Ixchela zapatai, Valdez-Mondragón, 2020

Valdez-Mondragón, Alejandro, 2020, COI mtDNA barcoding and morphology for species delimitation in the spider genus Ixchela Huber (Araneae: Pholcidae), with the description of two new species from Mexico, Zootaxa 4747 (1), pp. 54-76 : 54-76

Ixchela zapatai sp. nov.

Figures 14‒24

http://zoobank.org/ 3D2B8ED6-F808-453F-AC58-2619FF77BAFD

Type material. MEXICO: Oaxaca: 1 ♂ holotype (T-01393) , 1 ♀ paratype (T-01394), [13.ix.2010; A. Valdez, O. Francke, J. Cruz, D. Barrales Cols.] from 2 km NE of Guadalupe Hidalgo (17.35134°, -97.62971°, 2399 m), Federal Highway 125 N Tlaxiaco, Municipality Tlaxiaco (day collecting) . Paratypes: 2 ♂♂, 6 ♀♀, 4 immatures (T-01395), same data as holotype

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Etymology. This species is dedicated to Emiliano Zapata Salazar, better known as “Emiliano Zapata, el Caudillo del Sur”, a famous Mexican revolutionary who fought during the Mexican Revolution (1910-1917) in the Central-South region of Mexico.

Diagnosis. Closely related with I. taxco ( Figs 1 , 2 ), however in I. zapatai sp. nov. the FAC are wide and rounded in lateral view ( Fig. 18 ), whereas in I. taxco are conical and curved ( Valdez-Mondragón 2013: figs 136–138). The male palp femur in I. taxco has a ventral conical projection ( Valdez-Mondragón 2013: arrow, fig. 140), whereas in I. zapatai sp. nov. this conical projection is absent ( Figs 19, 20 ). The PAB of the male palp is wider on I. zapatai sp. nov. ( Fig. 19 ), whereas on I. taxco is smaller ( Valdez-Mondragón 2013: fig. 141). In lateral view, the female epigynum on I. zapatai sp. nov. has a conical apophysis, which is straight, large, and sharp apically ( Fig. 24 ), whereas on I. taxco the epigynum is conical ( Valdez-Mondragón 2013: fig. 145). In ventral view, the epigynum is larger in I. zapatai ( Fig. 21 ), whereas in I. taxco is smaller and with a white region next to epigastric region ( Valdez-Mondragón 2013: fig. 143); in frontal view, the epigynum in I. zapatai sp. nov. is triangular ( Fig. 23 ), whereas in I. taxco is pentagonal ( Valdez-Mondragón 2013: fig. 142).

Description. Male (Holotype). Prosoma: carapace pale yellow, with lateral spots arc-shaped ( Fig. 15 ). Ocular region brown, with wide brown line from ALE to fovea, and with a small brown triangular line behind PME ( Fig. 15 ). Fovea with an irregular and wide light brown mark around ( Fig. 15 ). Clypeus light brown ( Fig. 16 ). Chelicerae light brown, pale yellow in prolateral part, FAC small and rounded, without SAC ( Figs 16, 17 ). Sternum pale orange; labium brown, pale distally. Endites brown, paler basally, white apically. Legs: coxae pale orange, darker in prolateral and retrolateral parts. Trochanters pale brown, Femora pale orange, without rings. Patellae pale brown. Tibia, metatarsi and tarsi pale orange. Opisthosoma: conical, larger than high, pale blue coloration ( Figs 14, 15 ). Plate of genital gonopore square, gray color. Palp: femur conical, slightly curved, with VAF ( Fig. 20 ). Procursus, long, slightly sigmoid, with VPP with long setae; curved spine distally arc-shaped ( Figs 19, 20 ). Tibia with two trichobothria, one dorsally in the middle and one distally on retrolateral part. Embolus wide and long, with spine dorso-distally and curved projection ventro-apically ( Figs 19, 20 ). Measurements: total length 7.80. Carapace 3.00 long, 2.75 wide. Clypeus 1.10 long. Diameter AME 0.12, ALE 0.27, PME 0.20, PLE 0.26. Distance ALE-PME 0.20, PME-PME 0.29. Leg I: 45.00 (12.10+1.30+12.10+14.30+5.20), tibia II: 8.70, tibia III: 6.80, tibia IV: 9.10. Tibia I l/d: 22.00.

