Ixchela HUBER, 2000

Valdez-Mondragón, Alejandro & Francke, Oscar F., 2015, Phylogeny of the spider genus Ixchela Huber, 2000 (Araneae: Pholcidae) based on morphological and molecular evidence (CO 1 and 16 S), with a hypothesized diversification in the Pleistocene, Zoological Journal of the Linnean Society 175 (1), pp. 20-58 : 25

Ixchela HUBER, 2000

Type species: Ixchela furcula (F. O. Pickard-Cambridge, 1902) by original designation ( Huber, 2000). Type locality: 1 female holotype from Tecpam in the Región de Los Altos (Tecpam, Departamento Chimaltenango), Guatemala, around 2300 m, Godman & Salvin Cols., in BMNH (F. O. Pickard-Cambridge, 1902; Huber, 1998a) (not examined).

Diagnosis: Species of this genus can be distinguished from members of other pholcid genera by the frontal apophysis on chelicerae on males ( FAC) ( Figs 26 , 40 , 51 ); the prolateroventral apophysis of the palp bulb of the male ( PAB) ( Figs 1 , 39 , 50 ); the apical–dorsal spine-shaped projection on the embolus ( Figs 2 , 38 , 49 ); the apical–ventral projection on the embolus ( Figs 2 , 38 , 49 ); the curved spine distally on procursus ( Figs 38 , 49 , 60 ); the ventral protuberance with long setae on the procursus ( VPP) ( Figs 15 , 38 , 49 ); the procursus conical, straight and long, wide basally ( Figs 60 , 72 ); and the small, sub-distal, sclerotized spine on the embolus ( Figs 9 , 39 , 50 ).

Description: The description made by Valdez-Mondragón (2013) is currently still valid, although new morphological information has been found using scanning electron microscopy ( SEM). Embolus conical ( Fig. 1 ), with elongate, sigmoid apical ventral projection ( Figs 2, 4, 6 ), and apical dorsal projection spine-shaped ( Fig. 2 ). Sperm operculum with a small spine (arrow, Fig. 3 ). Embolus with small, spine-shaped projections prolaterally (e.g. I. azteca , arrow Figs 4, 5 ; and I. mendozai , arrow Figs 7–9 ). Embolus with subdistal, sclerotized spine (arrow, Fig. 9 ). Female palp with long and wide seta next to the tarsal organ (arrow, Fig. 13 ). Bulb rounded and wide ( Fig. 1 ). Tarsal organs exposed on palps (arrows, Figs 16, 17 ) and legs (arrow, Figs 24, 25 ). Trichobothria present on palp tibia of males and females ( Figs 10–12 ). Lyriform organs present on leg patellae (arrow, Figs 18, 19 ). Legs with 6–9 longitudinal rows of erect setae, spread around circumference of segments ( Figs 20, 21 ), without spines or curved setae. Tarsus IV with comb-setae ( Figs 22, 23 ). Male chelicerae with SAC well developed in some species (e.g. I. azteca , I. mendozai ) ( Figs 26, 27 ), vestigial in others (e.g. I. simoni , I. tzotzil ) ( Valdez-Mondragón, 2013; figs 74, 162); or absent (e.g. I. furcula , I. huberi ) ( Valdez-Mondragón, 2013; figs 34, 100). Endites with serrated margin (arrow, Figs 29, 30 ). Anterior lateral spinnerets with one small spigot and one wide spigot (arrows, Fig. 32 ). Posterior median spinnerets with two acciniform gland spigots (arrows, Fig. 33 ).

