Ariadna segmentata Simon 1893
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 segmentata

description: Ariadna segmentata Simon, 1893
Figs 26a–h, 27a–c, 28a–h, 29a–b, 30
Ariadna segmentata Simon, 1893: 306, Rainbow 1911: 136; Hickman 1967: 41, 63–65, pl. VII, fig. 3.
Type material. Holotype ♀. AUSTRALIA: Tasmania: Launceston, 41.44 S, 147.14 E, Simson leg. (MNHN AR16175). Only images examined.
Other material examined. AUSTRALIA: Tasmania: 1 ♂, Launceston, 41.45°S; 147.20°E (QVMAG QVM:13:42352); 1 ♀, Launceston, Panubra Street, 41.46650°S, 147.15290°E, 4 May 1972 (QVMAG QVM:2019:13:0223); 1 ♀, South Launceston, 41.46°S, 147.15°E (QVMAG QVM:2018:13:0419); 1 ♀ (QVMAG QVM:2020:13:0112); 1 ♀, no location (QVMAG QVM:13:42316); 1 ♀, Hadspen, 41.30°S, 147.05°E, L. McCommon, 11 July 1992 (QVMAG QVM:13:6345); 1 ♀, Bracknell, 41.65°S, 146.93°E, 15 February 1964 (QVMAG QVM:2020:13:0104); 1 ♂, Trevallyn, 41.44°S, 147.12°E, 16 October 1982 (QVMAG QVM:2020:13:0109); 1 ♂, Mount Field National Park, Russel Falls Walk, 42.67°S, 146.58°E, 14 January 2002 (QVMAG QVM:2020:13:0108); 1 ♂, Hobart, 42.88°S, 147.32°E, 30 July 1978 (TMAG J1362); 1 ♀, Port Davey, 42.28°S, 145.97°E (TMAG J1759); 1 ♀, west Hobart, 42.88°S, 147.33°E (TMAG J666); 1 ♀, New Town, 42.86°S, 147.30°E (TMAG J1425); 1 ♀, Bruny National Park, Bush Blitz expedition, 43.40°S, 147.28°E (TMAG J6271); 1 ♀, New Town, 42.86°S, 147.31°E, June 1948 (AM KS.29179); 1 ♀, Great Lake, 41.88°S, 146.71°E, 26 May 1964 (AM KS.29164); 1 ♀, Mount Wellington, 42.90°S, 147.24°E, 12 December 1956 (AM KS.29165); 1 ♂, Launceston, 41.44°S, 147.10°E (AM KS.29188); 1 ♀, Burnie, 41.05°S, 145.90°E (AM KS.2909).
Diagnosis. Ariadna segmentata is closest to A. alta sp. nov., A. amabilia sp. nov., and A. thylacinus sp. nov.. It is differentiated from these species by the presence of a longitudinal pale median mark anteriorly on the sternum (Fig. 26b, 28b cf. Figs 6b, 8b, 10b, 33b, 35b). It can further be differentiated from A. amabilia sp. nov. and A. thylacinus sp. nov., by the rounded oblong bulb, with a relatively short and thick embolus, which is bent from its midpoint and by the cymbium with a well-defined prolateral extension (Fig. 27a–c cf. Figs 9a–c, 35a–c), and from A. alta sp. nov. by the flatter, less domed carapace, when viewed laterally (Fig. 28b cf. Fig. 5c) and by the absence of a dual row of macrosetae prolaterally on tibia I (Fig. 28f, g cf. Fig. 5f, g). It can be distinguished from A. alta sp. nov. and A. amabilia sp. nov., by the form of the anterior receptaculum, which is unilobed and hooked apically (Fig. 29a–b cf. Figs 7a–b, 11a–b).
Description. ♂ (based on QVMAG QVM:13:42352). Total length 8.3.
Colour in ethanol: Carapace red brown, with sparse, scattered dark setae, denser towards edges; sternum red brown, with longitudinal pale line anteriorly, with sparse long black setae; maxillae and labium mid brown, paler in colour apically, chelicerae red brown; abdomen dorsally pale cream, with six dark grey chevrons, ventrally dark grey, with pale yellow book lungs, spinnerets pale yellow. red brown, with faint cream longitudinal patches dorsally and on joints (Fig. 26a–h).
Cephalothorax: 4.8 long, 2.7 wide, 1.9 high. Carapace elongated oblong, narrowed anteriorly, carapace flattened, highest just posterior to fovea (Fig. 26a, c); fovea shallow pit. Labium narrowed anteriorly, about ¾ length of maxillae; chelicerae hypognathous, 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. 26b). Eye group 0.93 wide, 0.54 of anterior carapace width. Posterior eye row straight, eye group on extensions projecting anteriorly over clypeus, eye group occupying about a half of carapace width.
Abdomen: 3.5 long; with sparse macrosetae (Fig. 26a).
