Pisaboa marcuzzii Huber & Villarreal 2020, comb. nov.
Creators: name: Huber, Bernhard A.
name: Villarreal, Osvaldo
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Pisaboa
Pisaboa marcuzzii

description: Pisaboa marcuzzii (Caporiacco, 1955) comb. nov.
Figs 773–774, 779–784, 787–789, 1024, 1063
Psilochorus marcuzzii Caporiacco, 1955: 299, figs 9a–b (♂♂).
Diagnosis
Easily distinguished from most known congeners (except P. retracta Huber sp. nov.) by male chelicerae (Figs 781–782; apophyses in proximal rather than distal position, not hinged) and by shape of epigynal plate (Fig. 787; wider anteriorly than posteriorly); from P. retracta Huber sp. nov. by shape of procursus (strongly curved, i.e., S-shaped; compare Figs 783 and 785), by smooth epigynal plate (compare Figs 788, 791), by internal female genitalia smaller relative to epigynal plate (compare Figs 789, 792), and by weakly annulated legs (each femur with only one subdistal dark ring versus three dark rings in P. retracta Huber sp. nov.; compare Figs 773–774 and 775–776). From all known congeners also distinguished by thickened male leg femur 2 (in large males only).
Type material
VENEZUELA – Falcón • ♂ holotype, supposedly in Museo de Biología, Universidad Central de Venezuela, Caracas (# 563) (see Notes below), Santa Ana [approximately 11.78° N, 69.95° W], Sep. 1948 (G. Marcuzzi); not examined.
New records
VENEZUELA – Falcón • 7 ♂♂, 4 ♀♀, ZFMK (Ar 22077), and 2 ♂♂, 2 ♀♀, 1 juv. in pure ethanol, ZFMK (Ven18-186), Península de Paraguaná, Cerro Santa Ana (11.8177° N, 69.9468° W), 480 m a.s.l., 17 Nov. 2018 (B.A. Huber, O. Villarreal M.) • 1 ♀, MIZA 105802 (MAGS 749), Dtto. Acosta, Agua Salada, El Pozón [approximately 10.98° N, 68.71° W], 3 Oct. 1981 (A.R. Delgado de G., J.A. González D., M.A. González S.) • 5 ♂♂, 2 ♀♀, ZFMK (Ar 22078), and 3 ♀♀ in pure ethanol, ZFMK (Ven20-145, 152), forest near Santa Cruz de La Alegría (10.8795° N, 68.4949° W), 100 m a.s.l., 15 Feb. 2020 (B.A. Huber, O. Villarreal M., Q. Arias C.).
Notes
There are several “Santa Ana” in Falcón, including the state capital Coro which is officially “Santa Ana de Coro”. However, according to Marcuzzi (1954; text and maps), he collected on the Península de Paraguaná, suggesting that the type locality is at approximately 11.78° N, 69.95° W.
The holotype could not be found at the Museo de Biología, Universidad Central de Venezuela but it remains unclear if it is lost or on loan (Edmundo Guerrero, pers. comm.). Nevertheless, the specimens below appear very likely conspecific with the holotype for three reasons: (1) the new series from Cerro Santa Ana is from very close to the type locality (probably less than 5 km); (2) The shape of the procursus (Fig. 783) is fairly identical to Caporiacco’s (1955) figure 9a. (3) The specimens below share the distinctively thickened male femur 2 with the holotype in the original description (femora “II valde incrassata”).
Description
Male (ZFMK, Ar 22077)
MEASUREMENTS. Total body length 2.0, carapace width 0.95. Distance PME–PME 60 µm; diameter PME 90 µm; distance PME–ALE 40 µm; distance AME–AME 10 µm; diameter AME 30 µm. Leg 1: 15.2 (3.7 +0.4 +3.9+6.1 +1.1), tibia 2: 2.5, tibia 3: 1.9, tibia 4: 2.3; tibia 1 L/d: 49; femur 1–4 maximum diameter: 0.22, 0.28, 0.25, 0.23.
COLOR (in ethanol). Carapace pale ochre-yellow, with light brown lateral marginal bands and median band including ocular area; clypeus also light brown; sternum light brown, anteriorly whitish; legs ochre-yellow to light brown, with indistinct dark rings subdistally on femora; abdomen pale bluish, with darker bluish internal marks, ventrally with large light brown plate in front of gonopore.
BODY. Habitus as in Fig. 773. Ocular area moderately raised. Carapace with distinct thoracic groove. Clypeus unmodified. Sternum wider than long (0.66/0.50), with pair of low humps frontally. Abdomen globular.
CHELICERAE. As in Figs 781–782, with pair of proximal apophyses that do not appear articulated.
PALPS. As in Figs 779–780, almost indistinguishable from those of P. silvae Huber, 2000 and P. estrecha Huber, 2000 (cf. Huber 2000: figs 1133–1137); coxa with large rounded retrolateral apophysis, trochanter barely modified, femur proximally with retrolateral process, distally widening, with fingershaped retrolateral-ventral process; procursus very simple, S-shaped (Fig. 783); genital bulb with mostly membranous processes distally tapering, with pointed process on prolateral side (arrow in Fig. 779).
LEGS. Without spines and curved hairs; with vertical hairs in high density on all tibiae; retrolateral trichobothrium of tibia 1 at 11%; prolateral trichobothrium absent on tibia 1; tarsus 1 with ~20 pseudosegments, distally fairly distinct.
Male (variation)
Tibia 1 in 13 males: 3.2–4.1 (mean 3.7). Second and third femora variably thickened, sometimes barely thicker than other femora (e.g., male with tibia 1 length 3.2: 0.18, 0.19, 0.18, 0.17), sometimes much thicker (e.g., male with tibia 1 length 3.8: 0.24, 0.35, 0.28, 0.22). Some males with indistinct dark rings also on tibiae (proximally and subdistally). Dark median band on carapace variably wide and variably distinct.
Female
In general similar to male (Fig. 774) but all femora of approximately same diameter, sternum without humps, dark rings on legs slightly more distinct, vertical hairs on tibiae in barely higher than usual density. Tibia 1 in 11 females: 2.5–3.0 (mean 2.8). Epigynum (Fig. 787) large trapezoidal light brown plate, anteriorly wider than posteriorly, weakly protruding, smooth, with pair of shallow pockets at anterior margin, greenish internal arc distinct in uncleared specimens; with short but wide posterior plate; without whitish humps in front of epigynum. Internal genitalia (Figs 784, 788–789), very small relative to epigynal plate, pore plates in lateral vertical position, with membranous oval receptacle between internal genitalia and epigynal plate.
Distribution
Known from three localities in the Venezuelan state Falcón (Fig. 1063).
Natural history
At Cerro Santa Ana, the spiders were collected in a humid part of the forest where the small webs were built in the leaf litter, often at the basis of ground-dwelling bromeliads (Fig. 1024). In the well preserved forest fragment near Santa Cruz de La Alegría the spiders occupied the same microhabitat, but their small webs (diameter ~ 10 cm) were only found in an area where the leaves appeared particularly dry.
description: Published as part of Huber, Bernhard A. & Villarreal, Osvaldo, 2020, On Venezuelan pholcid spiders (Araneae, Pholcidae), pp. 1-317 in European Journal of Taxonomy 718 on pages 220-224, DOI: 10.5852/ejt.2020.718.1101, http://zenodo.org/record/4069574