Tolteca oaxaca Huber & Meng & Valdez-Mondragón & Král & Ávila Herrera & Carvalho 2023, sp. nov.

Tolteca oaxaca Huber sp. nov.

urn:lsid:zoobank.org:act: 85F8D1C1-9EC5-407C-A507-90D0270F18A9

Figs 36K–L, 50–54, 55G–H

Pholcophora hesperia Gertsch, 1982: 102 (specimens from Oaxaca only; see Remarks under T. hesperia).

Tolteca hesperia – Huber 2000: 118 (part; see Remarks under T. hesperia), figs 75, 126, 448–453, 455–457 (not fig. 454).

Diagnosis

Distinguished from known congeners by the combination of: male genital bulb without dorsal ridge (unlike T. jalisco); procursus tip gradually narrowing (Fig. 51C; unlike T. hesperia and T. sinnombre sp. nov.); male cheliceral apophyses close together (Fig. 51A; distance between tips ~40 µm, i.e., closer together than in T. manzanillo sp. nov. and T. sinnombre), in lateral view very small and with small angle against distal-frontal face of chelicera (Fig. 51B; unlike T. hesperia; not checked in T. jalisco); main epigynal plate crescent-shaped (Fig. 52A, C; rather than band-like as in T. hesperia and T. jalisco); sacs in female internal genitalia tiny, only ~9–13 µm long (Fig. 55G–H; smaller than in all known congeners).

Etymology

The species name is derived from the type locality; noun in apposition.

Type material

Holotype MEXICO – Oaxaca • ♂; ~ 3 km N of San Pedro Totolapa; 16.6976° N, 96.3180° W; 1100 m a.s.l.; 26 Oct. 2019; B.A. Huber and A. Valdez-Mondragón leg.; LATLAX.

Paratypes MEXICO – Oaxaca • 4 ♂♂; same collection data as for holotype; ZFMK Ar 23961.

Other material examined

MEXICO – Oaxaca • 19 ♀♀, in pure ethanol; same collection data as for holotype; four prosomata used for molecular work, two females used for SEM, two cleared abdomens transferred to ZFMK Ar 23961; ZFMK Mex 362 • 3 ♂♂; same collection data as for holotype; partly used for karyotype analyses; ZFMK 23962 • 3 ♂♂, 3 ♀♀; same collection data as for holotype; partly used for µ-CT study; ZFMK 23963 • 2 ♂♂, 2 ♀♀ abdomens; ~ 17 km NW of Tehuantepec; 16.3919° N, 95.3865° W; 165 m a.s.l.; 27 Oct. 2019; B.A. Huber and A. Valdez-Mondragón leg.; ZFMK Ar 23964 • 4 ♀♀, 4 juvs, in pure ethanol; same collection data as for preceding; two female abdomens transferred to ZFMK Ar 23964; ZFMK Mex 368 • 2 ♂♂; same collection data as for preceding; partly used for karyotype analyses; ZFMK 23965 • 2 ♂♂, 3 ♀♀; same collection data as for preceding; partly used for µ-CT study; ZFMK 23966 • 2 ♂♂, 11 ♀♀, 2 juvs (subadult males); same collection data as for preceding; LATLAX.

Description

Male (holotype)

MEASUREMENTS. Total body length 1.13, carapace width 0.47. Distance PME-PME 45 µm; diameter PME 45 µm; distance PME-ALE 15 µm; distance AME-AME 10 µm; diameter AME 30 µm. Leg 1: 2.07 (0.55 + 0.17 + 0.52 + 0.53 + 0.30), tibia 2: 0.42, tibia 3: 0.38, tibia 4: 0.65; tibia 1 L/d: 9; diameters of leg femora 0.11, of leg tibiae 0.06.

COLOUR (in ethanol). Prosoma and legs monochromous ochre-yellow; abdomen slightly darker ochre-grey, also monochromous.

BODY (Fig. 36K). Ocular area barely raised. Carapace without thoracic groove. Clypeus unmodified, short (clypeus rim to ALE: 130 µm). Sternum wider than long (0.35/0.30), almost round (i.e., not heart-shaped), with pair of small but distinct anterior processes (~50 µm diameter at basis, ~50 µm long) near coxae 1. Abdomen globular.

CHELICERAE (Fig. 51A–B). With pair of frontal apophyses pointing downwards, distance between tips of apophyses: 50 µm; without stridulatory files.

PALPS (Fig. 50). Coxa unmodified; trochanter without process; femur proximally without process, distally widened but simple, slightly curved towards dorsal; femur-patella joints not (or barely) shifted to one side; tibia very short, with two trichobothria; tibia-tarsus joints not shifted to one side; procursus very simple (Fig. 51C), with distal ventral process; genital bulb as in Fig. 51D–F, in light microscope possibly indistinguishable from congeners.

LEGS. Without spines and curved hairs; with slightly increased density of short vertical hairs on tibia 1 (barely visible in dissecting microscope); retrolateral trichobothrium of tibia 1 at 59%; prolateral trichobothrium absent on tibia 1; tarsus 1 with six pseudosegments, all fairly distinct.

Variation (male)

Tibia 1 in seven newly collected males (incl. holotype): 0.48–0.58 (mean 0.53).

Female

In general, similar to male (Fig. 36L) but sternum without pair of anterior humps, tibia 1 without increased density of short vertical hairs. Total body length: ~1.20; tibia 1 in 21 newly collected females: 0.47–0.56 (mean 0.51). Epigynum (Figs 52, 54A) short crescent-shaped anterior plate slightly protruding in lateral view; posterior plate short and wide, very indistinct, barely visible. With distinct knob between epigynum and pedicel (Fig. 54B). Internal genitalia (Fig. 53) with pair of strong transversal sclerites, with very short sacs (Fig. 55G–H), without (or with very small?) pore plates.

Distribution

Apparently widely distributed in the state of Oaxaca, Mexico (Fig. 35). We have not restudied Gertsch’s (1982) and Huber’s (2000) specimens but consider all their records of Pholcophora / Tolteca hesperia from Oaxaca to represent this species.

Natural history

At the type locality, a dry hill with a sparse and low tree cover (Fig. 56C), the spiders were found in high densities in the thin layer of leaf litter and among small pebbles on the ground (Fig. 56D). Within ~1.5 h, ~30 individuals were seen within an area of ~ 4 m 2. In slightly more humid (shaded) areas on the same hill, two other species of Pholcidae were found (Modisimus sp.; Physocyclus paredesi Valdez-Mondragón, 2010). At the second locality, a slightly higher and denser roadside forest, Tolteca was also collected at a rather dry spot with a thin layer of leaf litter, while more humid areas contained other Pholcidae genera (Modisimus sp.; Physocyclus paredesi; Anopsicus sp.; Psilochorus sp.).