Eustala meridionalis, 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 : 12-16

Eustala meridionalis sp. nov.

urn:lsid:zoobank.org:act:AAB212B1-16FA-4110-8133-7BB2EEE7FB52

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

Eustala vegeta (Keyserling, 1865) – Baert, Maelfait, Hendrickx & Desender 2008: 47, map 15 (misidentiFcation).

Eustala sp. – Baert 2013: 176, 178.

Diagnosis

Male: Differing from E. occidentalis and E. orientalis in the structure of the terminal apophysis, which is Fat and broadening towards tip, apical ridge being slightly longer than caudal ridge. The female differs from both species by having a shorter and thicker scapus.

Etymology

The species name refers to its distribution in the southern part of the archipelago.

Type material

Holotype

Ƌ, ISLA FLOREANA, Cerro Pajas at the edge of Scalesia forest , alt. 335 m, 18 Apr. 1996 (P.96/55), leg. S. Peck .

Allotype

♀, ISLA FLOREANA, SE slope of Cerro Pajas, Scalesia pedunculata with undergrowth of Tournefortia rufo-sericea and Croton scouleri , alt. 360 m, 20 Feb. 1977, leg. W.G. Reeder .

Paratypes

ISLA FLOREANA: 3 ƋƋ, 1 (♀), SE slope of Cerro Pajas , alt. 360 m, 20 Feb. 1977 (leg. W.G. Reeder) ; 1 Ƌ, Base of Cerro Pajas, Scalesia forest , alt. 300 m, 16 Apr. 1996 (P.96/62) (leg. S. Peck) ; 1 j ♀, along road towards top of the island, transition to Scalesia woodland, vegetation mainly consisting 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 I.G. 32723.

Description

Male (holotype)

LENGTH. Total length 5.02; carapace length 2.71, width 2.55, height 0.75; abdomen length 3.14, width 2.39, height 1.96.

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 PLE. Chelicerae black with yellowish inner sides. Labium black with white apical edge. Endites black with white apical and inner margins. Sternum light yellow with broad, blackish suffused border. Pedipalps dark. Legs 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.

LEGS. Measurements:

I (13.25): Fe 4.04, Pa 1.37, Ti 3.33, Mt 3.22, Ta 1.29 II (10.29): Fe 3.14, 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 4 A, 5B). One very long patellar seta, a bit shorter than bulbus. Cymbium with conspicious, rounded, T-like tarsal hook. Terminal apophysis ( Fig. 6 B) Fat and broadening towards tip, apical ridge of terminal apophysis being slightly longer than caudal ridge.

Female (allotype)

LENGTH. Total length 8.49; carapace 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 cephalic area; eyes with black rings. Chelicerae cream. Labium yellow brown with white apical edge. Endites yellow brown with white apical and inner edges. Sternum whitish with broad, yellowish brown border. Legs yellowish brown with annulations fainter than in male.

ABDOMEN. Dorsum lighter than in male; venter cream with three white stains. Colulus and spinnerets black with orange tinge.

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

LEGS. 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). Scapus 0.35 mm long, 0.21 mm thick, L/D = 1.67. Spermathecae separated; scapus 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 caught at the base of Cerro Pajas (P.96/62) shows the same two broad white spots as some E. occidentalis sp. nov. specimens (see colour pattern C of E. occidentalis sp. nov., Fig. 2 C). The other males all have a much lighter appearance. Their abdomen has more white and their cephalothorax 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 vicinity on the centrally located southern island Floreana ( Fig. 7 ).

Figures

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. 4. Eustala meridionalis sp. nov. A. Ƌ left palp, ventral view. B. ♀ epigyne scapus, ventral view. C. ♀ scapus, lateral view. Scale lines = 0.5 mm.

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.