http://dx.doi.org/10.5852/ejt.2014.86

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Research article

um:lsid:zoobank.org:pub:E0120985-24A8-4280-B10A-68982C7DD762

Three new Eustala (Araneae, Araneidae) species from the

Galapagos Islands (Ecuador)

Leon BAERT

O.D. Taxonomy and Phytogeny, Royal Belgian Institute of Natural Seienees, Vautierstraat 29,

B-1000, Brussels, Belgium.

E-mail: [email protected]

um:lsid:zoobank.org:author:05FB6C55-2E74-4AF2-86A5-83B738C6BA66

Abstract. Three new Eustala speeies are deseribed from the Galapagos arehipelago: Eustala occidentalis

sp. nov. with a western distribution, Eustala orientalis sp. nov. with an eastern distribution and Eustala

meridionalis sp. nov. with a distribution restrieted to the southern island Floreana.

Key words, new speeies, eolour variation, island fauna

Baert L. 2014. Three now Eustala (Araneae, Araneidae) species from the Galapagos Islands (Ecuador). European

Journal of Taxonomy 86: 1-18. http://dx.doi.org/10.5852/eit.2014.86

Introduction

Because they construct conspicuous orbwebs, Araneidae are among the most prominent group of

spiders. With 169 genera and more than 3000 described species, it is also one of the largest spider

families (Jocque et al. 2013; Platnick 2014). On the Galapagos Islands, the family is represented by nine

genera: Cyclosa Menge, 1866, Galaporella Fevi, 2009, Gasteracantha Sundevall, 1833, Mastophora

Holmberg, 1876, Metazygia F.O.Pickard-Cambridge, 1904, Metepeira F.O.Pickard-Cambridge, 1903

and Neoscona Simon, 1864 are represented by one species each, and Argiope Audouin, 1826 by two

species (Baert et al. 2008; Baert 2013). In this paper, I report on the ninth genus, Eustala Simon, 1895,

which is the most speciose araneid genus of the archipelago with three species, here described as new.

The American continent harbours 82 species of the genus Eustala, of which half are found in South

America. Most of these (35 species) occur in the eastern and southern part (Guyana, Brazil, Uruguay

and Argentina) of the South American mainland. Only six species are cited from the western part, more

precisely from Peru, but none from Ecuador (Platnick 2014).

The Eustala specimens found on the Galapagos have so far been assigned to one species: Eustala vegeta

(Keyserling, 1865) (Baert et al. 2008; Garrett et al. 2008). However, a more detailed analysis of the

male palp and the female scapus shows that they belong to a complex of three different species, each

with a well defined, segregated distribution over the islands of the archipelago. The males can easily

be distinguished by the structure of their terminal apophyses, the females by the shape of their scapus.

European Journal of Taxonomy 86: 1-18 (2014)

Material and methods

The material studied eonsists of samples taken by the following sampling teams (field numbers

in braekets): L. Baert & J.-P. Maelfait (82/LB,JPM), L. Baert, J.-P. Maelfait & K. Desender (86/

LB,JPM,KD; 88/LB,JPM,KD; 91/LB,JPM,KD; 00/LB,JPM,KD), J. Herathy (91/JH), S. Peek (89/SP;

92/SP; 96/SP), W.G. Reeder (75/WGR; 77/WGR; 78/WGR; 79/WGR; 80/WGR), S. Rieehert (70/SR)

and L. Roque (99/LR).

The type material of the three speeies is deposited in the eolleetions of the Royal Belgian Institute of

Natural Seienees, Brussels (Belgium).

Speeimens were examined and measured with a Wild M5 stereo-mieroseope, and illustrated using a Wild

MIO stereomieroseope. The eleetron mieroseope photographs were made with an ESEM FEl QUANTA

200 mieroseope. The eolour photographs were made with a Nikon D7000 with an AF Miero Nikkor 60

mm objeetive. All measurements are in mm.

The left male palps are depleted, exeept the right one for E. orientalis. The female genitalia were eleared

in a methylsalieylate solution.

Abbreviations

AME

CDRS

DAME

j(s)

E/D

MOQ

PEE

PME

(c?)

(?)

Anterior Median Eyes

Clypeus length

Charles Darwin Researeh Station

Diameter of Anterior Median Eye

Femur

juvenile(s)

length of seapus/diameter of seapus

Median Oeular Quadrat

Metatarsus

Patella

Posterior Eateral Eye

Posterior Median Eye

Subadult

Tarsus

Tibia

subadult male

subadult female

Results

Taxonomy

Class Araehnida Cuvier, 1812

Order Araneae Clerek, 1757

Family Araneidae Clerek, 1757

Genus Eustala Simon, 1895

Diagnosis of the genus

The earapaee has a deep longitudinal eleft in the thoraeie region. The abdomen has a triangular shape

with a dorsal folium pattern and a ventral white pateh. The posterior median eyes are usually slightly

smaller than the anterior median eyes. The males are smaller than the females. The distal margin of the

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

male first eoxa has a distinet hook, whieh fits into a groove on the seeond femur. The palpal patella has

one very long maeroseta. The bulb has a huge, variably-shaped eonduetor and a eonspieuous white,

eone-shaped median apophysis produeed downward on the ventral side of the large bulb. Females are

eharaeterized by the seapus of the epigyne projeeting forward.

