Ariadna motumotirohiva Giroti & Cotoras & Lazo & Brescovit 2020, sp. nov.
Creators: name: Giroti, André Marsola
name: Cotoras, Darko D.
name: Lazo, Pedro
name: Brescovit, Antonio Domingos
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Segestriidae
Ariadna
Ariadna motumotirohiva

description: Ariadna motumotirohiva sp. nov.
urn:lsid:zoobank.org:act: BC432E25-E52D-4E0B-896D-0BDCE97BD2D4
Figs 1–3
Segestriidae sp. – Hershauer et al. 2020: 3, fig. 3b.
Diagnosis
Females of Ariadna motumotirohiva sp. nov. are similar to those of Ariadna perkinsi Simon, 1900 and Ariadna lebronneci Berland, 1933 due to the dark dorsal abdominal pattern (Fig. 2A; Giroti & Brescovit 2018: fig. 31a, e), but differ from the former by the anterior receptaculum with the dorsal lobe globous (Fig. 3; Giroti & Brescovit, 2018: fig. 31i–j), by the presence of three promarginal teeth on the chelicerae and femur IV with dorsal macrosetae, and from the latter by four promarginal teeth (see Berland 1933: 44, figs 1–2).
Etymology
The name refers to the name given by the Rapa Nui people to the type locality, 'Motu Motiro Hiva'; noun in apposition.
Type material
Holotype
CHILE • ♀; V Región de Valparaíso, Isla Sala y Gómez; 26°28′ S, 105°28′ W; Nov. 2012; P. Lazo leg.; MNHN (MNHN 8366).
Paratype
CHILE • ♀; V Región de Valparaíso; same collection data as for holotype; IBSP (IBSP 246895).
Description
Female (holotype) (measurements in mm)
Carapace orange with cephalic region reddish orange; eyes bounded by dark outlines (Fig. 2A). Chelicerae, endites and labium dark reddish orange (Fig. 2C). Sternum light orange with darker margins, and four pairs of dark marginal areas (Fig. 2B). Palps brownish orange, gradually darkening distally (Fig. 2B). Legs brownish orange with pairs I–II darker, and metatarsi and tarsi I–II reddish orange (Fig. 2 F–G). Abdomen whitish grey, with a fainted dark dorsal pattern comprising arrow-shaped marks (Fig. 2 A–B). Total length 13.36; carapace 6.4 long, 3.76 wide. Carapace oblong, cephalic region narrower than thoracic region, with short setae conspicuously delimiting it. Six indirect eyes, with the posterior ones in a slightly recurved line (Fig. 2A). Chelicerae conical, wider basally, with frontal setae (Fig. 2A, C); chelicerae with one retromarginal and three promarginal teeth. Endites spatulate, narrowed medially, rounded distally and proximally. Labium longer than wide, with a narrowed distal region. Labrum well developed, longer than the labium (Fig. 2C). Palps short and robust, with one diaxially orientated articulated claw; tarsi and tibia with prolateral setae. Legs robust, pair III directed forward (Fig. 2 A–B, F–G). Leg formula: I-IV-II-III. Leg measurements: I, femur 4.48, patella 2.2, tibia 4.4, metatarsus 3.32, tarsus 0.72, total 15.12; II, 3.88, 2.08, 4.12, 3.04, 0.64, 13.76; III, 3.28, 1.76, 2.64, 2.52, 0.8, 11.0; IV, 4.32, 2.16, 3.6, 3.2, 0.8, 14.08. Macrosetae: I, femur d0-0-0-0-0-0/1-1-2/1-0, p0-0-0-0-1-2-1/0-1-0; tibia vp1-1-0-1/0-1-1-0-1-1-0, vr1-1-1-0-1-1-0-1-1-1-0, r0-0-1-0-0-0-0-0; metatarsus vp1-1-1-1-0/1-1- 1-1-1-1-1-0/1-0/1-1, vr1-0-1-1-0-1-1-0-1-1-1-1; II, femur d0-0-1-1-1-2-0-2-0, p0-0-0-0-0-1-0-1-0; tibia p0-1-0-1/0-1/0-0-0-0-0-0, vp1-1-1-1-1/0-1-0-1/0-1-0, vr1/2-1-1-0-1-1-0-1-1/0-0/1-1-0, r0-0-0-1/0-1/0- 0-0-0-0; metatarsus vp1-1-1-0/1-1-1-1-1-1-1-1, vr1-0-1-1-0-1-0-1-1-0-1; IV, femur d0-1-1-1-0-1/0-1/0- 0-0-0, r0-0-0-0-0-0-0-1-0-0; metatarsus vr metatarsal comb with 3 macrosetae. Abdomen membranous, longer than wide, uniformly hairy; epigastric genital plate sclerotized; tracheal system dysderoid like, with the tracheal openings positioned near the epigastric furrow (Fig. 2 A–B, D). Six spinnerets, ALS with three segments, the basal one crossed by a diagonal membranous band; PLS with distal external sclerite equally sclerotized; colulus distinct and pilose (Fig. 2E). Internal female genitalia with anterior receptaculum billobulated, dorsal lobe conspicuously longer than the ventral one, with median and ventral projections; glandular ducts plate medianly positioned; interpulmonary fold with the dorsal margin sclerotized, and a median membranous crack; posterior receptaculum membranous, with tubular invaginations (Fig. 3).
Variation
Female (n = 2): total length 10.8–13.36; carapace 5.92–6.4 long, 3.44–3.76 wide; femur I 3.76–4.48.
Note
For comparison we used the female specimen of A. perkinsi described by Giroti & Brescovit (2018) (IBSP 209056) and the original description and illustrations provided by Berland (1933: 44) of A. lebronneci.
Distribution
Only known from the type locality (Fig. 1).
description: Published as part of Giroti, André Marsola, Cotoras, Darko D., Lazo, Pedro & Brescovit, Antonio Domingos, 2020, First endemic arachnid from Isla Sala y Gómez (Motu Motiro Hiva), Chile: a new species of tube-dwelling spider (Araneae: Segestriidae), pp. 97-105 in European Journal of Taxonomy 722 on pages 99-102, DOI: 10.5852/ejt.2020.722.1137, http://zenodo.org/record/4240918