Eustala occidentalis, Baert, Léon, 2014

Baert, Léon, 2014, Three new Eustala (Araneae, Araneidae) species from the Galápagos Islands (Ecuador), European Journal of Taxonomy 86, pp. 1-18 : 3-9

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

Ƌ, 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 Ƌ 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).

Figures

Fig. 1. Eustala occidentalis sp. nov. A. Ƌ left palp, ventral view. B. Ƌ left palp, apical view. C. ♀ scapus, lateral view. D. ♀ epigyne scapus, ventral view. E. ♀, spermathecae. c = conductor, e = embolus, ma = median apophysis, sc = scapus, sp = spermathecae, sta = subterminal apophysis, ta: terminal apophysis, th = tarsal hook. Scale lines = 0.5 mm.

Fig. 2. Eustala occidentalis sp. nov., examples of abdominal patterns. A. ♀ from Isla Rábida. B. ♀ from Isla Santa Cruz. C. Ƌ from Isla Isabela, Tagus Cove. D. ♀ from Isla Pinta. E. Ƌ from Isla Santa Cruz. F. ♀ from Isla Santiago. Scale lines = 1 mm. Photographs: Alain Pauly.

Fig. 6. Electron microscopic photographs of terminal apophysis of Ƌ left palp. A. Eustala occidentalis sp. nov. B. Eustala meridionalis sp. nov. C. Eustala orientalis sp. nov. Scale lines = 0.1 mm.

Fig. 7. Distribution map of Eustala occidentalis sp. nov., Eustala occidentalis sp. nov. and Eustala meridionalis sp. nov.

Tables

Table 1. Other material examined of Eustala occidentalis sp. nov. Abbreviations: BAL: Baltra, EDE: Eden, FER: Fernandina, IBC: Isabela, Beagle Crater, ISN: Isabela, Sierra Negra, IVA: Isabela, Volcán Alcedo, IVD: Isabela, Volcán Darwin, MAR: Marchena, PIN: Pinta, PIZ: Pinzón, RAB: Rábida, SAN: Santiago, SEY: Seymour Norte, SPL: South Plaza; Ƌ: male, (Ƌ): subadult male,♀: female, (♀): subadult female, j(s): juvenile(s), #: several.

Island	Locality	Altitude	Date	Sex	Lit. / Leg.
BAL					Roth & Craig, 1970
EDE				j	99/LR
FER	500 m S of Cabo Hammond	10 m	1 May 1975	1♀	75/ WGR
FER	West vegetation strip, camp area	20 m	10 Aug. 1977	1♀ 1(Ƌ) 7j (s)	77/ WGR
FER	Between Cabo Hammond & Bursera Hills	70 m	26 Apr. 1975	3 ƋƋ 2 (Ƌ) 1♀ 1(♀) 10j (s)	75/ WGR
FER	Cerro Verde	170 m	9 May 1991	2ƋƋ 2♀♀ 2j (s)	91/ LB,JPM,KD
FER	W slope, 500m S of camp crater	380 m	16 Aug. 1977	1♀	77/ WGR
FER	W slope of camp crater	450 m	16 Aug. 1977	3 ƋƋ 4♀♀ 2(Ƌ) 4(♀♀) #j(s)	77/ WGR
FER	Along encañada	600 m	7 May 1991	1j ♀	91/ LB,JPM,KD
IBC	Camp		22 May 1980	7Ƌ 3(Ƌ) 13♀♀ 3(♀) #j(s)	80/ WGR
IBC	Outside crater wall	40-50 m	22 May 1980	1Ƌ 2j (s)	80/ WGR
ISN	Lagoons of Villamil		14 Jul. 1970	1♀	70/ SR
ISN	Near Villamil (road to highlands, 1 km from sea)	10-15 m	11 Jul. 1978	2ƋƋ 2♀♀	78/ WGR
ISN	Camp above Alemania	540 m	24 Jan. 1975	5ƋƋ 1(Ƌ) 8♀♀ 1(♀) #j(s)	75/ WGR
ISN	Camp above Alemania	540 m	23 Jan. 1978	1Ƌ 5♀♀	78/ WGR
ISN	Crater rim	925 m	19 Feb. 1986	1Ƌ	86/ LB,JPM,KD
IVA	E slope	340 m	18 May 1980	1Ƌ	80/ WGR
IVA	West of lava Fow (W slope)	370-380 m	25 May 1980	2ƋƋ 8♀♀ #j(s)	80/ WGR
IVA	Pega Pega camp	380 m	23 May 1980	1Ƌ 2(Ƌ) 4(♀) 6j (s)	80/ WGR
IVA	E slope	380 m	25 May 1980	1Ƌ	80/ WGR
IVA	W slope	620-1260 m	21–23 May 1980 1♀♀		80/ WGR
IVA	Pega Pega camp	780 m	13 May 1980	1Ƌ 7♀♀ #j(s)	80/ WGR
IVA	West of lava Fow (W slope)		23 May 1980	1♀ 1(♀) 2j (s)	80/ WGR
IVA	East of lava Fow		24 May 1980	1♀ 6j (s)	80/ WGR
IVA	East rim	1045 m	16 May 1980	1♀	80/ WGR
IVA	East rim	1045 m	17 May 1980	1Ƌ 7♀♀ #j(s)	80/ WGR
IVD	Tagus Cove	20 m	13–22 May 1992 1Ƌ		92/ SP
IVD	Flat between IBC & IVD	40-50 m	22 May 1980	3ƋƋ 4(Ƌ) 11♀♀ 6(♀) #j(s)	80/ WGR
MAR	Playa Negra		10 Mar. 1988	#j(s)	88/ LB,JPM,KD
MAR	Punto Mejio		11 Mar. 1988	1j ♀	88/ LB,JPM,KD
MAR	Playa Negra		29 Mar. 2000	2ƋƋ 1♀	00/ LB,JPM,KD
MAR	SW slope of beach camp area	5 m	24 Jan. 1977	1Ƌ 4♀♀ 3(♀) 7j (s)	77/ WGR
MAR	Above beach at Beach camp (S slope)	5-10 m	26 Jan. 1977	2ƋƋ 2(Ƌ) 9♀♀ 3(♀) 12j (s)	77/ WGR
MAR	S Playa camp, new lava Fow	16-20 m	31 Jan. 1977	1Ƌ 1(Ƌ) 2j (s)	77/ WGR
MAR	SW Playa, Bursera forest	30 m	12–24 Mar. 1992 1Ƌ		92/ SP
MAR		50 m	10 Mar. 1988	1j ♀	88/ LB,JPM,KD
MAR	Fumarole at Barranco	160-190 m	29 Jan. 1977	2ƋƋ 2♀♀ 3(♀) 5j (s)	77/ WGR
PIN	Cabo Ibbetson		31 Mar. 2000	1Ƌ	00/ LB,JPM,KD