Ixchela grix, Valdez-Mondragón, Alejandro, 2013

Valdez-Mondragón, Alejandro, 2013, Taxonomic revision of the spider genus Ixchela Huber, 2000 (Araneae: Pholcidae), with description of ten new species from Mexico and Central America, Zootaxa 3608 (5), pp. 285-327 : 310-312

Ixchela grix new species

Figures 122–133

Type data. MEXICO: Oaxaca: 1 3 holotype (CNAN T0703) [3 May 2010; G. Montiel, M. Hernández, D. Barrales] from La Yerbabuena (lat 16.2666°, lon -97.3686°; 1710 m), Municipio Santa Catarina Juquila. Paratypes: 1 Ƥ (CNAN T0704), same data as holotype. 1 Ƥ (CNAN T0705) [1 May 2010; G. Montiel, M. Hernández, D. Barrales, R. Chavarría] from Ranchería La Yerbabuena (lat 16.2049°, lon -97.3569°; 1494 m), Municipio Santa Catarina Juquila.

Etymology. The specific name is a noun in apposition and dedicated to the acarologist and friend M. S. Griselda Montiel Parra “ Grix ” for her contribution to the knowledge of arachnids from Mexico and her participation in collecting the type series.

Diagnosis. Distinguished from congeners by the chelicerae with FAC rounded and small, directed toward prolateral part ( Figs 124, 126 ); and by the epigynum with small apophysis, conical and curved ( Figs 131, 133 ), square-shaped in ventral view ( Fig. 131 ).

Description. Male (Holotype). Prosoma: Carapace beige, with two long pale grey spots, laterally, near to the margin ( Fig. 123 ). Ocular region brown, with three inconspicuous lines projecting from posterior eyes to posterior part of the ocular region ( Fig. 123 ). Fovea with irregular grey region around it, this region does not touch the posterior part of ocular region ( Fig. 123 ). Clypeus pale yellow, with a wide longitudinal brown stripe, which has two lateral constrictions in middle part ( Fig. 126 ). Chelicerae dark brown ( Figs 124, 126 ). Sternum, labium and endites dark brown. Legs: Coxae pale yellow, orange on prolateral and retrolateral parts. Trochanters brown. Femora brown, paler basally, with a wide dark ring, sub-distally, conspicuous. Patellae dark gray. Tibiae, metatarsi and tarsi orange; tibiae with one basal conspicuous dark ring and one distal inconspicuous dark ring. Opisthosoma: Slightly conical, dark blue, as long as high ( Fig 122 ). Gonopore plate olive, trapezoidal. Palp: Femur pale orange, conical and slender, VAF small and inconspicuous ( Fig. 128 ). Patella and tibia orange. Procursus brown, conical, paler basally, with distal curved spine ( Figs 128, 129 ). VPP inconspicuous, with long setae, distal setae becoming larger ( Fig. 128 ). PAB long and slightly curved ( Fig. 129 ). Embolus long and conical, with dorsal spine and ventral projection with same length, and touching each other ( Figs 128, 129 ). Measurements: Total length 7.80. Carapace 3.40 long, 3.10 wide. Clypeus 1.25 long. Diameter AME 0.17, ALE 0.30, PME 0.24, PLE 0.26. Distance ALE- PME 0.22, PME-PME 0.36. Leg I: 58.44 (15.00+1.45+14.62+21.37+6.00), tibia II: 10.50, tibia III: missing, tibia IV: 10.62. Tibia I l/d: 23.40.

Female (Paratype). (CNAN T0704). Similar to the male, differences: Prosoma: The two long pale grey spots on carapace wider than on male. The three inconspicuous lines projected from posterior eyes toward posterior part of the ocular region not visibles. The wide and brown longitudinal stripe on clypeus straight, without median constrictions. Chelicerae brown, paler on basal and frontal part. Legs: Coxae beige, brown on prolateral and retrolateral parts. Femora, tibiae, metatarsi and tarsi pale brown. Rings on distal part of femora, and rings on basal and distal of tibiae, more marked than on male. Opisthosoma: Larger than high, more conical than the male. Epigynum: Slightly larger than wide, square in ventral view ( Fig. 131 ). PP larger than wide, with oval shape near to MSE ( Fig. 132 ). MSE with upside down Y-shape, the two sac-shaped concavities between MSE and PP large and thin ( Fig. 132 ). Measurements. Total length 7.80. Carapace 3.15 long, 2.95 wide. Clypeus 1.20 long. Diameter AME 0.16, ALE 0.28, PME 0.26, PLE 0.26. Distance ALE-PME 0.18. PME-PME 0.31. Leg I: 51.08 (12.75+1.35+13.50+17.68+5.80), tibia II: 9.37, tibia III: 7.30, tibia IV: 9.60; tibia I l/d 24.00.

Variation: Apophysis of the epigynum on one female more curved than the other. Tibia I: 13.25, 13.75.

Natural History. The specimens were collected manually on their irregular sheet webs on walls along roadcuts, in wet and shaded areas covered by roots and leaf-litter, within oak-pine forest.

Distribution. MEXICO: Oaxaca ( Fig. 146 ).

Figures

FIGURE 146. Known distribution of Ixchela mixe new species, Ixchela huberi new species, Ixchela juarezi new species, Ixchela grix new species and Ixchela taxco new species.

FIGURES 122 – 133. Ixchela grix new species. Male: 122, Habitus, lateral view. 123, Carapace, dorsal view. 124, Chelicerae, frontal view. 125, Chelicera, lateral view. 126, Carapace, frontal view. 127, Bulb and procursus, dorsal view. 128 – 129, Left palp, retrolateral and prolateral views respectively. Female: 130, Epigynum, frontal view. 131, Epigynum, ventral view. 132, Epigynum, dorsal view. 133, Epigynum, left lateral view. Scales: 1 mm (Figs 122, 123, 126 – 129), 0.5 mm (Figs 124, 125, 130 – 133).