Eustala occidentalis, sp. nov.
Creators: name: Baert, Léon
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Araneidae
Eustala
Eustala occidentalis

description: Eustala occidentalis sp. nov.
urn:lsid:zoobank.org:act:95A5F993-4A60-4567-ABAD-9D8489A5EDD3
Figs 1 A–E, 2 A–F, 5 A, 6 A, 7
Epeira prompta Hentz, 1847. – Banks 1902: 61; 1924: 97. — Snodgrass 1902: 76. — Roth & Craig 1970: 120 (misidentiFcation).
Eustala sp. – Roth & Craig 1970: 116. — Baert 2013: 176, 178
Eustala vegeta (Keyserling, 1865). – Baert, Maelfait, Hendrickx & Desender 2008: p. 47, Map 15 — Garrett, Conner & Roque-Albelo 2008: 2–4, f. 1 (misidentiFcation).
Diagnosis
Male: Terminal apophysis needle-like, short and slightly curved, its apical and caudal ridges equal in length and structure.
Etymology
The species name refers to its distribution in the western part of the archipelago.
Type material
Holotype
♂, ISLA SANTA CRUZ, Bahía Tortuga, arid zone, 14 Mar. 1986, leg. Baert, Maelfait & Desender.
Allotype
♀, ISLA SANTA CRUZ, Along the road connecting the Charles Darwin Research Station to Puerto Ayora, Arid zone, 15 Apr. 1982, leg. Baert & Maelfait.
Paratypes
ISLA SANTA CRUZ: 1 Ƌ, 1 ♀, CDRS, 1 Mar. 1986 (B.86/046); 1 Ƌ, CDRS, 2 Mar. 1986 (B.86/047); 1 ♀, 1 j ♀, CDRS, 11 Mar. 1986 (B.86/083); 1 Ƌ, CDRS, 16 Mar. 1986 (B.86/0124); 2 ƋƋ, CDRS, dormitorio, Mar. 1986 (leg. Baert, Maelfait & Desender 1986). 1 Ƌ, 2 j, CDRS, dormitorio, 17 Feb. 1988 (B.88/317) (leg. Baert, Maelfait & Desender 1988); 1 Ƌ, 3 km South of Bellavista, alt. 115 m, 1–29 Feb. 1989 (P.89/81); 1 Ƌ, CDRS, dormitorio, Apr. 1991 (B.91/757) (leg. Baert, Maelfait & Desender, 1991); 1 ♀, 2.7 km of Los Gemelos, alt. 500 m, 23 Mar. 1996 (B.96/6); 1 ♀, Media Luna, alt. 600m, 11 Mar. 1998 (B.98/015) (leg. Baert, Maelfait & Desender, 1998); 1 ♀, 1 (♀), 1 (Ƌ), 2 j (s), Cerro Colourado, alt. 10 m, 10 Mar. 1975 (leg. W.G. Reeder); 1 ♀, Horneman farm, Bellavista, alt. 225 m, cultivated zone, 14 Oct. 1975 (leg. W.G. Reeder); 1 ♀, 1 j, nesting zone 3 area, 1 Aug. 1970 (leg. Riechert); 1 ♀, northern base of Media Luna, alt. 610-620 m, open shrub savanna of Miconia surrounded by ferns and grasses, 3 May 1980 (leg. W.G. Reeder); 2 ♀♀, 1 (Ƌ), 1 (♀), 3 j (s), CDRS, Academy Bay, altitude 5–15 m, from Scutia, Croton, Castela and Cryptocarpus plants, 16 Aug. 1977 (leg. W.G. Reeder); 1 ♀, 6 j (s), CDRS, Academy Bay, alt. 10 m, from Scutia, Cryptocarpus and Scalesia plants, 18 Oct. 1975 (leg. W.G. Reeder).
RBINS inventory number of all type material is I.G. 32722.
Other material examined originating from the islands Fernandina, Isabela (Volcán Sierra Negra, Volcán Alcedo, Volcán Darwin), Marchena, Pinta and Santiago (see Table 1).
Description
Male (holotype)
LENGTH. Total length 5.80; carapace length 3.14, width 2.63, height 0.75; abdomen length 3.65, width 2.63.
CARAPACE. Colour (in alcohol) yellowish with clypeus and eye region black, dorsal cephalic part black with central yellow V; two short, diverging combs of long, thin, white hairs starting from PME and PLE. Chelicerae black with few yellow stains. Labium black with white apical edge. Endites black with white apical and inner edges. Sternum white with irregular blackish suffused border. Pedipalps with striped yellow-black appearance. Legs yellow with variable black annulations.
ABDOMEN. Dorsum white with distinct dorsal dark folium pattern (colour pattern A), with six sclerotized apodemes; venter black with central white patch; spinnerets dark.