Distribution and natural history: New data on the natural history were obtained and are explained, although the general distribution and natural history of the genus given by Valdez-Mondragón (2013) is still the same. The genus Ixchela Huber, 2000 is widely distributed from north-eastern Mexico to Nicaragua [specimens not examined, but Huber (2000) examined one male of an undescribed species from Nicaragua, Matagalpa, Fuente Pura, deposited in Museo Entomológico Nicaraguense] ( Valdez-Mondragón, 2013). The genus has a natural distribution in temperate climate zones, particularly pine, oak or mixed pine–oak forest (1000–2950 m elevation) ( Valdez-Mondragón, 2013; figs 13–15, 17, 18); however, some species were collected in tropical rain forest, such as Ixchela santibanezi Valdez-Mondragón, 2013 at 1190 m ( Valdez-Mondragón, 2013; fig. 16), or in a thorny scrub forest at 1900–2180 m, such as Ixchela juarezi Valdez-Mondragón, 2013 . Most species have been collected among fallen logs, boulders on the ground, under dried leaves of agave plants and frequently on walls along road-cuts, specifically in dark, moist areas covered with roots and leaf-litter ( Valdez-Mondragón, 2013; figs 15, 17, 18), or inside caves ( Valdez-Mondragón, 2013; figs 1–3, 5, 9). However, here three synanthropic records for the genus are reported for the first time: two records of Ixchela azteca and one record of Ixchela mendozai found inside buildings.

Composition: The genus Ixchela is composed of 20 species: Ixchela simoni (O. Pickard-Cambridge, 1898) , Ixchela furcula (F. O. Pickard-Cambridge, 1902) , Ixchela abernathyi ( Gertsch, 1971) , Ixchela pecki ( Gertsch, 1971) , Ixchela placida ( Gertsch, 1971) , Ixchela franckei Valdez-Mondragón, 2013 , Ixchela grix Valdez-Mondragón, 2013 , Ixchela huasteca Valdez-Mondragón, 2013 , Ixchela huberi Valdez-Mondragón, 2013 , Ixchela juarezi Valdez-Mondragón, 2013 , Ixchela mixe Valdez-Mondragón, 2013 , Ixchela santibanezi Valdez-Mondragón, 2013 , Ixchela taxco Valdez- Mondragón, 2013, Ixchela tzotzil Valdez-Mondragón, 2013 , Ixchela viquezi Valdez-Mondragón, 2013 , Ixchela azteca sp. nov., Ixchela jalisco sp. nov., Ixchela mendozai sp. nov., Ixchela purepecha sp. nov. and Ixchela tlayuda sp. nov.

The identification key of species of Ixchela Huber, 2000 is updated from Valdez-Mondragón (2013 – hereafter VM, 2013), using the same abbreviations.

Figures

Figures 26–33. Ixchela azteca sp. nov. Male. 26, Chelicerae, ventral view. 27, Left chelicerae, frontal view. 28, Right chelicerae, posterior view. 29, Left endite, ventral view (arrow indicates the serrated margin). 30, Detail of the serrated margin on endite. 31, Spinnerets, ventral view. 32, Detail of one anterior lateral spinneret (arrows indicate the slightly pointed spigot and the wide spigot). 33, Detail of one posterior median spinneret (arrows indicate the acciniform gland spigots). Scale bars: 50 μm (Figs 30, 32, 33), 100 μm (Figs 28, 29), 200 μm (Fig. 27), 300 μm (Fig. 31), 500 μm (Fig. 26).

Figures 34–44. Ixchela azteca sp. nov. Male: 34, 35, Habitus, lateral and dorsal views, respectively. 36, Carapace and chelicerae, frontal view. 37, Chelicerae, frontal view. 38, 39, Left palp, retrolateral and prolateral views, respectively. 40, Chelicera, lateral view. Female: 41, Epigynum, left lateral view. 42, Epigynum, ventral view. 43, Epigynum, dorsal view. 44, Epigynum, frontal view. Scale bars: 0.5 mm (Figs 42, 43), 1 mm (Figs 34–41, 44).

Figures 45–55. Ixchela jalisco sp. nov. Male: 45, 46, Habitus, lateral and dorsal views, respectively. 47, Carapace and chelicerae, frontal view. 48, Chelicerae, frontal view. 49, 50, Left palp, retrolateral and prolateral views, respectively. 51, Chelicera, lateral view. Female: 52, Epigynum, left lateral view. 53, Epigynum, ventral view. 54, Epigynum, dorsal view. 55, Epigynum, frontal view. Scale bars: 0.5 mm (Figs 48, 51, 52, 54, 55), 1 mm (Figs 45–47, 49, 50, 53).

