Blakistonia bassi Harrison & Rix & Harvey & Austin 2018, sp. n.
Creators: name: Harrison, Sophie E.
name: Rix, Michael G.
name: Harvey, Mark S.
name: Austin, Andrew D.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Idiopidae
Blakistonia
Blakistonia bassi

description: 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).
description: Published as part of Harrison, Sophie E., Rix, Michael G., Harvey, Mark S. & Austin, Andrew D., 2018, Systematics of the Australian spiny trapdoor spiders of the genus Blakistonia Hogg (Araneae: Idiopidae), pp. 1-76 in Zootaxa 4518 (1) on pages 27-28, DOI: 10.11646/zootaxa.4518.1.1, http://zenodo.org/record/2609500