The males of the three speeies deseribed here differ from all known Eustala speeies by the strueture

of the terminal apophysis, the subterminal apophysis and the embolus, the females by the shape of the

anteriorly projeeting seapus.

The males of these three Galapagos speeies differ from eaeh other by the strueture of their terminal

apophysis (Fig. 6) while the females are reeognized by the shape of their seapus (Figs 1C, 3C, 4C).

Eustala occidentalis sp. nov.

um:lsid:zoobank.org:aet: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 (misidentifieation).

Eustala sp. - Roth & Craig 1970: 116. —Baert 2013: 176, 178

Eustala vegeta (Keyserling, 1865). - Baert, Maelfait, Hendriekx & Desender 2008: p. 47, Map 15 —

Garrett, Conner & Roque-Albelo 2008: 2-A, f 1 (misidentifieation).

Diagnosis

Male: Terminal apophysis needle-like, short and slightly eurved, its apieal and eaudal ridges equal in

length and strueture.

Etymology

The speeies name refers to its distribution in the western part of the arehipelago.

Type material

Holotype

(?, ISFA SANTA CRUZ, Bahia Tortuga, arid zone, 14 Mar. 1986, leg. Baert, Maelfait & Desender.

Allotype

$, ISFA SANTA CRUZ, Along the road eonneeting the Charles Darwin Researeh Station to Puerto

Ay ora. Arid zone, 15 Apr. 1982, leg. Baert & Maelfait.

Paratypes

ISFA SANTA CRUZ: I 3,1 ?, CDRS, I Mar. 1986 (B.86/046); I 3, CDRS, 2 Mar. 1986 (B.86/047);

I ?, I j ?, CDRS, II Mar. 1986 (B.86/083); I 3 , CDRS, 16 Mar. 1986 (B.86/0I24); 2 33 , CDRS,

dormitorio. Mar. 1986 (leg. Baert, Maelfait & Desender 1986). 1 3,2 j, CDRS, dormitorio, 17 Feb. 1988

(B.88/317) (leg. Baert, Maelfait & Desender 1988); I 3,2 km South ofBellavista, alt. 115 m, 1-29 Feb.

1989 (P.89/81); 1 3 , CDRS, dormitorio, Apr. 1991 (B.91/757) (leg. Baert, Maelfait & Desender, 1991); 1

$, 2.7 km ofFos Gemelos, alt. 500 m, 23 Mar. 1996 (B.96/6); 1 $, MediaFuna, alt. 600m, 11 Mar. 1998

(B.98/015) (leg. Baert, Maelfait & Desender, 1998); 1 1 (?), 1 ( 3 ), 2 j(s), Cerro Colourado, alt. 10 m,

10 Mar. 1975 (leg. W.G. Reeder); 1 Homeman farm, Bellavista, alt. 225 m, eultivated zone, 14 Get.

1975 (leg. W.G. Reeder); 1 5, 1 j, nesting zone 3 area, 1 Aug. 1970 (leg. Rieehert); 1 $, northern base

of Media Funa, alt. 610-620 m, open shrub savanna of Miconia surrounded by ferns and grasses, 3 May

1980 (leg. W.G. Reeder); 2 $ 1 { 3 ), 1 (?), 3 j(s), CDRS, Aeademy Bay, altitude 5-15 m, from Scutia,

Croton, Castela md Cryptocarpus 16 Aug. 1977 (leg. W.G. Reeder); 1 6j(s), CDRS, Aeademy

Bay, alt. 10 m, from Scutia, Cryptocarpus md Scalesia plants, 18 Get. 1975 (leg. W.G. Reeder).

European Journal of Taxonomy 86: 1-18 (2014)

Fig. 1. Eustala occidentalis sp. nov. A. S left palp, ventral view. B. S left palp, apieal view. C. $ seapus,

lateral view. D. 5 epigyne seapus, ventral view. E. 5 , spermatheeae. e = eonduetor, e = embolus, ma =

median apophysis, se = seapus, sp = spermatheeae, sta = subterminal apophysis, ta : terminal apophysis,

th = tarsal hook. Seale lines = 0.5 mm.

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

RBINS inventory number of all type material is LG. 32722.

Other material examined originating from the islands Femandina, Isabela (Volean Sierra Negra, Volean

Aleedo, Volean Darwin), Marehena, Pinta and Santiago (see Table 1).

Description

Male (holotype)

LENGTH. Total length 5.80; earapaee length 3.14, width 2.63, height 0.75; abdomen length 3.65, width 2.63.

Carapace. Colour (in aleohol) yellowish with elypeus and eye region blaek, dorsal eephalie part blaek

with eentral yellow V; two short, diverging eombs of long, thin, white hairs starting from PME and PEE.

Chelieerae blaek with few yellow stains. Eabium blaek with white apieal edge. Endites blaek with white

apieal and inner edges. Sternum white with irregular blaekish suffused border. Pedipalps with striped

yellow-blaek appearanee. Eegs yellow with variable blaek annulations.

