Tmarus galapagosensis, Baert, L., 2013

Baert, L., 2013, The Thomisidae and Philodromidae (Arachnida: Araneae) of the Galápagos Islands (Ecuador), European Journal of Taxonomy 43, pp. 1-23 : 11-16

Tmarus galapagosensis sp. nov.

Tmarus stolzmanni – Keyserling, 1880: 138, pl. 3, fig. 74 (description ♂). — Banks 1902: 62, pl. 1, fig. 5 (description ♂). — Lubin 1983: 18; 1984: 240; 1985: 795. — Baert & Maelfait 1986: 119, map 25; 2000: 244. — Baert, Maelfait & Desender 1988: 50, 53; 1989: 22. — Baert, Maelfait, Hendrickx & Desender 2008: 67, map 150.

Diagnosis

Males of T. galapagosensis can be recognized by the RTA with a curled tip and a dark curved hook at its base, and by the shape of the embolus which arises from the centre of the tegulum making three turns in retrolateral direction. Females differ from other Tmarus species by the rounded scapus-like plate without atrium ( Fig. 5B, C ), the subspherical spermathecae and the strongly curled copulatory ducts ( Fig. 5D ).

Etymology

The species name is derived from the geographic name Galápagos, as this species has a wide distribution throughout the archipelago.

Type material

All type material deposited at the RBINS.

Holotype

♂, ISLA SANTA CRUZ , vicinity of Cueva Andreas, arid zone , 20 m alt., 7 Apr. 1991, leg. L. Baert, J.-P. Maelfait & K. Desender .

Allotype

♀, ISLA FERNANDINA , Punta Espinosa , 24 Mar. 1988, leg. L. Baert, J.-P. Maelfait & K. Desender .

Paratypes

ISLA MARCHENA : 1 ♂, Playa Negra , Bursera forest , 5 m alt., 10 Mar. 1988, leg. L. Baert, J.-P. Maelfait & K. Desender ; 1 ♂, SW Playa, Bursera forest , 30 m alt., 12-24 Mar. 1992, leg. S. Peck ; 4 ♂ ♂, 4 ♀ ♀, 3 juv., S-slope near beach camp , 5-10 m alt., night catch in Croton vegetation, 26 Jan. 1977, leg. W.G. Reeder .

ISLA ISABELA : 3 ♂, 1 ♀, 2 (♀), Volcán Darwin , Beagle crater , night catch, 22 May 1980, leg. W.G. Reeder .

ISLA SANTA CRUZ : 1 ♀, arid zone , Sep. 1964, leg. J. & N. Leleup .

Other material examined

ISLA FERNANDINA : (♀), Tail to Bursera Hills (West vegetation strip) , 125 m alt., 27 Apr. 1975 ; ♀, 3 juv., West vegetation strip (ash delta stream bed) , 30 m alt., 11 Aug. 1977, leg. W.G. Reeder. ISLA FLOREANA : ♀, Post Office Bay , arid zone , 20-30 Nov. 1925, ZMUN .

ISLA ISABELA : VOLCÁN SIERRA NEGRA : ♂, ♀, 3 juv., road to the highlands (500 m from sea) , 0-3 m alt., 11 Jan. 1978 ; ♂, ♀, near Villamil (road to the highlands, 1 km from sea) , 10-15 m alt., 11 Aug. 1978, (eg. W.G. Reeder . VOLCÁN ALCEDO : low arid zone , 5 m alt., new trail , 26 Oct.-2 Nov. 2001, leg. L. Roque ; (♂), open Palo Santo wood, along old trail, Bursera vegetation , 200 m alt., 2-4 Apr. 1996, leg. L. Baert, J.-P. Maelfait & K. Desender ; ♀, Bursera camp , 340 m alt., 19 May 1980 ; 3 ♂, ♀, 3 (♂), 3 (♀), 2 juv., E-slope, W of lava flow , 380 m alt., 23-25 May 1980 ; 2 ♂, 4 ♀, (♂), (♀), 3 juv., E-slope , 600 m alt., 24 May 1980, leg. W.G. Reeder . VOLCÁN DARWIN : (♂), Tagus Cove trail , 0-20 m alt., 2 May 1975 . BEAGLE CRATER : 2 ♂ ♂, 3 juv., lava field between Beagle crater and volcano , 40-50 m alt., 22 May 1980 ; ♂, 5 ♀♀, (♂), (♀), 7 juv., camp site , 22 May 1980, leg. W.G. Reeder ; juv., outer Western crater flank, Bursera vegetation , 20 m alt., 22 Feb. 1982, leg. L. Baert & J.-P. Maelfait . VOLCÁN ECUADOR : ♀, (♀), juv., Cabo Berkeley , between 20 and 90 m alt., 8 Aug. 1977, leg. W.G. Reeder .

