Mecaphesa reddelli, 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 : 8-11

Mecaphesa reddelli sp. nov.

urn:lsid:zoobank.org:act:A1438F2A-8FE2-4BD9-822C-3667F88CED3B

Figs 2A-C , 3B, 9E-F

Diagnosis

Males of M. reddelli can be recognized by the palpal tibia bearing one dorsal and four pro-lateral spines, RTA with smooth slightly curved tip (strongly hooked in M. inclusa ), a short curved VTA (inconspicuous in M. inclusa ). Females differ from those of other species by its pentagonal shaped epigyne cavity with lobate anterior borders (cavity oval shaped in M. inclusa ).

Etymology

The species is named after James Reddell of the Texas Memorial Museum who gave me the opportunity to study the spiders caught by W. G. Reeder during his various collecting trips between 1975 and 1980.

Type material

Holotype

♂, ISLA SANTA CRUZ , Cerro Colorado , 20 m alt., from Scalesia litter at 200-300 m SW of base of Cerro , 13 Mar. 1975, leg. W.G. Reeder .

Allotype

♀, ISLA ISABELA , Volcán Alcedo , Pega Pega Camp , 783 m alt., from large Waltheria bush in the Scalesia savannah , 13 May 1980, leg. W.G. Reeder .

Paratypes

ISLA SANTA CRUZ : 1 ♂, Cerro Colorado , 10 m alt., 11 Mar. 1975, leg. W.G. Reeder .

ISLA ISABELA : 1 ♀, Volcán Darwin , outside slope Beagle crater , 40-50 m alt., beating Acacia rorudiana , 22 May 1980, leg. W.G. Reeder .

ISLA GENOVESA : 1 ♀, 1 juv., 500 m from SE-crater rim , 50 m alt., 25 Oct. 1975, leg. W.G. Reeder .

ISLA PINTA : 1 ♀, pampa , 400 m alt., 18 Jul. 1977, leg. W.G. Reeder .

Description

Male holotype

TOTAL LENGTH. 3.45; prosoma length: 1.53, width: 1.61, height: 0.49; chelicerae: 0.54; opisthosoma length: 2.06, width: 1.40, height: 1.07.

PROSOMA. With long setae arranged in three rows, one just behind posterior eyes and 2 rear oblique rows ( Fig. 9G ); lateral borders of entire prosoma provided with very short setae; clypeus with a row of 7 setae; anterior and posterior lateral eyes on tubercle, PE directed backwards; chelicerae with a proximal median long seta; coxae with dorsal setae.

OPISTHOSOMA. With many long setae.

COLOUR. Prosoma: orange brown with triangular lighter area behind the posterior eyes, eye region whitish; chelicerae, labium, endites and sternum orange brown. Legs I & II: yellow brown; Ti, Mt and Ta with dark brown distal end (Mt for 2/3th brown). Legs III & IV: yellow. Opisthosoma: creamy with white stains and irregular rows of black stains (6 are very obvious in caudal part) on dorsum ( Fig. 9F ).

EYES. MOQ: AW = 0.85 PW, AW = 0.89 LAP, Cl = 3.4 DAME, DALE = 0.16.

LEGS. Measurements: I (9.89): Fe 2.75, Pa 0.94, Ti 2.16, Mt 1.96, Ta 1.02; II (8.43): Fe 2.59, Pa 0.94, Ti 2.08, Mt 1.84, Ta 0.98; III (3.97): Fe 1.24, Pa 0.52, Ti 0.89, Mt 0.76, Ta 0.56; IV (4.04): Fe 1.26, Pa 0.49, Ti 0.93, Mt 0.80, Ta 0.56. Spination: Fe I: d2pl3, Fe II: d2-3, Fe III: d2, Fe IV: d2; Pa I-II: d0, P III-IV: d2; Ti I-IV: d2. Pa III & IV with 2 dorsal spines.

PALP. ( Fig. 2A, B ) Tibia with 1 dorsal and 4 pro-lateral spines; RTA with smooth slightly curved tip; short curved VTA. Embolus with retro-lateral origin, slightly curled at tip. Cymbium without tutaculum or tutacular groove; 2 pro-lateral spines. Length of cymbium: 0.52.

