Ariadna abbreviata 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 abbreviata

description: Ariadna abbreviata sp. nov.
Figs 1a–h, 2 a-c, 3a-h, 4a–b, 5
http://zoobank.org/NomenclaturalActs/874d7db6-1113-4ef2-9750-dffe0411b9bc
Type material. Holotype ♂. AUSTRALIA: Tasmania: Domain, Hobart, 42.87°S, 147.33°E; 20 May 1948, J.L. & V. V. Hickman (AM KS.131055).
Paratype ♀. Same data as holotype (KS.131057).
Other material examined. Tasmania: 3 ♂, 1 ♀, Domain, Hobart, 42.87°S, 147.33°E, 31 Aug 1942, V. V. Hickman (AM KS.29193); 17 ♂, 10 ♀, same locality, 20 May 1948, V. V. Hickman (AM KS.29196); 1 #m, Mount Rumney, 42.85°S, 147.44°E, 6 June 1963, J.L. & V. V. Hickman (AM KS.29175).
Etymology. The specific epithet is a Latin adjective, meaning ‘shortened’, and refers to the row of three shortened and blunt macrosetae, prolaterally on metatarsus I of this species.
Diagnosis. Ariadna abbreviata sp. nov. is closest to A. burchelli, A. clavata, A. fragilis sp. nov. and A. tigrina sp. nov. It can be differentiated from A. burchelli by the presence of macrosetae on tibia of females (Fig. 3f, g, h cf. plate 8, fig. 4, Hogg 1900); from A. clavata, A. fragilis sp. nov. and A. tigrina sp. nov. by the presence of a row of three short and blunt prolateral macrosetae apically on metatarsus I of males, which are around 1/3 the length of the other macrosetae on metatarsus I (Fig. 1f, g cf. Figs 20f, g, 37f, g).
Description. ♂ (based on holotype; AM KS.131055). Total length 5.0.
Colour in ethanol: Carapace dark red-brown, with scattered sparse brown setae, border a darker brown; sternum orange brown, with regular darker inter-coxal patches; sparse, scattered long dark setae, denser around edges, labium, maxillae and chelicerae darker orange brown; abdomen dorsally with about nine dark grey, clearly defined chevrons, interspersed with pale cream; abdomen ventrally pale cream, with dark grey median band. Legs golden brown, with sparse dark setae (Fig. 1a–c).
Cephalothorax: 2.4 long, 1.7 wide, 1.4 high. Carapace oval, narrower anteriorly, edges gently undulating, fovea a shallow indentation (Fig. 1a), from lateral view carapace gently domed, highest near fovea (Fig. 1c). Labium narrowed anteriorly, about ¾ length of maxillae; chelicerae with basal transverse ridge, retromargin with single tooth, promargin with three teeth; sternum oval, with precoxal triangles and with smaller, broadly triangular intercoxal extensions (Fig. 1b). Eye group 0.6 wide; 0.5 of the width of the anterior carapace; posterior eye row slightly recurved (Fig. 1d).
Abdomen: 2.6 long. Covered in dense, golden-brown setae (Fig. 1b).
Legs: Leg length ratio I>II>IV>III. Leg I femur 1.6, patella 0.6, tibia 1.9, metatarsus 1.6, tarsus 0.6. Leg II femur 1.5, patella 0.5, tibia 2.0, metatarsus 1.3, tarsus 0.8. Leg III femur 1.5, patella 0.4, tibia 1.0, metatarsus 1.1, tarsus 0.6. Leg IV femur 1.9, patella 0.5, tibia 1.2, metatarsus 1.1, tarsus 0.5. Femur I bowed in dorsal view. Tarsus I slightly bowed ventrally in lateral view, broader at apex than at base; tarsi II – IV straight and same width for length. Metatarsus IV with prolateral row of three blunt and shortened macrosetae (around 1/3 of length of other macrosetae on metatarsus I) apically. Macrosetae: Leg I Femur dp2ap; tibia p1-1-1, pv1-1-1-1-1ap, rv1-1-1-1-1ap, r1-1-1; metatarsus v1, pv1-1(blunt)-1(blunt)-1(blunt), rv1-1(blunt)-1ap, r1. Leg II femur d1-1/0, dp1ap; tibia p1-1- 2, pv1ap, rv1-1-1ap, r1-1-1 (left); p1-1-2, pv1ap, rv1-1-1ap (right); metatarsus p1, pv1-1-1ap, rv1-1-1-1ap, r1 (left and right). Leg IV femur d1-1-1; tibia pv1ap, rv1-1, r1; metatarsus rv1-1-1-1ap. Retrolateral distal preening comb with 7 spines, of equal length (Fig. 1e). STC legs I, II with 9 teeth, ITC with long, thin tooth. Tarsi with sparse distal ventral scopulose setae.
