Ariadna alta Marsh & Stevens & Framenau 2022, sp. nov.
Creators: name: Marsh, Jessica R.
name: Stevens, Mark I.
name: Framenau, Volker W.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Segestriidae
Ariadna
Ariadna alta

description: Ariadna alta sp. nov.
Figs 5, 6a–h, 7a–b
http://zoobank.org/NomenclaturalActs/dbcc5fdd-bee0-444a-87eb-5d01fa0f19cf
Type material. Holotype ♀. AUSTRALIA: Tasmania: Frenchman’s Cap Track, west Tasmania, 42.27 °S, 145.83°E, under log/bark, Nothofagus forest, coll. L.J. Boutin, 26 December 1997 (QVMAG QVM.13.24065).
Other material examined. AUSTRALIA: Tasmania: 1 ♀ Frenchman’s Cap, coll. B. McCausland, April 1980 (QVMAG QVM:2020:13:0106); 1 ♀, Evercreech Forest Reserve, 41.421667°S, 148.08111°E, coll. L.J. Boutin, 24 June 2003 (QVMAG QVM:2020:13:0115); 3 ♀, Mount Hobbs, 42.50°S, 147.59°E, V. V. Hickman, 15 May 1928 (AM KS.29180).
Etymology. The specific epithet is a Latin adjective, meaning ‘high’ and refers to the elevation of the known localities.
Diagnosis. Ariadna alta sp. nov. is most similar to A. amabilia sp. nov., A. segmentata and A. thylacinus sp. nov. It can be differentiated from these by the presence of a proventral dual row of macrosetae on tibia I of females (Fig. 6f, 6g cf. Figs 10f, g; 28f, g; 36f, g); by the elevated, domed cephalothorax, being highest just posterior to the eye group (Fig. 6c cf. Figs 10c, 28c, 36c) and by the female genitalia, with the anterior receptaculum having three or four distinct anterior projections (Fig. 7a–b cf. Figs 11a–b, 29a–b; 37a–b). Ariadna alta sp. nov. has been recorded from the type locality of A. major Hickman 1929, Mount Hobbs, SE Tasmania. It is clearly distinguished from A. major by the presence of transverse abdominal chevrons in A. alta sp. nov. (Fig. 6a), by the leg length ratio, which is II>I>III>IV in A. alta sp. nov., but is I>II>IV>III in A. major and by the overall larger size of A. major, which is 16mm long, as opposed to 10.8mm in A. alta sp. nov.
Description. ♀ (based on holotype; QVMAG QVM.13.24065). Total length 10.8.
Colour in ethanol: Carapace dark, reddish brown, darker around edges, with a pale area centrally demarking raised caput, beginning anteriorly of fovea and bordered by darker red brown; darkened median line running from fovea anteriorly and extending to between half distance of fovea to eye group. Sparse scattered setae, denser towards lateral edges and anteriorly. Sternum red-brown, with moderately long, scattered dark setae; labium darker brown, paler apically; maxillae orange brown, paler apically; chelicerae dark brown with dense, long, black setae. Abdomen with metallic sheen, dorsally grey, with faint paler, not well-defined chevrons; ventrally grey with mottled paler cream patches; book lungs yellow cream. Legs red brown, covered with setae (Fig. 6a–c).
Cephalothorax: 5.4 long, 3.3 wide, 3.6 high. Carapace rounded rectangular, with broad, square ‘neck’ anteriorly, anterior edge convex, posteriorly with defined median indent, fovea a shallow slit (Fig. 6a); lateral profile domed, highest point at fovea (Fig. 6c). Labium narrowed anteriorly, about ¾ length of maxillae. Chelicerae broad, robust with basal transverse ridge, retromargin with single tooth, promargin with three teeth; sternum elongated oval with defined precoxal triangles and with rounded triangular intercoxal extensions (Fig. 6b). Eye group 0.6 wide, 0.5 of the width of the anterior carapace; posterior eye row slightly recurved, eyes small, three pairs of eyes widely separated (Fig. 6d).
Abdomen: 5.6 long. Covered in fine dense setae (Fig. 6a).
Legs: Leg length ratio: II>I>III>IV. Leg I femur 3.1, patella 1.6, tibia 2.9, metatarsus 2.0, tarsus 0.7. Leg II femur 2.8, patella 1.7, tibia 2.8, metatarsus 2.3, tarsus 0.8. Leg III femur 2.4, patella 1.7, tibia 2.8, metatarsus 2.4, tarsus 0.9. Leg IV femur 2.9, patella 1.6, tibia 2.5, metatarsus 2.1, tarsus 1.0. Femur I bowed in dorsal view. Macrosetae: Leg I femur dp2ap; tibia pv1, v2-2-2, pv1, rv1, v2, pv1, v2ap; metatarsus pv1-1-1, v2-2-2-2-2-1-2ap, rv1. Leg II femur dp1ap; tibia p1-2, pv1ap, rv1-1-1-1-1ap; metatarsus 2-2-1-2-1-2-1-2ap. Leg IV femur d1-1; tibia p1ap, v1-1/0; metatarsus rv1-1-1-1ap. Retrolateral distal preening comb with 8 macrosetae with two long macrosetae adjacent (Fig. 6e). STC I, II with 9 teeth, ITC with small tooth. Tarsi with distal ventral scopulae.
Pedipalp: Pedipalp with single, toothless claw. Tarsi and tibia with dense clusters of proventral macrosetae. Tarsi scopulate.
Genitalia: Anterior receptaculum bilobed, with several finger-like projections in the mid-point and apically (Fig. 7a–b).
Variation. Specimens examined were consistent in colour and form of transverse abdominal markings and showed little variation in size. Pattern and number of macrosetae were consistent for tibia and metatarsus I.
Distribution. Known from locations across Tasmania (Fig. 5).
description: Published as part of Marsh, Jessica R., Stevens, Mark I. & Framenau, Volker W., 2022, A taxonomic revision of the tube-web spiders of the genus Ariadna (Araneae: Segestriidae) in Tasmania, pp. 151-201 in Zootaxa 5105 (2) on pages 159-162, DOI: 10.11646/zootaxa.5105.2.1, http://zenodo.org/record/6332569