Ariadna fragilis, Marsh & Stevens & Framenau, 2022

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, Zootaxa 5105 (2), pp. 151-201 : 174-175

publication ID	https://doi.org/ 10.11646/zootaxa.5105.2.1
publication LSID	lsid:zoobank.org:pub:4F6F5BC6-2AAF-4B23-882E-F77C63BE4CC2
DOI	https://doi.org/10.5281/zenodo.6333419
persistent identifier	https://treatment.plazi.org/id/4FECFD82-2DE9-4643-A792-A8938643C7D6
taxon LSID	lsid:zoobank.org:act:4FECFD82-2DE9-4643-A792-A8938643C7D6
treatment provided by	Plazi
scientific name	Ariadna fragilis
status	sp. nov.

Treatment

Ariadna fragilis View in CoL sp. nov.

Figs 20a–h View FIGURE 20 , 21a–c View FIGURE 21 , 19 View FIGURE 19

http://zoobank.org/NomenclaturalActs/4fecfd82-2de9-4643-a792-a8938643c7d6

Type material. Holotype ♂. AUSTRALIA: Tasmania: Mount Chappell Island in Bass Strait , 40.27°S, 147.52°E, 29 July 1989 – 7 August 1989, coll. S. Fearn ( QVMAG QVM:2020:13:0111) GoogleMaps

Other material examined. Known only from the type specimen.

Etymology. The specific epithet is a Latin adjective meaning ‘fragile’ and refers to the slender form of the species.

Diagnosis. Ariadna fragilis sp. nov. is most similar to A. abbreviata sp. nov., A. clavata and A. tigrina sp. nov.. It is differentiated from A. abbreviata sp. nov. by the lack of shortened, blunt macrosetae prolaterally on metatarsus I ( Fig. 20f–h View FIGURE 20 cf. Fig. 1f–h View FIGURE 1 ). It is differentiated from A. clavata by its slenderer pedipalp tibia compared to the cymbium length and by the embolus, which is less hooked apically in A. fragilis sp. nov., than in A. clavata ( Fig. 21a, b View FIGURE 21 cf. fig. 1g, i Marsh et al. 2018). The species is differentiated from A. tigrina sp. nov. by its longer and slenderer pedipalp tibia ( Fig. 21a, b View FIGURE 21 cf. Fig. 39a, b View FIGURE 39 ), and by the pattern of macrosetae on the tibia and metatarsus of leg I, which is paired in A. fragilis sp. nov. ( Fig. 20f–h View FIGURE 20 cf. Fig. 37f–h View FIGURE 37 ).

Description. ♂ (based on holotype; QVMAG QVM:2020:13:0111). Total length 4.7.

Colour in ethanol: Carapace golden, orange brown, sparse, scattered light setae, caput area raised anterior to fovea and lighter yellow brown; sternum yellow brown, with sparse long brown setae, maxillae yellow brown, paler in colour apically, labium darker orange brown, chelicerae orange brown; abdomen dorsally pale grey, with nine dark grey, clearly defined chevrons, with triangular extensions in the centre and joined by dark median line, ventrally cream with dark patches centrally and laterally. Legs yellow brown, with darkened patches distally tibiae I and II, with sparse brown setae ( Fig. 20a–c View FIGURE 20 ).

Cephalothorax: 2.2 long, 1.4 wide. Carapace oval, blunt anteriorly, caput raised towards anterior, highest at eyes, fovea shallow ( Fig. 20a View FIGURE 20 ); in lateral view carapace projected forward over clypeus ( Fig. 20c View FIGURE 20 ). Labium narrowed anteriorly, about ¾ length of maxillae; chelicerae with basal transverse ridge, retromargin with single tooth, promargin with three teeth; sternum oval, domed with precoxal triangles and with smaller, rounded intercoxal extensions ( Fig. 20b View FIGURE 20 ). Posterior eye row straight, eye group occupying about a third of carapace width ( Fig. 20d View FIGURE 20 ).

Abdomen: 2.5 long. Covered in fine dense setae ( Fig. 20a View FIGURE 20 ).

Legs: Leg length ratio: I>II>IV>III. Leg I femur 1.2, patella 0.4, tibia 1.5, metatarsus 1.3, tarsus 0.5. Leg II femur 0.9, patella 0.4, tibia 1.4, metatarsus 1.2, tarsus 0.6. Leg III femur 1.1, patella 0.5, tibia 0.9, metatarsus 0.6, tarsus 0.4. Leg IV femur 1.3, patella 0.5, tibia 1.2, metatarsus 0.7, tarsus 0.4. Femur I bowed in dorsal view. Macrosetae: Leg I: femur dp2ap; tibia p1, pv1-1-1 (long)-1ap, rv1-1-1ap; metatarsus pv1-1-1, rv1-1-1-1ap. Leg II femur dp1ap; tibia dp1-1-2, dp1ap, v1-1-1ap; metatarsus pv1-1-1-1ap, v1, rv1-1-1-1/0ap. Leg IV tibia v1-1; metatarsus r1- 1-1ap, rv1. Retrolateral distal preening comb with 6 spines ( Fig. 20e View FIGURE 20 ). STC I, II with 11 long teeth, ITC with single long tooth, Tarsi with distal ventral scopulose setae.

Pedipalp tibia short, about 1 ½ the length of the cymbium; cymbium rounded square shape, with anterior prolateral extension; bulb pyramidal in lateral view, embolus elongate, thin and hooked apically ( Fig. 21a–c View FIGURE 21 ).

Variation. Known only from the type specimen.

Distribution. Known only from type locality, Mount Chappell Island in the Furneaux Group ( Fig. 19 View FIGURE 19 ).