Female allotype

TOTAL LENGTH. 3.61; prosoma length: 1.76, width: 1.75, height: 0.45; chelicerae: 0.56; opisthosoma length: 2.37, width: 1.88, height: 1.28.

OPISTHOSOMA. Without long setae as in male.

COLOUR. Prosoma: cephalic region (clypeus and eye area) white; thorax region light brown with median dorsal white area connected to cephalic region by means of white longitudinal stripes; prosoma border white. Two strong setae behind each PLE. Chelicerae, endites and sternum: light brown with whitish tinge. Labium: light brown. Legs: light brown with whitish tinge; distal borders of Fe, Pa and Ti white. Opisthosoma: dorsum white with 4 pairs of black dots of which the central 4 largest ( Fig. 9E ); sides creamy white; venter whitish; spinnerets whitish.

EYES. MOQ: AW = 0.74 PW, AW = 0.84 LAP, Cl = 3.4 DAME, DALE = 0.16.

LEGS. Measurements: I (7.29): Fe 2.29, Pa 1.01, Ti 1.71, Mt 1.46, Ta 0.82; II (7.13): Fe 2.29, Pa 0.97, Ti 1.59, Mt 1.46, Ta 0.82; III (3.52): Fe 1.11, Pa 0.54, Ti 0.72, Mt 0.66, Ta 0.49; IV (3.85): Fe 1.22, Pa 0.52, Ti 0.82, Mt 0.78, Ta 0.51. Spination: Fe I: d2pl2, Fe II: d2-3, Fe III-IV: d2; Ti I-II: d2v 2 pairs of 4 spines; Mt I-II: d2pl1rl1v2 pairs of 5 spines. Pa III & IV without 2 dorsal spines as in male.

EPIGYNE. Shape of epigyne cavity pentagonal with anterior borders slightly protruding; width of epigyne cavity: 0.17 ( Fig. 2C ); not very conspicuous small vulva compared to M. inclusa , small spermatheca with short copulatory ducts ( Fig. 3B ).

Male Paratype

TOTAL LENGTH. 3.02; prosoma length: 1.50, width: 1.59, height: 0.49; chelicerae: 0.43; opisthosoma length: 1.81, width: 1.26, height: 0.89.

COLOUR. Prosoma: As holotype but eye region not whitish.

EYES. MOQ: AW = 0.85 PW, AW = 0.90 LAP, Cl = 3.4 DAME, DALE = 0.16.

LEGS. Measurements: I (8.43): Fe 2.59, Pa 0.94, Ti 2.04, Mt 1.88, Ta 0.98; II (7.91): Fe 2.39, Pa 0.90, Ti 1.92, Mt 1.76, Ta 0.94; III (3.70): Fe 1.15, Pa 0.52, Ti 0.83, Mt 0.70, Ta 0.50; IV (3.78): Fe 1.20, Pa 0.45, Ti 0.85, Mt 0.76, Ta 0.52. Spination: Fe I: d2pl2, Fe II: d2-3, Fe III: d2, Fe IV: d2; Pa I-II: d0, P III-IV: d2; Ti I-IV: d2.

Colour variation in females

The females from Isla Isabela (Volcán Alcedo and Volcán Darwin) are very similar in colour. Those of the northern islands (Pinta and Genovesa) differ from those of Isla Isabela in the following respects: the thoracic dorsal white area is flanked with a broad dark brown band in the Pinta female, while the Isla Genovesa female and juvenile female are in general more brownish.

Distribution

Santa Cruz, Volcán Alcedo and Darwin (Isla Isabela), Genovesa and Pinta. It was caught at different altitudes.

Figures

Fig. 2. Mecaphesa reddelli sp. nov. A. ♂ palp, ventral view. B. ♂ palp, retrolateral view. C. ♀, epigyne.

Fig. 9. Habitus. — A-D. Mecaphesa inclusa (Banks, 1902). A. ♂ colour type A. B. ♂ colour type B. C. ♂ colour type C. D. ♀ colour type C. — E-F. Mecaphesa reddelli sp. nov. E. ♀ of Volcán Alcedo (Isla Isabela). F. ♂ of Volcán Alcedo (Isla Isabela). Scale bars: 1 mm. Photographs by Rudy Jocqué.

Fig. 3. — A. Mecaphesa inclusa (Banks, 1902), spermathecae. — B. M. reddelli sp. nov., spermathecae.