ISLA MARCHENA : ♀, 2 (♀♀), SW slope beach camp area , 10-20 m alt., 30 Jan. 1977 ; 2 juv., South playa camp, 10 m of new lava flow , 16-20 m alt., 1 Feb. 1977 ; juv., near Barranco fumaroles , 160-190 m alt., 29 Jan. 1977 ; ♂, 2♀♀, ♂, S-slope, near fumaroles ridge , 190 m alt., 26 Jan. 1977, leg. W.G. Reeder ; Punta Espejo, Bursera vegetation , 5 m alt., 11-24 Mar. 1992 ; ♂, (♂), 2 juv. Playa Negra, steppe forest at 30 m alt., 12-24 Mar. 1992, leg. S. Peck .

ISLA PINTA : 3 ♂, 2 ♀, juv. 1 km NE of South Playa , 17-22 Jan. 1977, leg. W.G. Reeder ; transition zone , 200 m alt., 14-22 Mar. 1992, leg. S. Peck .

ISLA PINZON : ♂, 55-70 m alt., 2 Feb. 1975 ; ♂, old crater camp , 320 m alt., 5 Feb. 1979, leg. W.G. Reeder ; (♂), Opuntia field near crater , 300 m alt., 25 Jan. 2010, leg. F. Hendrickx .

ISLA SANTIAGO : juv., Caleta Bucanero , Coldenia vegetation, 30 m alt., 9 Apr. 1982 ; 2 juv., Cerro Cowan , 260 m alt., 7 Apr. 1982, leg. L. Baert & J.-P. Maelfait ; ♂, juv., Caleta Bucanero , 25 m alt., 10 Sep. 1975 ; (♂), juv., Caleta Bucanero, lava ridge , 40-50 m alt., 19 Apr. 1975 ; ♂, Crater area , 820- 850 m alt., 14 Sep. 1975, leg. W.G. Reeder ; ♂, E-slope , 160 m alt., 16 Apr. 1964, CAS ; (♂), juv., Los Guayabillos , 300 m alt., 14-16 May 1982, CDRS ; ♂, 2 ♀, Los Guayabillos , 300 m alt., 6-7 Apr. 1982, CDRS .

ISLA SANTA CRUZ : ♂, ♀, Academy Bay , 17.Oct.1969 (leg. S. Riechert) .

ISLA SANTA FE : ♀, camp area , 5-10 m alt., 23 Jan. 1979, leg. W.G. Reeder ; 2 juv. Highland , 100 m alt., 11-24 Mar. 1996, leg. S. Peck ; (♀), Highland , 150 m alt., 24 Apr. 1991, leg. L. Baert, J.-P. Maelfait & K. Desender ISLA WOLF : juv., 2 Feb. 2002, CDRS Material is deposited either at the RBINS (collections made by L. Baert et al., F. Hendrickx and S. & J. Peck), TMM (collections made by W.G. Reeder and S. Riechert), CDRS (collections made by L. Roque and collaborators), CAS or ZMUN.

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Cited in the literature

ISLA ISABELA : 2 ♂ ♂, Tagus Cove , March 1899 ( Banks 1902) .

ISLA FLOREANA : juv., 29 Oct. & 20-30 Nov. 1925 ( Banks 1930) .

ISLA SANTIAGO : numerous specimens, Los Guyabillos , 300 m alt. ( Lubin 1983, 1984, 1985) .

Description

Male holotype

TOTAL LENGTH. 3.49; prosoma length: 1.35, width: 1.27, height: 0.68; opisthosoma length: 2.03, width: 1.07, height: 0.93; clypeus: 0.29; chelicerae: 0.49.

OPISTHOSOMA. Egg-shaped with small caudo-dorsal, sharp backwards-directed conical hump.

COLOUR. Prosoma: basic colour brown with white striae (darker than in female); MOQ and clypeus white connected to each other by a white stripe, eye tubercles with LE white encircled, slightly sloping clypeus bordered by a white stripe; dorsum creamy bordered by a white triangle, with some short and long spines. Clypeus with 5 spines (2 at border just above chelicerae and 1 centrally halfway). Chelicerae white with central creamy brown area, 2 long proximal spines and a row of 4 short spines along inner edge. Labium, endites and sternum creamy brown. Palp creamy with white stains, cymbium white. Legs: yellowish with few white and brownish stains. Opisthosoma: dorsum white, sides in apical half dusty, in caudal half white; venter creamy brown bordered by a white band; spinnerets white with brown spots.