Abdomen. Dorsum white with distinet dorsal dark folium pattern (eolour pattern A), with six selerotized

apodemes; venter blaek with eentral white pateh; spinnerets dark.

Eyes. MOQ: PME = 0.72 AME. Cl = 0.5 DAME.

Eegs. 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.

Pedipaep (Figs lA-B, 5A). One very long patellar seta, slightly longer than bulbus. Cymbium with

eonspieious T-shaped tarsal hook, its transverse bar slightly eurved and with rounded extremities.

Terminal apophysis (Fig. 6 A) needle-like, slightly bent, short, apieal and eaudal ridges equal in shape and

length; embolus short, sharp tip, slightly eurved at tip, lying in exeavation of small, whitish eonduetor.

Female (allotype)

EENGTH. Total length 10.72; earapaee length 4.20, width 3.53, height 1.18; abdomen length 7.35, width

6.78.

Carapace. Colour: orange brown; ehelieerae ereamy orange; labium, endites and sternum orange brown.

Legs orange brown.

Abdomen. Creamy white, faintly speekled with eream spots, four apodemes; grey patehes extend

laterally of the proximal dots; three branehed, dirty-grey lines run baekwards in distal half of dorsum;

venter eream with eentral white pateh; 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 Q4.28): Fe 4.98, Pa 1.96, Ti 3.06, Mt 3.18, Ta 1.10

European Journal of Taxonomy 86: 1-18 (2014)

Table 1. Other material examined of Eustala occidentalis sp. nov. Abbreviations: BAL: Baltra, EDE:

Eden, FER: Femandina, IBC: Isabela, Beagle Crater, ISN: Isabela, Sierra Negra, IVA: Isabela, Volean

Aleedo, IVD: Isabela, Volean Darwin, MAR: Marehena, PIN: Pinta, PIZ: Pinzon, RAB: Rabida, SAN:

Santiago, SEY: Seymour Norte, SPE: South Plaza; S\ male, ((5): subadult male, $: female, ($): subadult

female, j(s): juvenile(s), #: several.

Island

Locality

Altitude

Date

Sex

Lit. / Leg.

BAL

Roth & Craig, 1970

EDE

99/ER

FER

500 m S of Cabo Hammond

10 m

1 May 1975

75AVGR

FER

West vegetation strip, camp area

20 m

10 Aug. 1977

1? l((?)7j(s)

77AVGR

FER

Between Cabo Hammond & Biirsera Hills

70 m

26 Apr. 1975

3(^(^2((^)1? l(?)10j(s)

75AVGR

FER

Cerro Verde

170 m

9 May 1991

2(^c^2??2j(s)

91/EB,JPM,KD

FER

W slope, 500m S of camp crater

380 m

16 Aug. 1977

77AVGR

FER

W slope of camp crater

450 m

16 Aug. 1977

3(?6'4?¥2((?)4(?¥)#j(s)

77/WGR

FER

Along encanada

600 m

7 May 1991

Ij?

91/EB,JPM,KD

IBC

Camp

22 May 1980

7^ 3(^)13?9

80/WGR

IBC

Outside crater wall

40-50 m

22 May 1980

l(^2j(s)

80AVGR

ISN

Eagoons of Villamil

14 Jul. 1970

70/SR

ISN

Near Villamil (road to highlands, 1 km from sea)

10-15 m

11 Jul. 1978

26'6'2??

78AVGR

ISN

Camp above Alemania

540 m

24 Jan. 1975

5(^(^1((^)8?? l(?)#j(s)

75AVGR

ISN

Camp above Alemania

540 m

23 Jan. 1978

78/WGR

ISN

Crater rim

925 m

19 Feb. 1986

1(^

86/EB,JPM,KD

IVA

E slope

340 m

18 May 1980

Ic?

80/WGR

IVA

West of lava flow (W slope)

370-380 m

25 May 1980

233 8??#j(s)

80/WGR

IVA

Pega Pega camp

380 m

23 May 1980

l(?2(<?)4(?)6j(s)

80AVGR

IVA

E slope

380 m

25 May 1980

80AVGR

IVA

W slope

620-1260 m

21-23 May 1980

1??

80AVGR

IVA

Pega Pega camp

780 m

13 May 1980

80AVGR

IVA

West of lava flow (W slope)

23 May 1980

1? l(?)2j(s)

80/WGR

IVA

East of lava flow

24 May 1980

l?6j(s)

80/WGR

IVA

East rim

1045 m

16 May 1980

80/WGR

IVA

East rim

1045 m

17 May 1980

l(5'7$9#j(s)

80/WGR

IVD

Tagus Cove

20 m

13-22 May 1992

1(^

92/SP

IVD

Flat between IBC & IVD

40-50 m

22 May 1980

3<?(?4((?)ll?¥6(¥)#j(s)

80AVGR

MAR

Playa Negra

10 Mar. 1988

#j(s)

88/EB,JPM,KD

MAR

Punto Mejio

11 Mar. 1988

Ij?

88/EB,JPM,KD

MAR

Playa Negra

29 Mar. 2000

2c5'c5'l?