Figures 1–9. Ixchela azteca sp. nov. (1–6) and Ixchela mendozai sp. nov. (7–9). 1, Left palp showing bulb, PAB and embolus, prolateral view. 2, 3, Embolus, prolateral–dorsal view (arrow indicates the spine on sperm duct). 4, 6, Embolus, prolateral and retrolateral views, respectively (arrow indicates the spine-shaped projections). 5, 7, Details of the spineshaped projections on embolus. 8, Embolus, distal view (arrow indicates the spine-shaped projections). 9, Embolus, retrolateral view (arrow indicates the sub-distal, sclerotized spine). Scale bars: 30 μm (Fig. 7), 50 μm (Fig. 5), 100 μm (Figs 3, 8, 9), 200 μm (Figs 2, 4, 6), 500 μm (Fig. 1).

Figures 56–67. Ixchela mendozai sp. nov. Male: 56, 57, Habitus, lateral and dorsal views, respectively. 58, Carapace and chelicerae, frontal view. 59, Chelicerae, frontal view. 60, 61, Left palp, retrolateral and prolateral views, respectively. 62, Chelicera, lateral view. 63, Bulb and embolus, prolatero-dorsal view (arrow indicates the curved and sharp subdistally sclerotized spine). Female: 64, Epigynum, ventral view. 65, Epigynum, dorsal view. 66, Epigynum, left lateral view. 67, Epigynum, frontal view. Scale bars: 0.5 mm (Figs 58, 59, 62–67), 1 mm (Figs 56, 57, 60, 61).

Figures 10–17. Ixchela jalisco sp. nov. (10–14, 17) and Ixchela mendozai sp. nov. (15, 16). 10, Trichobothria of the tibia, male palp. 11, Trichobothria socket, detail. 12, Female left palp, showing trichobothria on tibia. 13, Female left palp (arrow indicates the setae on tarsus). 14, Male palp, detail of basal setae on dorsal area of procursus. 15, Setae on ventrobasal protuberance of procursus. 16, Procursus basal part (arrow indicates the exposed tarsal organ). 17, Female left palp (arrow indicates the tarsal organ). Scale bars: 50 μm (Fig. 11), 100 μm (Figs 15, 17), 200 μm (Figs 10, 14), 300 μm (Figs 13, 16), 500 μm (Fig. 12).

Figures 68–78. Ixchela purepecha sp. nov. Male: 68, 69, Habitus, lateral and dorsal views, respectively. 70, Carapace and chelicerae, frontal view. 71, Chelicerae, frontal view. 72, 73, Left palp, retrolateral and prolateral views, respectively. 74, Chelicera, lateral view. Female: 75, Epigynum, left lateral view. 76, Epigynum, ventral view. 77, Epigynum, anterior–dorsal view. 78, Epigynum, frontal view. Scale bars: 0.5 mm (Figs 71, 74, 75, 77), 1 mm (Figs 68, 69, 72, 73, 76, 78).

Figures 18–25. Ixchela azteca sp. nov. Male. 18, Left patella IV, ventral view (arrow indicates the lyriform organs). 19, Left patella IV, detail of the lyriform organs. 20, Left tibia IV, basal part, ventral view. 21, Tibia IV, detail of the setae. 22, Left tarsus IV, retrolateral view (arrows indicate the comb-hairs). 23, Left tarsus IV, detail of the median claw and comb-hairs. 24, Left tarsus IV, detail of the pseudosegments (arrow indicates the tarsal organ). 25, Left tarsus IV, detail of the tarsal organ and setae socket. Scale bars: 30 μm (Figs 23, 25), 50 μm (Figs 19, 22), 100 μm (Fig. 24), 300 μm (Fig. 21), 400 μm (Fig. 18), 500 μm (Fig. 20).