EYES. MOQ: PME = 0.72 AME. Cl = 0.5 DAME.
LEGS. Measurements:
I (15.23): Fe 4.63, Pa 1.65, Ti 3.73, Mt 3.73, Ta 1.49
II (11.48): Fe 3.57, Pa 1.25, Ti 2.43, Mt 2.94, Ta 1.29
III (6.81): Fe 2.43, Pa 0.86, Ti 1.33, Mt 1.37, Ta 0.82
IV (10.35): Fe 3.57, Pa 1.25, Ti 2.20, Mt 2.39, Ta 0.94
SPINATION. All legs with numerous spines.
PEDIPALP (Figs 1 A–B, 5A). One very long patellar seta, slightly longer than bulbus. Cymbium with conspicious T-shaped tarsal hook, its transverse bar slightly curved and with rounded extremities. Terminal apophysis (Fig. 6 A) needle-like, slightly bent, short, apical and caudal ridges equal in shape and length; embolus short, sharp tip, slightly curved at tip, lying in excavation of small, whitish conductor.
Female (allotype)
LENGTH. Total length 10.72; carapace length 4.20, width 3.53, height 1.18; abdomen length 7.35, width 6.78.
CARAPACE. Colour: orange brown; chelicerae creamy orange; labium, endites and sternum orange brown. Legs orange brown.
ABDOMEN. Creamy white, faintly speckled with cream spots, four apodemes; grey patches extend laterally of the proximal dots; three branched, dirty-grey lines run backwards in distal half of dorsum; venter cream with central white patch; spinnerets orange brown.
EYES. MOQ: PME = 0.79 AME. Cl = 0.9 DAME.
LEGS. Measurements:
I (18.21): Fe 5.47, Pa 2.27, Ti 4.31, Mt 4.47, Ta 1.69
II (15.41): Fe 4.59, Pa 2.12, Ti 3.45, Mt 3.80, Ta 1.45
III (9.29): Fe 3.14, Pa 1.37, Ti 1.88, Mt 1.92, Ta 0.98
IV (14.28): Fe 4.98, Pa 1.96, Ti 3.06, Mt 3.18, Ta 1.10 EPIGYNE (Fig. 1 C–E). Length of scapus 0.91, diameter (lateral view) 0.19, L/D = 2.95. Spermathecae touching each other medially; scapus evenly broad (ventral view), broadest in the middle, tip slightly curved (lateral view).
Variation
The males in our samples vary in length between 4.9 and 7.4 mm, the females between 5.7 and 10.6 mm.
A great diversity in abdominal colouration, independent of island origin, can be observed (Figure 2). The abdominal colour can vary from uniform light cream (Pattern A: for example ♂ of sample B.88/317: Santa Cruz, surroundings of CDRS, 17 Feb. 1988; Allotype ♀ from Santa Cruz and ♀ from Marchena, 26/I/1977, leg. Reeder), to very dark (Pattern B: for example ♀ specimen from Santa Cruz, Media Luna, 620 m alt., 3 May 1980, leg. Reeder), with all possible variations in between. The colour may be uniform or with a faint or a very conspicuous folium (patterns on Fig. 2 A, 2 D–F), showing two sinuous lines converging backwards. Some specimens, male and females, have a black abdomen with two large white shoulder spots (pattern, Fig. 2 C: for example Ƌ specimen from sample P.92/179: Tagus cove, Volcán Darwin, 22 May 1992, but also some specimens from Santa Cruz, Volcán Sierra Negra, Pinta and Santiago), a few with a dorsal longitudinal white band (Fig. 2 D, F) and some with a white abdomen with median black folium (Fig. 2 E). Cephalothorax also variable, with or without marked black stains.
Distribution
E. occidentalis sp. nov. has a western distribution within the archipelago (Fig. 7): Fernandina (up to 600 m alt.); the Isabela volcanoes Volcán Sierra Negra (arid zone and above 900 m alt.), Volcán Alcedo (above 300 m alt.), Volcán Darwin and Beagle Crater (coastal arid zone); Marchena; Pinta (from coast to summit); Pinzon (above 300 m alt.); Rábida; Santiago (from coast to summit); Seymour Norte; South Plaza and Santa Cruz (from coast up to 600 m alt.). There is apparently no preferred vegetation zone. It also occurs along the walls of buildings (cf. CDRS buildings of the dormitorio).
description: Published as part of Baert, Léon, 2014, Three new Eustala (Araneae, Araneidae) species from the Galápagos Islands (Ecuador), pp. 1-18 in European Journal of Taxonomy 86 on pages 3-9, DOI: 10.5852/ejt.2014.86, http://zenodo.org/record/830216