00/EB,JPM,KD

MAR

SW slope of beach camp area

5 m

24 Jan. 1977

l(?4$?3(9)7j(s)

77/WGR

MAR

Above beach at Beach camp (S slope)

5-10 m

26 Jan. 1977

2((^)9??3(?)12j(s)

77/WGR

MAR

S Playa camp, new lava flow

16-20 m

31 Jan. 1977

l(^l((^)2j(s)

77AVGR

MAR

SW Playa, Bursera forest

30 m

12-24 Mar. 1992

1(^

92/SP

MAR

50 m

10 Mar. 1988

Ij?

88/EB,JPM,KD

MAR

Fumarole at Barranco

160-190 m

29 Jan. 1977

26'(?2??3(¥)5j(s)

77AVGR

Cabo Ibbetson

31 Mar. 2000

1(^

00/EB,JPM,KD

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

Island

Locality

Altitude

Date

Sex

Leg.

S slope, camp area

250 m

19 Jul. 1975

Im 3$$ l(m) #j(s)

75AVGR

S slope, camp area

250 m

20 Jan. 1977

77AVGR

E slope

300 m

20 Mar. 1986

86/LB,JPM,KD

W slope

300 m

21 Mar. 1986

1(^

86/LB,JPM,KD

E slope

360 m

19 Mar. 1986

86/LB,JPM,KD

W slope

400 m

30 Mar. 2000

00/LB,JPM,KD

Below summit

630 m

22 Jul. 1977

77AVGR

PIZ

Old crater camp

300-320 m

5 Feb. 1979

2<<?)#j<s)

79AVGR

PIZ

Crater camp ridge summit

320 m

6 Feb. 1979

1?(1?)#J(S)

79AVGR

RAB

Margins of lagoon

3-10 m

28 Sep. 1975

1(? 3j(s) ?

75AVGR

SAN

7 km SE of Playa Espumila

9 Jun. 1991

Ij?

91/JH

SAN

Bahia Bucanero (behind beach)

14 Apr. 1975

1? 5j(s)

75/WGR

SAN

Bahia Bucanero

3 m

18 Sep. 1975

2?? 1(?)

75/WGR

SAN

Bahia Bucanero

5-10 m

10 Sep. 1975

75/WGR

SAN

Bahia Bucanero

10-15 m

12 Sep. 1975

75AVGR

SAN

Bahia Bucanero

15 m

17 Apr. 1975

Ij? 2j(s)

75AVGR

SAN

Mina de sal

50 m

8 Mar. 1986

86/LB,JPM,KD

SAN

Transect from Bahia Bucanero to summit

75m

11 Sep. 1975

75AVGR

SAN

Cerro Cowan

260 m

7 Apr. 1982

82/LB,JPM

SAN

N slope

400 m

4 Mar. 1986

1(?)

86/LB,JPM,KD

SAN

SW slope

400 m

7 Mar. 1986

86/LB,JPM,KD

SAN

SW facing slope of crater area

810-830 m

1 Sep. 1975

6(<?)1? 16($)2j(s)??

75/WGR

SAN

1.5 km S of summit (tree fern valley)

875 m

21 Sep. 1975

4j(s)

75AVGR

SEY

10 m

26 Oct 1975

75AVGR

SPL

10-15 m

19 Mar. 1975

3(^(^l?2j(s)

75AVGR

Epigyne (Fig. IC-E). Eength of seapus 0.91, diameter (lateral view) 0.19, E/D = 2.95. Spermatheeae

touehing eaeh other medially; seapus evenly broad (ventral view), broadest in the middle, tip slightly

eurved (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 eolouration, independent of island origin, ean be observed (Figure 2). The

abdominal eolour ean vary from uniform light eream (Pattern A: for example S of sample B.88/317:

Santa Cruz, surroundings of CDRS, 17 Feb. 1988; Allotype $ from Santa Cruz and $ from Marehena,

26/1/1977, leg. Reeder), to very dark (Pattern B: for example $ speeimen from Santa Cruz, Media

Euna, 620 m alt., 3 May 1980, leg. Reeder), with all possible variations in between. The eolour may be

uniform or with a faint or a very eonspieuous folium (patterns on Fig. 2A, 2D-F), showing two sinuous

lines eonverging baekwards. Some speeimens, male and females, have a blaek abdomen with two large

white shoulder spots (pattern. Fig. 2C: for example S speeimen from sample P.92/179: Tagus eove,

Volean Darwin, 22 May 1992, but also some speeimens from Santa Cruz, Volean Sierra Negra, Pinta

and Santiago), a few with a dorsal longitudinal white band (Fig. 2D, F) and some with a white abdomen

with median blaek folium (Fig. 2E). Cephalothorax also variable, with or without marked blaek stains.

European Journal of Taxonomy 86: 1-18 (2014)

Fig. 2. Eustala occidentalis sp. nov., examples of abdominal patterns. A. $ from IslaRabida. B. $ from

Isla Santa Cruz. C. S from Isla Isabela, Tagus Cove. D. $ from Isla Pinta. E. S from Isla Santa Cruz. F.