Pedipalp: Pedipalp tibia about 0.7 width to length, cymbium with anterior prolateral extension, scopulose setae anteriorly; bulb large, globular in lateral view; embolus long, thin and hooked apically (Fig. 2a–c).
Description. ♀ (based on paratype; KS.131057). Total length 6.6.
Colour in ethanol: Carapace uniform reddish-brown, with fine darker line around edges; sparse scattered setae, denser towards around eye group; sternum orange brown, with moderately long black setae, denser towards edges; labium darker brown, paler apically; maxillae orange brown, paler apically; chelicerae darker red-brown with dense, long, black setae. Abdomen dorsally dark with eight dark grey, clearly defined chevrons, broader and connecting at midpoints and extending laterally and ventrally, interspersed with cream; ventrally cream with linear dark grey median line. Legs golden brown, legs I, II with dense setae, III, IV less dense (Fig. 3a–c).
Cephalothorax: 2.9 long, 1.8 wide, 1.7 high. Carapace oval, with broad, square ‘neck’ anteriorly, anterior edge straight, fovea a shallow indented pit (Fig. 3a); lateral profile domed, highest point just posterior to eye group (Fig. 3c). 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 precoxal triangles and with smaller, rounded intercoxal extensions (Fig. 3b). Eye group 0.6 wide; 0.5 of the width of the anterior carapace; posterior eye row slightly recurved (Fig. 3d).
Abdomen: 3.7 long. Covered in short, dense setae (Fig. 3a).
Legs: Leg length ratio I>IV>II>III. Leg I femur 1.8, patella 0.8, tibia 1.4, metatarsus 1.1, tarsus 0.5. Leg II femur 1.6, patella 0.7, tibia 1.0, metatarsus 0.8, tarsus 0.5. Leg III femur 1.2, patella 0.5, tibia 0.8, metatarsus 0.8, tarsus 0.5. Leg IV femur 1.6, patella 0.8, tibia 1.2, metatarsus 1.1, tarsus 0.6. Macrosetae: Leg I femur: dp1ap; tibia pv1-1-1/0-1ap, rv1-1-0/1-1ap; metatarsus v2-2-1-2-2. Leg II femur dp1ap; tibia rv1-1-1ap, pv1ap; metatarsus pv1, v2-2-2. Leg IV tibia pv1ap, v1-1-1; metatarsus pv1-1-1ap. Retrolateral distal preening comb with 7 spines (Fig. 3e). STC I, II with 9 teeth, ITC with small tooth. Tarsi with distal ventral setae.
Pedipalp: Dense clusters of macrosetae prolaterally on tarsus and tibia. Scopulose setae on tarsus.
Genitalia: Anterior receptaculum bilobed, in ventral view shape simple, with globular apex (Fig. 4a–b).
Variation. All males examined had a row of three short, blunt macrosetae prolaterally on metatarsus I. Specimens were consistent in colour and form of transverse abdominal markings and showed little variation in size.
Distribution. Known from the Hobart area, in the south-east of 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 155-159, DOI: 10.11646/zootaxa.5105.2.1, http://zenodo.org/record/6332569