EYES. MOQ: AW = 0.66 PW; AW = 0.66 LAP; Cl = 7.25 DAME; DAME = 0.04 DALE = 0.14.

LEGS. Measurements: I (7.56): Fe 2.23, Pa 0.78, Ti 1.84, Mt 1.81, Ta 0.90; II (6.91): Fe 2.00, Pa 0.70, Ti 1.73, Mt 1.61, Ta 0.87; III (3.42): Fe 0.97, Pa 0.41, Ti 0.87, Mt 0.64, Ta 0.53; IV (3.32): Fe 1.07, Pa 0.41, Ti 0.72, Mt 0.58, Ta 0.54. Spination: Fe I: 2d5pl2rl, Fe II: 3d3pl1rl, Fe III: 2d1pl, Fe IV: 2d; Ti I: 2d3pl3rl2-2v, Ti II: 2d3pl3rl2-2v, Ti III: 2d, Ti IV: 2d; Mt I: 1rl 2-1-1v, Mt II: 1rl2-2v. Mt and Ta I-IV with distal row of 3 trichobotria.

PALP. ( Fig. 4A, B) Cymbium with 5 spines (2 prolateral, 1 central and 2 in retrolateral position). Tibia with 1 dark hook, 1 spine and 2 trichobotria in retrolateral position, 3 dorsal trichobotria and 2 spines in prolateral position; RTA with curled tip and dark curled hook at base; broad lobe-like VTA. Embolus arising centrally of tegulum, making three turns in retrolateral direction. Cymbium = 0.49.

Female allotype

TOTAL LENGTH. 5.14; prosoma length: 1.74, width: 1.59, height: 0.75; opisthosoma length: 3.33, width: 1.98, height: 1.92; clypeus: 0.35; chelicerae: 0.66.

OPISTHOSOMA. Egg-shaped with conspicuous caudo-dorsal blunt, backwards-directed conical hump ( Fig. 5A ).

COLOUR. Whiter than male. Prosoma: white with faint brown striae; clypeus white, slightly sloping. Chelicerae, labium, endites, sternum and pedipalp: white with brown stains. Legs: yellow sparsely mottled with brown dots. Opisthosoma: dorsum and sides white, sparsely mottled with creamy brown stains; venter creamy brown band; spinnerets white with brown spots.

EYES. MOQ: AW = 0.63 PW; AW = 0.71 LAP; Cl = 5.8 DAME; DAME = 0.06, DALE = 0.17.

LEGS. Measurements: I (7.45): Fe 2.29, Pa 0.87, Ti 1.75, Mt 1.61, Ta 0.93; II (7.01): Fe 2.12, Pa 0.85, Ti 1.61, Mt 1.50, Ta 0.93; III (4.16): Fe 1.17, Pa 0.58, Ti 1.01, Mt 0.76, Ta 0.64; IV (4.23): Fe 1.38, Pa 0.54, Ti 0.91, Mt 0.76, Ta 0.64. Spination: Fe I: 1d5pl1rl, Fe II: 2-3pl1rl, Fe III: 2d2pl; Ti I: 2d2pl2rl2- 1-2v, Ti II: 2d2pl2rl2-1v, Ti III: 2d1v; Mt I: 2-2-1-1-2-2v, Mt II: 2-2-2v. Mt and Ta I-IV with distal row of 3 trichobotria.

EPIGYNE. A rounded scapus-like plate ( Fig. 5 B-C ). Two big, nearly spherical spermathecae and strongly curled long copulatory ducts; fertilisation ducts short ( Fig. 5D) , length of scapus: 0.35.

Biology

Ant-eating nocturnal habit ( Lubin 1983). Highly cryptic species, perfectly blending with the background of dry twigs covered with lichens, on which it sits during daytime. The pronounced abdominal dorsal hump gives the spider the appearance of a small protuberance or leaf scar on a twig ( Lubin 1983).

Figures

Fig. 5. Tmarus galapagosensis sp. nov., ♀. A. Lateral view. B-C. Epigyne. D. Spermathecae.

Fig. 4. — A-B. Tmarus galapagosensis sp. nov., ♂. A. Palp, ventral view. B. Palp, retrolateral view. — C-D. Tmarus stolzmanni Keyserling, 1880, ♂. C. Palp, ventral view after Keyserling (1880). D. Palp, ventral view after Banks (1902).