Ixchela panchovillai, 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 panchovillai sp. nov.

Figures 3‒13

http://zoobank.org/ 0F8BA7AD-317B-4591-9F70-03E6B86B16A0

Type material. MEXICO: Oaxaca: 1 ♂ holotype (T-01390) , 1 ♀ paratype (T-01391) [30.iv.2014; J. Mendoza, J. Cruz, S. Davlantes, M. Minkton Cols.] from Cueva Li Nita (18.14767°, -96.79844°, 1919 m), Municipality Huautla de Jiménez (day collecting inside the cave). Paratypes : 3 ♂♂, 3 ♀♀, 1 immature (T-01392), same data as holotype .

Etymology. This species is dedicated to Doroteo Arango Arámbula, better known as “Francisco Villa”, “Pancho Villa”, or “Centauro del Norte”; a famous Mexican revolutionary who fought during the Mexican Revolution (1910- 1917) in the North of Mexico.

Diagnosis. Closely related with I. placida ( Fig. 1 ), however morphologically in I. panchovillai sp. nov. the FAC of the male are absent ( Figs 3–5 ), whereas in I. placida the FAC are conical and long ( Valdez-Mondragón, 2013: figs 62–64). The pale regions around the SAC are slightly smaller on I. panchovillai sp. nov. ( Fig. 6 ), whereas in I. placida are larger ( Valdez-Mondragón, 2013: fig. 62). The male palp femur is slightly thinner and longer in I. panchovillai sp. nov. ( Figs 8, 9 ) than in I. placida ( Valdez-Mondragón, 2013: figs 65, 66). PAB is wide and conical in I. panchovillai sp. nov. ( Fig. 8 ), whereas in I. placida is thinner, slightly curved and finger-shaped ( Valdez-Mondragón, 2013: fig. 66). The procursus of I. panchovillai sp. nov. is long and straight ( Fig. 9 ), whereas in I. placida is slightly sigmoid ( Valdez-Mondragón, 2013: fig. 65). In ventral view, female epigynum of I. panchovillai sp. nov. is pentagonal ( Fig. 10 ), in frontal view, with two lateral prominent corners ( Fig. 12 ), and in lateral view, with an anterior small projection ( Fig. 13 ). In I. placida female epigynum in ventral view is oval ( Valdez-Mondragón, 2013: fig. 66), in frontal view with two lateral corners more prominent than the new species ( Valdez-Mondragón, 2013: fig. 68), and in lateral view square-shaped, without anterior small projection ( Valdez-Mondragón, 2013: fig. 71).

Description. Male (Holotype). Prosoma: carapace pale orange, with brown spots on each side ( Fig. 4 ). Ocular region brown, with small pale areas behind PLE, brown and trapezoidal-shaped region around fovea ( Fig. 4 ). Clypeus brown ( Fig. 5 ). Chelicerae dark brown, paler on small region basally; with sclerotized and curved small SAC in distal third part of chelicerae ( Fig. 6 ). Sternum orange, brown around; labium brown, pale distally. Endites dark brown, pale distally, orange basally. Legs: coxae pale orange, brown distally on prolateral and retrolateral parts. Trochanters brown. Femora dark brown, without rings, orange basally and distally. Patellae pale brown. Tibia pale brown, without rings, paler distally. Metatarsi dark brown, orange basally, tarsi dark brown. Opisthosoma: globular, higher than large, pale blue ( Figs 1 , 2 ). Plate of genital gonopore square, gray. Palp: femur with VAF ( Figs 8, 9 ). Procursus long, VPP with long setae; curved spine distally ( Fig. 9 ). Tibia with two long setae dorsodistally and 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 ( Fig. 8 ). Measurements: total length 9.50. Carapace 3.80 long, 3.60 wide. Clypeus 1.35 long. Diameter AME 0.16, ALE 0.31, PME 0.25, PLE 0.30. Distance ALE-PME 0.28, PME-PME 0.28. Leg I: 80.00 (20.50+1.60+19.60+29.10+9.20), tibia II: 15.40, tibia III: 12.40, tibia IV: 15.00. Tibia I l/d: 33.16.

Female (T-01391). Similar to the male, differences: Prosoma: carapace with brown spots on each side darker than male. Fovea with darker brown mark around. Clypeus darker brown. Chelicerae without apophyses. Sternum, labium and endites darker brown. Epigynum : longer than wide ( Figs 10, 13 ). PP wide, with MSE sclerotized ( Fig. 11 ). Oval concavities between MSE and PP sac-shaped ( Fig. 11 ). Measurements: total length 9.00. Carapace 3.60 long, 3.50 wide. Clypeus 1.50 long. Diameter AME 0.18, ALE 0.36, PME 0.25, PLE 0.28. Distance ALE–PME 0.18. PME–PME 0.31. Leg I: 76.20 (19.10 + 1.70 + 19.20 + 27.20 + 9.00), tibia II: 14.30, tibia III: 11.40, tibia IV: missing; tibia I l/d 32.00.

Variation. The coloration is very similar between males and females; however, legs in males are slightly darker brown than females. There is variation in the opisthosoma coloration, some specimens have opisthosoma pale grey, others darker grey. Males (N = 4): tibia I: 18.20–19.60 (x = 19.05). Females (N=3): tibia I: 18.10–19.20 (x = 18.63).

Natural History. The cave where the spiders were collected is located in a large karstic zone, in pine forest at ~ 1900 m elevation. The spiders were collected inside a karstic cave about 25 m from the entrance. They were hanging from irregular sheet webs from walls and among boulders and other karstic formations. The cave had high humidity, (ca. 80%), and was fairly cold.

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 3–9. Ixchela panchovillai sp. nov. Male: 3–4, Habitus, lateral and dorsal views, respectively. 5, Carapace and chelicerae, frontal view. 6, Chelicerae, frontal view. 7, Chelicerae, lateral view. 8–9, Left palp, prolateral and retrolateral views, respectively. PAB: prolateroventral apophysis of bulb, SAC: sclerotized apophysis of chelicerae, VAF: ventrodistal apophysis of femur, VPP, ventrobasal protuberance of procursus. Scale bars: 0.5 mm (Figs 6, 7), 1 mm (Figs 5, 8, 9), 2 mm (Figs 3, 4).

FIGURES 10–13. Ixchela panchovillai sp. nov. Female epigynum: 10, ventral view. 11, dorsal view. 12, frontal view. 13, lateral view. MSE: median septum of epigynum, PP: pore plates. Scale bars: 0.5 mm (Figs 12, 13), 1 mm (Figs 10, 11).