$ from Isla Santiago. Seale lines = 1 mm. Photographs: Alain Pauly.

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

Distribution

E. occidentalis sp. nov. has a western distribution within the arehipelago (Fig. 7): Femandina (up to

600 m alt.); the Isabela voleanoes Volean Sierra Negra (arid zone and above 900 m alt.), Volean Aleedo

(above 300 m alt.), Volean Darwin and Beagle Crater (eoastal arid zone); Marehena; Pinta (from eoast

to summit); Pinzon (above 300 m alt.); Rabida; Santiago (from eoast to summit); Seymour Norte; South

Plaza and Santa Cruz (from eoast up to 600 m alt.). There is apparently no preferred vegetation zone. It

also oeeurs along the walls of buildings (ef CDRS buildings of the dormitorio).

Eustala orientalis sp. nov.

um:lsid:zoobank.org:aet:AF420B6B-A770-4731-908B-4ECF219861A9

Figs 3 A-E, 5 C, 6 C, 7

Eustala vegeta (Keyserling, 1865). - Baert, Maelfait, Hendriekx & Desender 2008: 47, map 15

(misidentifieation).

Fi/Va/fl sp.-Baert 2013: 176, 178.

Diagnosis

Males differ from E. occidentalis sp. nov. by the strueture of the terminal apophysis: flat and broadening

towards the tip, its eaudal ridge being longer than the apieal ridge. Females differ from E. occidentalis

sp. nov. by the shape of the seapus.

Etymology

The speeies name refers to its distribution in the eastern part of the arehipelago.

Type material

Holotype

S, ISFAESPANOFA, 1 km W of Punta Cevalos beaeh, vegetation of beaeh berm: Valessia, Grabowskia,

Prosopis, Cordia, 1 Feb. 1977, leg. W.G. Reeder.

Allotype

$, ISFAESPANOFA, I km W of Punta Cevalos beaeh, vegetation of beaeh berm: Valessia, Grabowskia,

Prosopis, Cordia, 1 Feb. 1977, leg. W.G. Reeder.

Paratypes

ISFAESPANOFA: I S, Bahia Gardner, Playablanea, 27 Apr. 1991 (B.91/0742) (leg. Baert, Maelfait

& Desender, 1991); 1 $, 2 ($$), Caleta at Bahia Manzanilla, 21 Mar. 2009 (B.09/014-15); 2 SS, 6

$ 3 ((?(?), k j(s), 1 km W of Punta Cevalos beaeh, vegetation of upper beaeh: Valessia, Grabowskia,

Prosopis, Cordia, 1 Feb. 1977 (leg. W.G. Reeder); 1 S, Punta Suarez, albatros eolony, 28 Feb. 1977

(leg. W.G. Reeder).

ISFOTE GARDNER near ESPANOFA: 2 $ alt. 10-30 m, through Bur sera, Croton, Alternanthera,

and ferns, 12 Feb. 1977 (leg. W.G. Reeder); 1 5, alt. 30 m, from Croton in Bursera-Opuntia-Cordia-

Croton eommunity, 12 Feb. 1977 (leg. W.G. Reeder).

RBINS inventory number of all type material is I.G. 32724.

Other material examined from the islands of Genovesa, San Cristobal and Santa Fe (see Table 2).

European Journal of Taxonomy 86: 1-18 (2014)

Table 2. Other material examined of Eustala orientalis sp. nov. Abbreviations: GEN: Genovesa, SCB:

San Cristobal, SEE: Santa Fe; S\ male, ( 6 '): subadult male,$: female, ($): subadult female, j(s):

juvenile(s).

Island

Locality

Altitude

Date

Sex

Leg.

GEN

500 m W of Playa Bahia Darwin

10-15m

23 Oct. 1975

l(^)4($)4j(s)

75AVGR

GEN

500 m SE of crater rim

50 m

25 Oct. 1975

Ij?

75AVGR

GEN

Lago Arcturus

60 m

13 Mar. 1988

1(^

88/LB,JPM,KD

SCB

Wreck Bay area, upper beach vegetation

5 m

9 Feb. 1975

16'1?

75AVGR

SCB

Cerro Mundo

550 m

13-23 Feb. 1989

89/SP

SCB

El Junco (near Cabo Guido Rosillo)

600 m

18 Feb. 1978

3<?l?2j(s)

78AVGR

SEE

Camp area

5-10 m

24 Jan. 1979

79AVGR

SFE

50-100

1-2 Apr. 1982

82/LB,JPM

SFE

1 km SSW of camp beach, second arranco

100 m

24 Jan. 1979

79AVGR

Description

Male (holotype)

LENGTH. Total length 5.06; earapaee length 2.67, width 2.16, height 0.90; abdomen length 3.41, width

2.27, height 1.96.

Carapace. Colour (in aleohol) yellow brown with elypeus and eye region blaek, dorsal eephalie part

yellow brown with eentral, faintly suffused, blaekish V; two short eombs of long white hairs diverge

from between PME and PEE. Chelieerae yellow with eentral, faintly suffused, blaekish stain. Eabium

and endites pale yellow with white margin. Sternum yellow with faintly suffused, blaekish stains in

front of eoxae. Pedipalps yellow-brown with some blaek stain. Eegs pale yellow with blaek annulations,

variable between speeimens; eoxae and proximal part of femora whitish.