Female (T-0139). Similar to the male, differences: Prosoma: carapace with lateral spots arc-shaped darker brown. Irregular and wide brown mark around the fovea darker. Clypeus darker brown. Chelicerae dark brown, without apophyses. Sternum, labium and endites darker brown. Legs: Coxae paler orange. Trochanters and femora darker brown. Patellae brown. Tibia, metatarsi and tarsi brown. Opisthosoma: paler blue coloration. Epigynum : wider than long, with a conical and straight apophysis ( Figs 23, 24 ). PP wide, with MSE strongly sclerotized ( Fig. 22 ). Oval concavities between MSE and PP long, sac-shaped ( Fig. 22 ). Measurements: total length 9.00. Carapace 3.17 long, 3.20 wide. Clypeus 1.25 long. Diameter AME 0.13, ALE 0.28, PME 0.17, PLE 0.22. Distance ALE–PME 0.23. PME–PME 0.35. Leg I: 45.80 (11.90 + 1.40 + 12.60 + 14.50 + 5.40), tibia II: 9.00, tibia III: 7.00, tibia IV: 9.00; tibia I l/d 28.00.

Variation. The coloration is different between males and females, the females have darker coloration in body and legs than males. There is variation in the opisthosoma coloration, some specimens have opisthosoma pale blue coloration, others darker blue. Males (N = 3): tibia I: 12.10–13.00 (x = 12.46). Females (N=6): tibia I: 8.00–12.60 (x = 10.51).

Natural History. The specimens were collected on their sheet webs in a temperate pine-oak forest at 2399 m, inside cavities on walls along road-cuts in wet and shaded areas covered with roots ( Figs 27, 28 ). This is a typical microhabitat of several species of Ixchela ( Valdez-Mondragón 2013, Valdez-Mondragón & Francke 2015).

Distribution. MEXICO: Oaxaca ( Fig. 31 ).

Figures

FIGURE 1. Neighbour-Joining (NJ) with p-distances tree constructed with COI barcode sequences from different specimens and species of Ixchela. Colors in the branches indicate species, red branches + blue circles indicate the new species. Male cheliceral, male palps, and female epigyna are showed for each species to show morphological structures taxonomically important at species level. Number on branches represent Bootstrap support values (>50% significant).

FIGURE 2. Maximum Likelihood gene tree (highest log: -3749.87), constructed with COI barcode sequences of Ixchela. Colors in the branches indicate species; same colors are in the bars, which represent the different species delimitation methods used for their validation. Red branches + blue circles indicate the new species. Numbers below the bars represent the species recovered in each species delimitation method (not considering the outgroup: P. dugesi): 1: morphology (M). 2: neighbor-joining (NJ). 3: GMYC. 4: ABGD with recursive partitions (RP). 5: ABGD with initial partitions (IP). 6: bPTP with IB. 7: bPTP with ML. Numbers above branches are Bootstrap support values (>50% significant), number below are posterior probabilities (PP) support values under BI.

FIGURE 31. Type localities of Ixchela panchovillai sp. nov. (green circle) and Ixchela zapatai sp. nov. (red circle), in the state of Oaxaca, Mexico.

FIGURES 14–20. Ixchela zapatai sp. nov. Male: 14–15, Habitus, lateral and dorsal views, respectively. 16, Carapace and chelicerae, frontal view. 17, Chelicerae, frontal view. 18, Chelicerae, lateral view. 19–20, Left palp, prolateral and retrolateral views, respectively. FAC, frontal apophysis of chelicerae, PAB: prolateroventral apophysis of bulb, VPP, ventrobasal protuberance of procursus. Scale bars: 0.5 mm (Fig. 17, 18), 1 mm (Figs 16, 19, 20), 2 mm (Figs 14, 15).

FIGURES 21–24. Ixchela zapatai sp. nov. Female epigynum: 21, ventral view. 22, dorsal view. 23, frontal view. 24, lateral view. MSE: median septum of epigynum, PP: pore plates. Scale bars: 0.5 mm.

FIGURES 25–30. 25–28, Living specimens (females) of Ixchela zapatai sp. nov. from type locality. 29–30, Temperate pine-oak forest at 2399 m.a.s.l. at the type locality (red arrow indicates the microhabitat where the specimens of I. zapatai sp. nov were collected).