Mesabolivar uruguayensis, Machado, Éwerton O., Laborda, Álvaro, Simó, Miguel & Brescovit, Antonio D., 2013

Machado, Éwerton O., Laborda, Álvaro, Simó, Miguel & Brescovit, Antonio D., 2013, Contributions to the taxonomy and distribution of the genus Mesabolivar in southern South America (Araneae: Pholcidae), Zootaxa 3682 (3), pp. 401-411 : 408-411

Mesabolivar uruguayensis new species

Figs 31–40 .

Holotype. Male holotype from Paysandú ciudad, Paysandú, Uruguay (32°19’ S; 58°04’ W), 07.I.2007, in FCE 2432. Paratypes: 1 female (FCE 2432) same data as holotype; 1 female ( IBSP 161829) from same locality, 01.IV.2007, A. Laborda leg.

Etymology. The specific name refers to the type locality.

Diagnosis. Similar to M. iguazu Huber, 2000 , the male sharing the pair of proximal projections and median apophysis at prolateral edge of chelicerae ( Figs 31–32 ), distinguished from congeners by the shape of procursus, straight with distinctive sclerotized tip ( Figs 33–34 ). The female, similar to M. iguazu and M. argentinensis (Mello- Leitão, 1938), can be distinguished by presence of one pair of projections in line with epigynal pocket, both close to posterior edge of epigynum ( Fig. 38 ).

Description. Male (Holotype). Total length 3.2, carapace length 0.9, clypeus 0.2, carapace width 1.1; leg I: 33.2 (8.1 + 0.6 + 7.9 + 13.0 + 3.6), tibia II: 5.1, tibia III: 3.8, tibia IV missing, tibia I L/d: 53. Carapace light brown with darker edges and medial longitudinal dark stripe; sternum light brown. Distinct thoracic groove. Eight eyes on slightly elevated ocular area; distance PME-ALE about 100% of PME diameter. Chelicerae light brown, basal segment with proximal apophysis and more distal medial apophysis at prolateral edge ( Figs 31–32 ). Palps as in Fig. 33 . Coxa with prominent retrolateral apophysis ( Fig. 33 ). Femur with rounded retrolateral proximal apophysis ( Fig. 33 ). Procursus light brown, straight, with prolateral spines in proximal region and microspinulation on distal region ( Figs 33–34 ). Distinct tip of procursus, sclerotized with distal membranous projection ( Figs 34–36 ). Bulb simple, without transparent projection ( Fig. 37 ), embolic division long and straight, membranous distally, sclerotized prolateral stripe present ( Fig. 37 ). Legs brown, femora with subterminal dark rings and tibia with lighter tips; legs without modified spines, vertical or curved hairs. Retrolateral trichobothrium on tibia I at 2.3%. Tarsus I without ventral serrated spines and approximately 24 pseudosegments. Abdomen oval, greenish with greenish-blue grouped spots.

Female (Paratype IBSP 161829). Total length 3.9, carapace 1.0, carapace width 1.2; leg I: 29.5 (7.8 + 0.5 + 7.5 + 11.9 + 1.8), tibia II: 4.9, tibia III: 3.6, tibia IV: 4.9, tibia I L/d: 44. In general similar to male. Legs brown, femora with subterminal dark rings and tibiae with lighter tips. Epigynum brown, slightly elevated, with one pair of lateral projections in one line with small epigynal pocket, both located close to posterior edge of epigynum ( Figs 38–39 ). Internal genitalia with two porous plates, longer than wide, connected by sclerotized region ( Fig. 40 ). Variation. Three males: carapace width 1.4–1.5; tibia I: 9.5–10.2. Three females: carapace width 1.2–1.3; tibia I: 6.6–7.6.

Distribution. North-eastern Argentina, southern Brazil and Uruguay ( Fig. 41 ).

Other material examined: BRAZIL: Rio Grande do Sul: Iraí (27°11ʹ38ʺS, 53°15ʹ0 3ʺW), 13, 21.XI.1975, A.A. Lise leg. (MCN 3059); ARGENTINA: Misiones: Santa María (27°55ʹS, 55°22ʹW), 1Ƥ, 1J, X.1944, Viana leg. (MCAN-Ar 19956); Entre Ríos: Parque Nacional El Palmar (31°54ʹS, 58°15ʹW), 13, 1Ƥ, 1J, 16–19.IV.1992, M. Ramírez leg. (MCAN-Ar 19931); URUGUAY: Salto: Grutas Arroyo San Antonio Grande (31°21ʹ0 4ʺS, 57°58ʹ56ʺW), 3Ƥ, 06.III.1981, M. Franca leg. (FCE 2212); Paysandú: 5 km from Paysandú city (32°21ʹ0 5ʺS, 58°03ʹ36ʺW), 33, 3Ƥ, 1j, 11.IV.2009, A. Laborda leg. (FCE 2840); Paysandú city (32°19ʹ21ʺS, 58°04ʹ12ʺW), 1Ƥ, 11.IV.2005, A. Laborda leg. (FCE 2839); Río Negro: Fray Bentos, Caballada Island (33°04ʹ59ʺS, 58°12ʹW), 13, 2Ƥ, 15.XII.2008, L. Montes de Oca leg. (FCE 2841); Near bridge "General San Martín" (33°07ʹ57ʺS, 58°17ʹ44ʺW), 33, 1Ƥ, 23.IX.2008, A. Laborda leg. (FCE 2842); Soriano: Mercedes, Barrientos Island (33°17ʹ0 7ʺS, 58°07ʹ12ʺW), 13, J. Olazarri leg. (FCE 2501).

Natural history. This species can be found in riparian forests and in urban sites, outside houses.

Figures

FIGURE 41. Known geographic distributions of Mesabolivar tandilicus, M. charrua sp. nov. and M. uruguayensis sp. nov..

FIGURES 31 – 40. Mesabolivar uruguayensis sp. nov.. 31 – 32, Male chelicerae, frontal (31), Lateral (32). 33, Male left palp, retrolateral. 34 – 36, Left procursus, prolateral (34), Tip, dorsal (35), Tip, retrolateral (36). 37, Left bulb, prolateral. 38 – 40, Epigynum, ventral (38), lateral (39), dorsal (40). Scale: 0.5 mm.