Abdomen. Dorsum ereamy white with small, blaek median triangle in front, two small, white eentral

stains and distinet dark sepia folium with dark brown margins and ten brown apodemes arranged as

4-2-2-2, beeoming smaller eaudally and towards the sides; venter whitish, slightly suffused with blaek;

eolulus and spinnerets dark.

Eyes. MOQ: PME = 0.8 AME. Cl = 0.5 DAME.

Eegs. Measurements:

I (13.09): Fe 4.12, Pa 1.37, Ti 3.25, Mt 3.10, Ta 1.25

II (9.97): Fe3.06, Pa 1.14, Ti 2.12, Mt 2.55, Ta 1.10

III (5.89): Fe 2.12, Pa 0.78, Ti 1.14, Mt 1.14, Ta 0.71

IV (8.94): Fe 3.10, Pa 1.10, Ti 1.88, Mt 2.04, Ta 0.82

Spination. All legs with numerous spines.

Pedipaep (Figs 3A-B, 5C). One very long patellar seta, slightly longer than bulbus. Cymbium with

eonspieuous, rounded, T-shaped tarsal hook. Terminal apophysis (Fig. 6C) short, eaudal ridge being

longer than apieal ridge, flat and broadening towards tip.

Female (allotype)

EENGTH. Total length 7.10; earapaee length 3.10, width 2.67, height 1.06; abdomen length 4.47, width

4.16, height 3.14.

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

Fig. 3. Eustala orientalis sp. nov. A. S left palp, ventral view. B. S left palp, apieal view. C. $ seapus,

lateral view. D. $ epigyne seapus, ventral view. E. $, spermatheeae. Seale lines = 0.5 mm.

European Journal of Taxonomy 86 : 1-18 ( 2014 )

Carapace. As in male, but with more pronouneed orange tinge.

Abdomen. As in male, but more uniform grey; shoulders white; venter sepia with white stains; spinnerets

orange brown.

Eyes. MOQ: PME = 0.88 AME. Cl = 0.77 DAME.

Eegs. Measurements:

I (13.26): Fe 4.12, Pa 1.57, Ti 3.18, Mt 3.06, Ta 1.33

II (11.18): Fe 3.25, Pa 1.45, Ti 2.55, Mt 2.20, Ta 1.73

III (6.81): Fe 2.31, Pa 1.02, Ti 1.29, Mt 1.33, Ta 0.86

IV (10.32): Fe 5.57, Pa 1.37, Ti 2.16, Mt 2.24, Ta 1.98

Epigyne (Fig. 3C-E). Fength of seapus 0.47, diameter (lateral view) 0.16, F/D = 4.8. Spermatheeae

separated; seapus broader at tip (in ventral view), straight, evenly broad (in lateral view).

Variation

The males in our samples vary in length between 4.6 and 6.9 mm, the females between 5.1 and 8 mm.

The eolour variation of the abdomen is eomparable to that of the previous speeies.

Distribution

E. orientalis sp. nov. has an eastern distribution within the arehipelago (Fig. 7): Espanola (arid zone),

Islote Gardner near Espanola, Genovesa (arid zone), San Cristobal (eoastal arid zone and above 500 m

alt.) and Santa Fe. We eannot deteet a preferenee for a eertain kind of vegetation zone, as most islands

are low in altitude.

Eustala meridionalis sp. nov.

um:lsid:zoobank.org:aet:AAB212Bl-16FA-4110-8133-7BB2EEE7FB52

Figs 4 A-C, 5 B, 6 B, 7

Eustala vegeta (Keyserling, 1865) - Baert, Maelfait, Hendriekx & Desender 2008: 47, map 15

(misidentifieation).

Fi/Va/a sp.-Baert 2013: 176, 178.

Diagnosis

Male: Differing from E. occidentalis and E. orientalis in the strueture of the terminal apophysis, whieh

is flat and broadening towards tip, apieal ridge being slightly longer than eaudal ridge. The female

differs from both speeies by having a shorter and thieker seapus.

Etymology

The speeies name refers to its distribution in the southern part of the arehipelago.

Type material

Holotype

S, ISFA FFORFANA, Cerro Pajas at the edge of Scalesia forest, alt. 335 m, 18 Apr. 1996 (P.96/55),

leg. S. Peek.

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

Allotype

ISLA FLOREANA, SE slope of Cerro Pajas, Scalesiapedunculata with undergrowth of Tournefortia

rufo-sericea and Croton scouleri, alt. 360 m, 20 Feb. 1977, leg. W.G. Reeder.

Paratypes

ISEAFEOREANA: 3 (?(?, 1 (?), SE slope of Cerro Pajas, alt. 360 m, 20 Feb. 1977 (leg. W.G. Reeder);

1 3, Base of Cerro Pajas, Scalesia forest, alt. 300 m, 16 Apr. 1996 (P.96/62) (leg. S. Peek); 1 j$,

along road towards top of the island, transition to Scalesia woodland, vegetation mainly eonsisting of

Tournefortia rufo-sericea and Scalesia pedunculata, thin shrub undergrowth, alt. 300 m, 22 Feb. 1988

(B.88/332) (leg. Baert, Maelfait & Desender).