Legs: Leg length ratio I>II>IV>III. Leg I femur 4.6, patella 1.7, tibia 4.2, metatarsus 4.1, tarsus 1.4. Leg II femur 4.1, patella 0.8, tibia 3.9, metatarsus 5.2, tarsus 1.4. Leg III femur 3.5, patella 0.7, tibia 2.1, metatarsus 2.8, tarsus 1.1. Leg IV femur 3.5, patella 1.5, tibia 2.9, metatarsus 3.5, tarsus 1.0. Femur I bowed in dorsal view. Macrosetae: Leg I femur d1ap, dp2ap; tibia p1-1-1-1-2, pv1-1-1-1ap, v1-1-1ap, rv1-1-1-1, r1-1-1-1-1-1; metatarsus pv2- 1-1, v1, rv2-1-1-1ap. Leg II femur d1-1, dp1ap; tibia p1-1-2, pv1-1ap, rv1-1-1-1ap, r1-1; metatarsus p2-1-2-1, pv1, rv1-1-1-1-1-1ap. Leg IV femur d1-1-1, dp1ap; tibia p1-1, pv1-1-1ap, rv1-1-1; metatarsus p1-1, rv1-1ap, r1-2-2-1ap. Retrolateral distal preening comb with 6 spines (Fig. 26e). STC I, II with 9 long teeth, ITC with single tooth, tarsal claws I-III reduced in size, tarsal claws IV normal. Tarsi with distal ventral scopulose setae.
Pedipalp: Tibia bulbous and rounded sinuous, about 2x the length of the cymbium; cymbium rounded square, triangular apically with elongate setae; bulb rounded oblong, embolus originating medially from ventral edge of bulb, short, broad and curved from about ½ of its length, hooked apically (Fig. 27a–c).
Description. ♀ (based on QVMAG QVM:2019:13:0223). Total length 15.3.
Colour in ethanol: Carapace dark, reddish brown, darker anteriorly, cover of black setae; sternum dark redbrown, with pale brown cream longitudinal median strip anteriorly, with moderately long, scattered dark setae, labium darker brown, paler apically, maxillae red brown, paler apically, chelicerae dark red brown with dense, long, black setae; abdomen dorsally dark grey, with alternating faint dark and paler cream, not well defined chevrons, ventrally dark grey with yellow book lungs and yellow spinnerets. Legs red brown, with paler yellow longitudinal patches dorsally and on joints, covered with long dark setae (Fig. 28a–h).
Cephalothorax: 7.1 long, 3.6 wide, 3.2 high. Carapace elongated oblong, with broad, square ‘neck’ anteriorly, anterior edge convex, posteriorly with defined median indent, fovea an ill-defined shallow pit (Fig. 28a); lateral profile low flattened dome, highest point posterior to eye group (Fig. 28c). 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. 28b). Eye group 1.30 wide, 0.54 of anterior carapace width. Posterior eye row slightly recurved, eyes small, three pairs of eyes widely separated (Fig. 28d).
Abdomen: 8.2 long. Covered in fine dense setae (Fig. 28a).
Legs: Leg length ratio: II>I>IV>III. Leg I femur 5.0, patella 2.0, tibia 3.6, metatarsus 2.6, tarsus 1.1. Leg II femur 4.6, patella 2.2, tibia 4.5, metatarsus 3.7, tarsus 1.1. Leg III femur 2.5, patella 2.3, tibia 2.7, metatarsus 1.9, tarsus 0.8. Leg IV femur 3.8, patella 2.0, tibia 3.3, metatarsus 2.5, tarsus 0.8. Femur I bowed in dorsal view. Macrosetae: Leg I femur: d1, dp3ap; tibia dp1-1-1-1-1, p1-1-1, pv1-1-1ap, rv1-1-1ap, r1-1-1; metatarsus pv1-1-1-1-1-1-1ap, v1, rv1-1-1-1-1-1-1-1. Leg II d1, dp3ap; tibia p1-1-2-2, pv1ap, rv1-1-1-1-1-1ap; metatarsus pv2-1-1-1-1-1ap, v1, rv1-1-1-1-1-1-1ap. Leg IV femur d1-1-1, d1ap; tibia p1-1-1-1, pv1ap, v1; metatarsus p1, v1, rv1-1-1-1ap, v1-1ap. Retrolateral distal preening comb with 6 macrosetae (Fig. 28e). STC I, II with 6 teeth, ITC with small tooth.
Pedipalp: Pedipalp with single, toothless claw. Dense clusters of proventral macrosetae on tarsus and tibia. Dense scopulose setae on tarsus.
Genitalia: Anterior receptaculum hooked apically in ventral view, unilobed (Fig. 29a–b).
Variation. In females, the colour of A. segmentata is quite variable, ranging from dark reddish brown as illustrated by the exemplar specimen, to a much lighter cream brown, with more distinct transverse abdominal markings. In some very dark specimens, the abdominal markings are very faint; but the pale, longitudinal median mark anteriorly on the sternum was present in all species examined. There was consistency in the structure of the male pedipalps and in the number of macrosetae in the preening comb on metatarsus IV and macrosetae on tibia and metatarsus of leg I of males and females.
Remarks. The holotype of A. segmentata was examined by images provided by E. Leguin, MNHN and could not be measured and examined in detail. We here provide a redescription based on a more recently collected material that is representative of this species.
Distribution. Widespread across Tasmania (Fig. 30).
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 182-186, DOI: 10.11646/zootaxa.5105.2.1, http://zenodo.org/record/6332569