carapace, legs and pedipalp dark red-brown, darker around fovea and lateral margins of caput, with darkened line from fovea to eye group (
Fig. 7A
); sternum, labium and maxillae uniformly golden-brown, chelicerae dark red-brown (
Fig. 7E, F
); abdomen dark brown with indistinct mottled chevron pattern (
Fig. 7A, C
).
Cephalothorax
: Carapace 7.8 long, 7.2 wide, 6.3 high, 1.1 times longer than wide; oval (
Fig. 7A
), caput high, ocular area flat (
Fig. 7C
); cuticle smooth, with pits outward from fovea and both sides of caput, and also two diagonally inward-facing indentations posteriorly; fovea procurved; two indistinct parallel rows of setae from fovea to eye group, less noticeabe both sideson both sides of caput; smaller fine setae also scattered across carapace, concentrated and form fringe around lateral margins; one long seta in fovea; median clump of thickened setae on clypeus (
Fig. 7D
); carapace with fine cover of thin golden hairs (
Fig. 7A, D
). Length of median clypeus less than 1.0; anterior margin slightly convex. Eye group 1.6 wide, 1.1 long, 0.2 of carapace width; anterior eye row strongly procurved; PLE–PLE/ALE–ALE ratio 1.1; posterior eye row slightly recurved; AME about equal in size to ALE and separated by twice diameter of ALE/AME; ALE and PLE separated by just over ALE diameter; PME similar in size to ALE/AME and about half size of PLE, and separated from PLE by about its own diameter (
Fig. 7D
). Labium without cuspules (
Fig. 7F
). Sternum 5.0 long, 3.3 wide, evenly setose with setae becoming longer towards anterior margin. Maxillae with
ca
. 35 cuspules on both sides (
Fig. 7E, F
).
Legs
: moderately setose and diffusely spinose; distinct upright setae on distal metatarsi I, II; femora I, II, and pedipalp laterally bowed; tarsi and metatarsi I, II and palpal tarsi scopulate (
Fig. 7
G–I). Paired tarsal claws with 1 row of ventral teeth: leg I p2 (1 large, 1 small) r1 (1 large, 1 small); leg II p2 (1 large, 1 small), r2 (1 large, 2 small); right leg III p2 (2 large), r1 (1 large); right leg IV p2 (1 large, 1 small), r1 (1 large); median tarsal claw without teeth. Pedipalp claw with 1 large and 1 small tooth.
Spination
: Leg I: tibia p3, r4; metatarsus p2, r5; tarsus with patch of 5 short spines scattered over ventral surface (
Fig. 7G, H
). Leg II: tibia p4, r4; metatarsus p4, r5; tarsus with patch of 3 short spines ventrally. Right leg III: patella p3; tibia p3, r3; metatarsus p12, r8; tarsus with patch of 8 spines scattered ventrally. Right leg IV: metatarsus p10, r6; tarsus with
ca
. 20 short spines scattered ventrally. Palp: patella p1, tibia p8, r6; tarsus p1, r1.
Leg and pedipalp measurements
: Length of legs IV> II> I> III. Leg I: femur 4.3, patella 3.1, tibia 2.7, metatarsus 2.1, tarsus 1.7, total = 13.9. Leg II: femur 4.2, patella 3.1, tibia 2.6, metatarsus 1.9, total = 14.9. Leg IV (right): femur 5.5, patella 3.9, tibia 4.0, metatarsus 3.7, tarsus 2.2, total = 19.3. Pedipalp: femur 4, patella 2.2, tibia 2.1, tarsus 2.5, total = 10.8.
Abdomen
: Setose, oval, one pair of very small, faint, unsclerotised dorsal sigilla; 10.7 long, 7.3 wide (
Fig. 7A
).
Genitalia
: Spermathecae paired, simple, unbranched, stout and outward facing, oval-shaped with lobe on anterior end, covered in opaque, mottled brown nodules (
Fig.
7I
).
Variation (n=3):
Carapace 7.8–9.0 long, 6.0–8.0 wide, no labial cuspules. Spination: Leg I: tibia p3–4, r4; metatarsus p2–3, r3–5; tarsus with 3–6 spines ventrally. Leg II: tibia p3–4, r4; metatarsus p4, r4–5; tarsus with 3–4 spines ventrally. Leg III: patella p2–3; tibia p0–3; r2–3; metatarsus p6–13, r6–8; tarsus with 8–13 spines ventrally. Leg IV: metatarsus p8–12, r3–6; tarsus with 10–20 spines ventrally. Pedipalp patella p1–2; tibia p7–8, r4–6; tarsus p1, r1–2.
Etymology.
This species is named in honour of Daniel Bass, for his unwavering support of this research.
Distribution.
Blakistonia bassi
is known from only a single roadside cutting at Ashton in the Mount Lofty Ranges, (
Fig. 31
). A number of active burrows were found in 2017; however, the species has not been found elsewhere in the Mount Lofty Range despite extensive historical collection, and was not discovered anywhere else as part of this project.
Remarks.
The burrow (
Fig. 2D, E
) is similar to that of
Idiosoma
in its thin, cryptic, flap-like nature, and certainly different to the D-shaped, plug-like burrow typical of
B. aurea
. All burrows found were adorned with moss and cryptic in appearance (
Fig. 2D, E
).