Pholcophora tehuacan Huber sp. nov.

urn:lsid:zoobank.org:act: D7F69EC5-F4AB-4425-AABF-3257B146EA8A

Figs 3J–K, 25–29, 33K–L

Diagnosis

Easily distinguished from most known congeners (except P. maria Gertsch, 1977) by small size (carapace width <0.70; tibia 1 length <1.0) and by pair of tube-like sacs in female internal genitalia (Fig. 28B). From P. maria by shorter female internal sacs (60 µm vs 110 µm), smaller body (total body length 1.2 vs 1.65; carapace width 0.55 vs 0.65) and shorter legs (female tibia 1: 0.60–0.65 vs 0.93). Male of P. maria unknown.

Remark

Judging from the female internal genitalia (compare Fig. 28B with Huber 2000: fig. 1357), this species may be closely related to P. maria Gertsch, 1977 which is known from a single female specimen originating from Yucatan, Cueva (Gruta, Actún) Xpukil (20.551° N, 89.912° W, 80 m a.s.l.). This implies that P. maria is probably correctly placed in Pholcophora (it was considered incertae sedis in Huber 2000).

Etymology

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

Type material

Holotype MEXICO – Puebla • ♂; ~ 35 km SE of Tehuacan, Calapa bridge, N side; 18.1652° N, 97.2605° W; 1020 m a.s.l.; 24 Oct. 2019; B.A. Huber and A. Valdez-Mondragón leg.; LATLAX.

Paratypes MEXICO – Puebla • 2 ♂♂, 1 ♀, and 1 female abdomen; same collection data as for holotype; ZFMK Ar 23949 • 4 ♂♂, 22 ♀♀; same collection data as for holotype; LATLAX • 1 ♂, 1 ♀; same collection data as for holotype but W side of Calapa bridge; 18.1619° N, 97.2647° W; 1010 m a.s.l.; 23 Oct. 2019; ZFMK Ar 23950 .

Other material examined

MEXICO – Puebla • 2 ♂♂, 6 ♀♀, 5 juvs, in pure ethanol; same collection data as for holotype; four female prosomata used for molecular work, 1 ♂ 1 ♀ used for SEM, 1 female abdomen transferred to ZFMK Ar 23949; ZFMK Mex353 • 1 ♂, 1 ♀; same collection data as for holotype; partly used for µ-CT study; ZFMK • 1 ♂; same collection data as for holotype; partly used for karyotype analysis; ZFMK 23951 • 1 juv., in pure ethanol; same collection data as for holotype but W side of Calapa bridge; ZFMK Mex350 .

Description

Male (holotype)

MEASUREMENTS. Total body length 1.20, carapace width 0.55. Distance PME-PME 40 µm; diameter PME 45 µm; distance PME-ALE 20 µm; distance AME-AME 15 µm; diameter AME 20 µm. Leg 1: 2.55 (0.75 + 0.20 + 0.65 + 0.60 + 0.35), tibia 2: 0.55, tibia 3: 0.50, tibia 4: 0.75; tibia 1 L/d: 8; diameters of leg femora 0.11–0.12, of leg tibiae 0.08.

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

BODY. Habitus as in Fig. 3J. Ocular area barely raised. Carapace with low thoracic groove. Clypeus unmodified, very short (clypeus rim to ALE 0.12). Sternum slightly wider than long (0.34/0.32), almost round (i.e., not heart-shaped), with pair of small but distinct anterior processes (~30 µm long) near coxae 1. Abdomen globular; gonopore with four epiandrous spigots (Fig. 29C); ALS with seven spigots, PMS with two spigots (Fig. 29G).

CHELICERAE (Fig. 26A–B). With pair of frontal apophyses directed downwards; stridulatory ridges very fine (Fig. 29A; distances between ridges 2.0–2.2 µm), not visible in dissecting microscope.

PALPS (Fig. 25). Coxa unmodified; trochanter without process; femur proximally with retrolateral-ventral process and prolateral stridulatory pick, distally widened but simple, slightly curved towards dorsal; femur-patella joints slightly shifted toward prolateral side; tibia very short, with two trichobothria; tibia-tarsus joints not shifted to one side; tarsal organ raised, with small opening (Fig. 29E); procursus very simple (Fig. 26C–E), with subdistal constriction and semi-transparent tip; genital bulb complex (Fig. 26F–H), with distinctive retrolateral-dorsal apophysis and long distal process.

LEGS. Without spines and curved hairs; with usual low number of short vertical hairs; retrolateral trichobothrium of tibia 1 at 60%; prolateral trichobothrium absent on tibia 1; tarsus 1 with 6 pseudosegments, all fairly distinct.

Variation (male)

Tibia 1 in ten males (incl. holotype): 0.60–0.65 (mean 0.62).

Female

In general, similar to male (Fig. 3K) but sternum without pair of anterior humps, and chelicerae without stridulatory files (Fig. 29B). Total body length ~1.20–1.40; tibia 1 in 14 females 0.60–0.65 (mean 0.62). Epigynum (Fig. 27) with short and simple anterior plate slightly protruding in lateral view; posterior plate wide, median part not separated from lateral parts by pair of whitish anterior areas. Internal genitalia (Fig. 28) with pair of distinct sacs (receptacles?) 60 µm long, without (or with very small?) pore plates.

Distribution

Known from type locality only, in Mexico, Puebla (Fig. 2).

Natural history

The spiders were found by turning rocks in a very dry area (Fig. 34D). They shared the microhabitat and sometimes the individual rock with a small undescribed species of Physocyclus Simon, 1893, and were difficult to distinguish from juveniles of that species. At disturbance they started to run rapidly and dropped from the rock to the ground (where they could no longer be found). The area was shared by a second representative of Pholcophora (“Mex354”, see below), which also shared the microhabitat but was never found on the same rock as Pholcophora tehuacan sp. nov.