Ariadna amabilia 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 amabilia

description: Ariadna amabilia sp. nov.
Figs 8a–h, 9a–c, 10a–h, 11a–b, 12
http://zoobank.org/NomenclaturalActs/c2702949-d830-4fea-bf7f-d35d51dbad7d
Type material. Holotype ♂. AUSTRALIA: Tasmania: Cornelian Bay, 42.27 °S, 145.83°E, in burrow in bank, coll. V. V. Hickman, 28 August 1930 (AM KS.131051).
Paratype ♀. Same data as holotype (AM KS.131052).
Other material examined. 4 ♀, same data as holotype (AM KS.29199); 1 ♀, same data as holotype, except 28 February 1964 (AM KS.29200); 6 ♀, Hobart, 42.88°S, 147.31°E, 18 May 1948, V. V. Hickman (AM KS.29194); 3 ♀, Cascades, 42.89°S, 147.27°E, 28 May 1929, V. V. Hickman (AM KS.29203); 1 ♀, Kingston Beach, 42.98°S, 147.32°E, in holes in bank, 5 January 1945, V. V. Hickman (AM KS.29207); 1 ♀, Trevallyn, Launceston, 41.44°S, 147.10°E, 10 April 1928, V. V. Hickman (AM KS.29208); 1 ♀, Porter Hill, 42.92°S, 147.35°E, 2010, coll. R. Raven (TMAG J4123).
Etymology. The specific epithet is a Latin adjective, meaning ‘lovely’ and refers to the pleasing form and colouration of this species.
Diagnosis. Ariadna amabilia sp. nov. is closest to A. alta sp. nov., A. segmentata and A. thylacinus sp. nov. It is differentiated from A. alta sp. nov. by the lack of a dual row of macrosetae proventrally on tibia I of females (Fig. 10f, g cf. Fig. 5f, g). It can be differentiated from A. segmentata by the overall shape of the pedipalp bulb, with a rounded square bulb which on lateral view is distinctly bulbous dorsally in A. amabilia sp. nov., but is elongate globular shaped in A. segmentata, and by the length and curvature of the embolus, which is elongate, smoothly curved and hooked in the apical portion in A. amabilia sp. nov., but is relatively broad and hooked at around the midpoint in A. segmentata (Fig. 9a–c cf. Fig 27a–c). The species can be distinguished from A. thylacinus sp. nov. by the sinuous apical section of the embolus, which is smoothly curved and hooked apically in A. amabilia sp. nov., whereas in A. thylacinus sp. nov. the embolus is sinuous apically; it can further be distinguished by the embolus arising from the bulb smoothly from the ventral edge of the bulb in A. amabilia sp. nov., whereas in A. thylacinus sp. nov. the basal section of the embolus arises from a distinct mound (Fig. 9a–c cf. Fig. 35a–c).
Description. ♂ (based on holotype; AM KS.131051). Total length 8.5.
Colour in ethanol: Carapace dark red brown, lateral edges darker brown, darker areas extending out from fovea, re-bordered, sparse dark setae denser to edges and anteriorly; sternum dark orange brown, with darker brown areas running from between coxae to middle, sparse brown setae; labium dark brown, maxillae orange brown, chelicerae dark red brown; abdomen dorsally cream, with 10 dark grey transverse markings. Legs golden brown and covered in orange-brown setae (Fig. 8a–h).
Cephalothorax: 3.8 long, 2.6 wide. Carapace rounded oval, narrowing anteriorly, edges gently undulating, fovea a shallow indentation (Fig. 8a); from lateral view carapace domed, highest just posterior to eyes (Fig. 8c). Labium narrowed anteriorly, about ¾ length of maxillae; chelicerae semi-porrect, with basal transverse ridge, retromargin with single tooth, promargin with three teeth; sternum elongated oval with precoxal triangles and with smaller, broadly triangular intercoxal extensions (Fig. 8b). Posterior eye row slightly recurved, eye group occupying about a half of carapace width (Fig. 8d).
Abdomen: 4.7 long. Rounded oval, with scattered fine setae (Fig. 8a).
