Agroeca istia de Biurrun & Barrientos 2021, sp. n.
Creators: name: Biurrun, Gabriel De
name: Barrientos, José Antonio
name: Baquero, Enrique
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Liocranidae
Agroeca
Agroeca istia

description: Agroeca istia de Biurrun & Barrientos sp. n.
Figs 2–4
urn:lsid:zoobank.org:act: 8F165F62-2C37-4549-947F-901D3461B77F
Type material. Holotype Ƌ (MZNA 716538), pitfall trap in pine forest, 3.III.2014. Allotype ♀ (MZNA 716544), direct capture in pine forest, 18.III.2014.
Paratypes: 8 ♀, 11 Ƌ, 1 immature (28.X.2013 – 29.X.2014), all from Vedado de Eguaras, Bardenas Reales, Navarra, Spain (42.25°N, 01.52°W).
Etymology. The species name istia, feminine, is derived from the ancient Greek term “ ἱστία ”, for the noun ‘sail’, and it also applies to the Vela constellation. It refers here to the flat triangular keel protruding in the middle of the embolic base of the male pedipalp, resembling the triangular sail of a ship (TK in Fig. 2A).
Diagnosis. Males are distinguished by the presence of a triangular keel (TK in Figs 2 A–B, 3C) at the base of embolus, clearly seen in the ventral view, widely spaced between a prolateral bulge (PB in Figs 2 A–B, 3A, C) and the terminal plate from which the embolus emerges (EP in Figs 2A, E, 3C). The tibial apophysis (Figs 2 A–C, E) is long and thin, and it does not appear truncated in lateral view (Fig. 2E). The female can be distinguished by the profile of the copulatory ducts, showing an inverted U shape (Figs 2I, K, 3B).
Description. Description. Male (Fig. 2H): total length 4.03 (3.34–4.43); prosoma 1.78 long (1.64–1.97), 1.40 wide (1.34–1.53). Female (Fig. 2G): total length 4.72 (4.49–4.99); prosoma 2.06 long (1.64–2.16), 1.56 wide (1.36– 1.85). Leg measurements are shown in Table 1. Leg spination of holotype is depicted in Fig. 4. Colour: carapace in both sexes with yellowish median stripe, rest of carapace dark brown with faint radiating stripes. Fovea conspicuous. Abdomen reddish-brown, with vague chevron-like pattern, more evident in females. Legs yellowish.
Palp (Figs 2 A–F, 3A, C): RTA long, slightly curved in proximal half; twice as broad at base, pointed at tip (Figs 2C, E). Cymbium with apical scopula (CS in Figs 2D, F). Base of embolus consists of three differentiated parts: a prolateral bulge (PB in Figs 2 A–F, 3A, C) divided by distinct furrow, a flat triangular keel (TK in Figs 2 A–B, 3C), and a retrolateral non-forked plate from which proximal portion of embolus emerges towards cymbium (EP in Figs 2A, E, F, 3C). Embolus takes anti-clockwise turn dorsally into cymbium and, in unexpanded palp, emerges again near prolateral bulge. Membranous conductor whitish, curved and tubular (Figs 2 A–F, 3C), arises behind prolateral bulge, runs parallel to distal tip of embolus (ED in Figs 2B, E, F, 3C), ending both ventrally to triangular keel. Median apophysis with protruding retrolateral lobe, base forming semi-circular pointed hook directed towards base of tegulum.
Epigyne (Fig. 2I, 3B): often covered anteriorly by strong, dark plugs, densely covered by thick plumose hairs (Fig. 2J). Almost circular, posteriorly reaching epigastric furrow. Although barely noticeable as part of epigyne due to less pronounced sclerotization, there are two ear-shaped lateral shallow depressions (ESD in Fig. 2I) ending posteriorly on semi-circular hoods of copulatory openings (Ho and CO in Fig. 2K). Median septum shows flanks appearing flat and wing-like anteriorly (Figs 2I, K, MS in Fig. 3B). Visible first half of copulatory duct forms inverted U-shape (Fig. 2I).
Vulva (Figs 2 K–L): after long course forming inverted U-shape from copulatory openings, copulation ducts, not touching medially (Fig. 2K), run briefly dorsally, loop in semicircle, before ending in small kidney-shaped spermathecae (Fig. 2L).
Distribution. Only known from the type locality.
Habitat. Aleppo pine forest (Pinus halepensis) and immediate surroundings, within typical salt marshes of the Bardenas area.
description: Published as part of Biurrun, Gabriel De, Barrientos, José Antonio & Baquero, Enrique, 2021, A new species of Agroeca Westring, 1861 from Navarra, Spain (Araneae Liocranidae), pp. 84-90 in Zootaxa 4941 (1) on pages 86-87, DOI: 10.11646/zootaxa.4941.1.4, http://zenodo.org/record/4594746