Ixchela mixe, 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 : 304-306

Ixchela mixe new species

Figures 86–97

Type data. MEXICO: Oaxaca: 1 3 holotype (CNAN T0399) [15 March 2008; A. Valdez, H. Montaño, C. Santibañez] from Cueva de Tlahuitoltepec (lat 17.0929°, lon -96.0547°; 2032 m), Municipio Santa María Tlahuitoltepec, Distrito Mixes; inside the cave. Paratypes: 1 Ƥ, 3 immatures (CNAN T0400) [20 July 2007; A. Valdez, O. Francke, H. Montaño, C. Santibáñez, A. Ballesteros], same locality as holotype. 1 3, 2 ƤƤ (one with egg sac) (CNAN T0623 and T0624) [14 September 2009; A. Valdez, C. Santibáñez, R. Paredes], same locality as holotype.

Etymology. The specific name is a noun in apposition and refers to the ethnic group of the region of Oaxaca where the type locality is located: Los Mixes.

Diagnosis. Resembles to I. pecki , distinguished by the FAC conical and larger, distally with SAC shorter and directed towards prolateral part of chelicerae ( Figs 88–90 ); by palp femur without VAF ( Figs 91, 92 ); by the distal sclerotized spine on the embolus, small and flat distally (arrows Figs 91, 92 ); by epigynum larger than wide, being wider in middle part ( Figs 95, 96 ); and by VAE conical and shorter, separated from each other, located above anterior rounded protuberance ( Figs 94, 95, 97 ).

Description. Male (Holotype). Prosoma: Carapace pale brown, with two anterior pale regions, next to ocular region ( Fig. 87 ). Carapace with three thin pale gray lines, inconspicuous, extending from fovea to lateral margins ( Fig. 87 ). Ocular region brown, with a thin, dark brown U-shaped region in posterior part ( Fig. 87 ). Clypeus pale yellow, with wide brown region ( Fig. 90 ). Chelicerae dark brown, distally pale ( Fig. 88 ). Sternum pale olive green, darker anteriorly. Labium dark green, pale distally. Endites basally orange, olive green in middle part and pale distally. Legs: Coxae pale orange. Trochanters orange. Femora brown, dark on legs I and II, pale on legs III and IV. Patellae and tibiae pale brown. Metatarsi and tarsi orange. Opisthosoma: Pale blue, globular, higher than long ( Fig. 86 ). Palp: Femur conical ( Figs 91, 92 ). Procursus short, VPP inconspicuous and with long setae ( Fig. 91 ). Procursus with distal spine thin and small ( Figs 91–93 ). Embolus short, with long spine dorsal-apical ( Figs 91, 92 ). Measurements: Total length 5.15. Carapace 2.25 long, 2.10 wide. Clypeus length 0.80. Diameter AME 0.09, ALE 0.20, PME 0.14, PLE 0.17. Distance ALE-PME 0.10, PME-PME 0.25. Leg I: 46.30 (12.40+0.90+12.20+16.50+4.30), tibia II: 8.70, tibia III: 7.10, tibia IV: 8.60. tibia I l/d 32.33.

Female (Paratype). (CNAN T0624). Similar to the male, differences: Legs: Femora brown, dark in basal part. Patellae, tibiae, metatarsi and tarsi pale brown. Epigynum: Larger than wide, brown on anterior and posterior parts, olive green in central part ( Figs 94, 95 ). VAE anterior, short, conical ( Figs 94, 95, 97 ). PP short, on posterior part of epigynum , with oval concavities sac-shaped between MSE and PP ( Fig. 96 ). MSE short and wide, T-shaped ( Fig. 96 ). Measurements: Total length 4.70. Carapace 2.00 long, 1.90 wide. Clypeus 0.75 long. Diameter of AME 0.06, ALE 0.18, PME 0.13, PLE 0.14. Distance ALE-PME 0.08, PME-PME 0.20. Leg I: 38.86 (10.38+0.83+10.00+ 13.75+3.90), tibia II: 7.40, tibia III: 6.10, tibia IV: 7.35; tibia I l/d 33.33.

Variation: There is variation in the shape of VAE, two females with VAE apically asymmetric; on another female VAE smaller, where even one of the two VAE in this is smaller than the other. Male tibia I: 12.20, 12.75. Female tibia I: 10.00–10.87 (x = 10.54).

Natural History. The spiders were collected inside the cave, on their sheet webs on walls, near the ground, and between boulders ( Fig. 5 ). This cave was exceptionally small, with 20 m of total length, and located in a disturbed pine forest. The cave had low humidity, ca 50%, and also showed evidence of human disturbance inside.

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 86 – 97. Ixchela mixe new species. Male: 86, Habitus, lateral view. 87, Carapace, dorsal view. 88, Chelicerae, frontal view. 89, Chelicera, lateral view. 90, Carapace, frontal view. 91 – 92, Left palp, retrolateral and prolateral views respectively (arrows indicate the distal sclerotized spine on the embolus, small and flat distally). 93, Bulb and procursus, dorsal view. Female: 94, Epigynum, frontal view. 95, Epigynum, ventral view. 96, Epigynum, dorsal view. 97, Epigynum, left lateral view. Scales: 1 mm (86, 87, 90 – 92), 0.5 mm (88, 89, 93, 94 – 97).

FIGURES 1 – 12. Living specimens of the genus Ixchela Huber, 2000, from Mexico. 1, Ixchela abernathyi (Gertsch, 1971), female from Km 227 Carretera Federal No. 70 Cd. San Luis Potosí-Rio Verde, San Luis Potosí. 2, Ixchela placida (Gertsch, 1971), female from Cueva de Atlahuilapa, Veracruz. 3, Ixchela pecki (Gertsch, 1971), female from Cueva de Teopisca, Chiapas. 4, Ixchela simoni (O. Pickard-Cambridge, 1898) from 2 km W of crossroad Omiltemi-Chautipan, Guerrero. 5, Ixchela mixe new species, female with egg sac from cave near Tlahuitoltepec, Oaxaca. 6, Ixchela huberi new species, male from Santa Inés del Monte, Oaxaca. 7, Ixchela juarezi new species, female with egg sac from 2 km E of Guelatao, Oaxaca. 8, Ixchela taxco new species, female from Rancho La Soñadora, 6 km W of Taxco, Guerrero. 9, Ixchela franckei new species, male from Cueva del Borrego, 3.5 km E of Omiltemi, Guerrero. 10 – 11, Ixchela huasteca new species: 10, male from 1.5 km road to Microondas La Pingüica, Querétaro; 11, female with egg sac from Buenavista, near Ahuacatlan, San Luis Potosí. 12, Ixchela tzotzil new species, male from Grutas de Arcotete, Chiapas.