RBINS inventory number of all type material is LG. 32723.

Description

Male (holotype)

LENGTH. Total length 5.02; earapaee length 2.71, width 2.55, height 0.75; abdomen length 3.14, width

2.39, height 1.96.

Fig. 4. Eustala meridionalis sp. nov. A. 3 left palp, ventral view. B. $ epigyne seapus, ventral view. C.

$ seapus, lateral view. Seale lines = 0.5 mm.

European Journal of Taxonomy 86 : 1-18 ( 2014 )

Fig. 5. Electron microscopic photographs of S left palp. A. Eustala occidentalis sp. nov. B. Eustala

meridionalis sp. nov. C. Eustala orientalis sp. nov. Scale lines = 0.1 mm.

Carapace. Colour (in alcohol) yellowish with black suffused striae and marked yellow V in cephalic

region; two short combs of long, white hairs diverge from between PME and PEE. Chelicerae black with

yellowish inner sides. Eabium black with white apical edge. Endites black with white apical and inner

margins. Sternum light yellow with broad, blackish suffused border. Pedipalps dark. Eegs pale yellow

with black annulations, variable among specimens; coxae and proximal part of femora whitish.

Abdomen. Dorsum greyish, speckled with cream spots; area between the converging waved brown lines

darker grey. Venter light yellow, suffused with grey. Colulus and spinnerets black.

Eyes. MOQ: PME = 0.73 AME. Cl = 0.63 DAME.

Fig. 6. Electron microscopic photographs of terminal apophysis of S left palp. A. Eustala occidentalis

sp. nov. B. Eustala meridionalis sp. nov. C. Eustala orientalis sp. nov. Scale lines = 0.1 mm.

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

Legs. Measurements:

I (13.25): Fe 4.04, Pa 1.37, Ti 3.33, Mt 3.22, Ta 1.29

11(10.29): Fe3.14, Pa 1.18, Ti 2.24, Mt 2.63, Ta 1.10

III (6.05): Fe 2.16, Pa 0.82, Ti 1.18, Mt 1.22, Ta 0.67

IV (9.22): Fe 3.14, Pa 1.14, Ti 1.96, Mt 2.16, Ta 0.82

Spination. All legs with numerous spines.

Pedipalp (Figs 4A, 5B). One very long patellar seta, a bit shorter than bulbus. Cymbium with eonspieious,

rounded, T-like tarsal hook. Terminal apophysis (Fig. 6B) flat and broadening towards tip, apieal ridge

of terminal apophysis being slightly longer than eaudal ridge.

Female (allotype)

EENGTH. Total length 8.49; earapaee length 3.53, width 2.86, height 1.37; abdomen length 5.18, width

4.90, height 3.76.

Carapace. Cream with some faint brown stains in eephalie area; eyes with blaek rings. Chelieerae

eream. Labium yellow brown with white apieal edge. Endites yellow brown with white apieal and inner

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

meridionalis sp. nov.

European Journal of Taxonomy 86 : 1-18 ( 2014 )

edges. Sternum whitish with broad, yellowish brown border. Legs yellowish brown with annulations

fainter than in male.

Abdomen. Dorsum lighter than in male; venter eream with three white stains. Colulus and spinnerets

blaek with orange tinge.

Eyes. MOQ: PME = 0.92 AME. Cl = 0.80 DAME.

Eegs. Measurements:

I (14.66): Fe 4.43, Pa 1.76, Ti 3.45, Mt 3.57, Ta 1.45

II (12.32): Fe 3.65, Pa 1.65, Ti 2.75, Mt 2.94, Ta 1.33

III (7.84): Fe 2.51, Pa 1.49, Ti 1.53, Mt 1.49, Ta 0.82

IV (10.98): Fe 3.69, Pa 1.53, Ti 2.35, Mt 2.43, Ta 0.98

Epigyne (Fig. 4 B-C). Seapus 0.35 mm long, 0.21 mm thiek, F/D = 1.67. Spermatheeae separated;

seapus broader at tip (in ventral view), straight and very broad in the middle (in lateral view).

Variation

The few males in our samples vary between 4.70 and 5.90 mm in length. The male eaught at the base of

Cerro Pajas (P.96/62) shows the same two broad white spots as some E. occidentalis sp. nov. speeimens

(see eolour pattern C of E. occidentalis sp. nov.. Fig. 2C). The other males all have a mueh lighter

appearanee. Their abdomen has more white and their eephalothorax is as light as that of the female

allotype.

Distribution

E. meridionalis sp. nov. has only been found above 300 m alt. in the Scalesia zone of Cerro Pajas and its

vieinity on the eentrally loeated southern island Floreana (Fig. 7).

Discussion

The three Eustala speeies deseribed here differ eonsistently from all mainland speeies: the males by

the shape of the palpal terminal apophysis, the females by the shape of the epigyne seapus and the

eonfiguration of the spermatheeae.