Legs: Leg length ratio: II>I>III>IV. Leg I femur 3.2, patella 1.2, tibia 2.6, metatarsus 2.9, tarsus 1.1. Leg II femur 3.2, patella 1.1, tibia 3.2, metatarsus 3.2, tarsus 1.2. Leg III femur 2.8, patella 1.0, tibia 2.0, metatarsus 2.3, tarsus 1.2. Leg IV femur 2.6, patella 0.8, tibia 2.1, metatarsus 2.2, tarsus 1.1. Femur I bowed in dorsal view. Leg I Femur d1-1ap, dp2ap; tibia p1-1-1-1-1, pv1-1-1-1-1ap, rv1-1-1-1-2-1ap, r1-1-1-1-1-1; metatarsus p1, pv1-1-1-1-1, rv1-1-1-1-1ap, r1; Leg II femur d1-1, dp2ap; tibia p1-2-1, pv1ap, rv1-1-2-1-1-1ap, r1-1; metatarsus pr2-1-1-1-1ap, rv1-1-1-1, r1. Leg IV d1-1-1-1, dp1ap, p1, pv1-1-1ap, rv1; metatarsus v1, rv1-1-1-1-1ap, r1-1ap. Retrolateral distal preening comb with 7 spines (Fig. 8e). STC I, II with 10 teeth, ITC with small tooth. Tarsi with sparse, distal ventral scopulose setae.
Pedipalp: tibia not inflated, 1.5 times length of cymbium; cymbium rounded rectangular, with pronounced anterior prolateral extension; bulb rounded square in lateral view, with a bulbous projection dorsally, embolus arising ventrally from bulb, elongate, thin, hooked apically (Fig. 9a–c).
Description. ♀ (based on paratype; AM KS.131052). Total length 10.3.
Colour in ethanol: Carapace red brown, darker anteriorly, pale area centrally demarking raised caput, beginning anteriorly of fovea, edges darker red brown; sparse scattered setae, denser anteriorly; sternum pale orange, darker at edges, covered with moderately long black setae, labium darker red brown, maxillae orange brown, paler apically, chelicerae dark brown with dense, long, brown setae, abdomen dorsally pale cream-grey, with nine dark transverse markings, ventrally uniform pale-cream grey, excepting dark grey around the spinnerets. Legs golden brown with patches of dark brown on legs I and II, all with covering of fine setae (Fig. 10a–h).
Cephalothorax: 4.6 long, 2.8 wide, 2.9 high. Carapace oval, with broad, square ‘neck’ anteriorly, anterior edge broadly convex (Fig. 10a); lateral profile domed, highest between fovea and eye group (Fig. 10c). Labium narrowed anteriorly, about ¾ length of maxillae; chelicerae robust with basal transverse ridge, retromargin with single tooth, promargin with three teeth; sternum elongated oval with precoxal triangles and with smaller, rounded intercoxal extensions (Fig. 10b). Posterior eye row slightly recurved, eyes occupying about 0.4 of carapace width (Fig. 10d).
Abdomen: 5.7 long, rounded oval (Fig. 10a).
Legs: Leg length ratio II>I>IV>III. Leg I femur 3.1, patella 1.3, tibia 2.4, metatarsus 2.2; tarsus 0.9; leg II femur 3.1, patella 1.5, tibia 2.8, metatarsus 2.9, tarsus 1.1; leg III femur 2.6, patella 1.1, tibia 1.3, metatarsus 1.8, tarsus 1.1; leg IV femur 2.6, patella 1.4, tibia 2.2, metatarsus 1.7, tarsus 0.7. Femur I bowed in dorsal view. Macrosetae: Leg I Femur dp2ap; tibia pv1-1-1-1-1ap, rv1-1-1-1-1ap; metatarsus 2-2-2-1-2-2ap. Leg II femur dp1ap, tibia p1, pv1ap; rv1-1-1-1ap; metatarsus pv1-1-2-1-1ap, rv1-1-1-1-1. Leg IV femur d1-1-1-1, tibia pv1ap, v1-1; metatarsus pv1ap, rv1-1-1-1ap. Retrolateral distal preening comb with 7 spines (Fig. 10e). STC I, II with 11 teeth, ITC with small tooth. Tarsi with distal ventral scopulose setae.
Pedipalp: With dense setae, dense macrosetae clustered prolaterally on tibia and tarsus, pedipalp claw bare.
Genitalia: Anterior receptaculum simple and gently sinuous in ventral view, in lateral view sinuous with three or four defined finger-like projections apically (Fig. 11a–b).
Variation. Specimens examined were consistent in colour and form of transverse abdominal markings and showed little variation in size. Leg macrosetae of tibia and metatarsus I varied little in number between specimens.
Distribution. Known from locations across Tasmania (Fig. 12).
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 162-167, DOI: 10.11646/zootaxa.5105.2.1, http://zenodo.org/record/6332569