Chiekering (1955) previously wrote that the eolour pattern of the Central Ameriean Eustala speeies

is highly variable. He therefore did not attribute mueh importanee to this eharaeter in his speeies

deseriptions. This observation was later eorroborated by Fevi (1977: 96) in his generie diagnosis of

Eustala. “Most speeies are variable in eolouration with dark and light individuals, but most have a

folium pattern on the dorsum, exeeptions being some speeimens of E. anastera that are eontrastingly

eoloured with blaek patehes on white in aleohol (figs. 219, 222)”. The eolour patterns as given here by

Fevi eoineide strikingly with the patterns observed in Eustala speeies from Galapagos (Fig. 2, patterns

A-B and E).

The three speeies show a very distinetive segregated distribution over the arehipelago. E. occidentalis sp.

nov. has the broadest range over the eentral (Santa Cruz), the western (Santiago, Isabela and Femadina)

and two of the northern islands (Pinta and Marehena). This part of the arehipelago is younger than

2.3 my (Geist et al. 2013). E. meridionalis sp. nov. lives on the isolated southern island of Floreana

whieh has an age between 1.5 and 2.3 my (Geist et al. 2013). E. orientalis sp. nov. shows a peeuliar

distribution whieh 1 eannot explain. Its presenee on the eastern islands San Cristobal and Fspanola

may be logieal and understandable, these islands being the oldest ones (between 2.4 and 4.0 My, Geist

et al. 2013). But its presenee on the “eastern” islands Santa Fe and Genovesa is less explieable, sinee

BAERT L., Three wem Eustala (Araneae) speeies from the Galapagos Island

the distanee separating Santa Fe and Santa Cruz, where E. occidentalis sp. nov. lives, hardly exeeeds

17.5 km. Moreover, Genovesa belongs to the very young northern islands (age between 0.3 and 0.8 my

aeeording to Geist et al. 2013), lying on a straight line north of Santa Fe along the 90° W longitude, at

a distanee of approximately 125 km, but only some 50 km east of the eentral northern island Marehena.

Odo desenderi Baert, 2009 has a similar distribution. It oeeurs on Santa Fe and Genovesa but in an

inexplieable way also on Marehena.

Eustala speeies are, like most araneids, probably good ballooners, whieh ean easily be transported by

wind. One should expeet E. orientalis sp. nov. to be able to bridge the short northwest distanee between

Santa Fe and Santa Cruz, and to be found on that eentral island. This has apparently not happened,

although the prevailing winds eome from the southeast.

The distribution ofE. orientalis sp. nov. on the older southeastern islands andF. occidentalis sp. nov. on

the younger eentral and northwestern islands fits the line of the progression rule pattern, paralleling the

geologieal formation of the islands (Wagner & Funk 1995; Parent et al. 2008).

Natural History

Eustala speeies are apparently noetumal (Fevi 1977: 97) and remove their web during daytime. They

seem to have no retreat, but rest on a braneh of the vegetation in whieh they live (Fevi 1977: 97).

They were mostly eaught by sweeping in daytime and were sometimes eaught at night.

Acknowledgements

Field assistanee has been given by Jean-Pierre Maelfaitf (1982-2002), Konjev Desenderf (1982-2000),

Frederik Hendriekx (2002, 2010) and Wouter Dekoninek (2009, 2010) (Belgium); Stewart Peek & John

Heraty (Canada); Heimieh & Irene Sehatz (Austria); Sandra Abedrabbo, Sonja Sandovall, Germania

Estevez, Fazaro Roque and Henri Herrera (Eeuador).

We reeeived logistie and teehnieal support from the Charles Darwin Researeh Station (CDRS) and the

Parque Naeional de Galapagos (SPNG). Finaneial support was provided by the Belgian State (now

Belspo), FWO and the Feopold III Fund.

Thanks go to James Reddell of the Texas Memorial Museum (University of Texas) for the loan of the

spider eolleetions made by W.G. Reeder, to Janet Beeealoni of the Natural History Museum of Fondon

for the loan of the type speeimens of Eustala vegeta (Keyserling, 1865) and to Faura Feibensperger of

the Harvard University Museum of Comparative Zoology for the loan of various Eustala speeies.

Speeial thanks go to Marylise Feelereq who made all the drawings. I further thank Julien Cillis who

made the SEM-photographs and Alain Pauly who made the eolour photographs.

This publieation is eontribution number 2091 of the Charles Darwin F oundation for the Galapagos Islands.

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Manuscript received: 16 January 2014

Manuscript accepted: 24 April 2014

Published on: 5 June 2014

Topic editor: Rudy Joeque

Desk editor: Kristiaan Hoedemakers

Printed versions of all papers are also deposited in the libraries of the institutes that are members of the

EJT eonsortium: Museum National d’Histoire Naturelle, Paris, Franee; Botanie Garden Meise, Belgium;

Royal Museum for Central Afriea, Tervuren, Belgium; Natural History Museum, Eondon, United

Kingdom; Royal Belgian Institute of Natural Seienees, Brussels, Belgium; Natural History Museum of

Denmark, Copenhagen, Denmark.