Physocyclus globosus Taczanowski 1874
Creators: name: Huber, Bernhard A.
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Araneae
Pholcidae
Physocyclus
Physocyclus globosus

description: Physocyclus globosus (Taczanowski, 1874)
Physocyclus boconoensis González-Sponga, 2007: 56 –57, 67, pl 1 figs. 1–9; new synonymy. Physocyclus borburatensis González-Sponga, 2007: 58 –60, 67, pl 2 figs. 1–9; new synonymy. Physocyclus cariacoensis González-Sponga, 2007: 60 –62, 68, pl 3 figs. 1–9; new synonymy. Physocyclus guatirensis González-Sponga, 2007: 62 –64, 68, pl 4 figs. 1–10; new synonymy. Physocyclus monaguensis González-Sponga, 2007: 64 –66, 69, pl 5 figs. 1–9; new synonymy.
Justification of synonymies. Several lines of evidence strongly support the synonymies: the characters used by González- Sponga (2007) to diagnose the species, the biogeography of Physocyclus, the microhabitats of the “new” species, and genetic data of populations of P. globosus from several countries, including the type locality of P. cariacoensis in Venezuela.
Characters. As in the cases above, most of González-Sponga’s (2007) drawings, even though minimalist, clearly point at P. globosus (see drawings in Huber & Eberhard 1997, Saaristo 2001, Beatty et al. 2008). Plates 1 and 5 show all the characteristic traits of the species: the shapes of procursus and “embolar division” (embolus with attached sclerite); the small cone-shaped projections frontally on the male chelicerae; the distinctive triangular epigynum with median frontal projection. In plate 2 the distal spine on the procursus seems to be missing (or it is drawn in a too proximal position). Plate 3 is the only one in which the labium is correctly drawn. In all others, the whitish-transparent frontal part is missing and only the brown posterior part is shown. The procursus in this plate differs because it is shown is a slightly dorsal view, and in the drawing of the chelicerae the tips of the palpal endites are included. In plate 4 the bulb is rotated away from its normal position and as a result the embolar division is shown in dorsal view. All other minor differences can either be easily explained by slightly different angles of view (e.g. carapace shape and eye positions, see above) or by natural variation. For example, the conical projections on the male chelicerae vary slightly in number and position, sometimes even resulting in asymmetry (e.g. fig. 2 in Huber & Eberhard 1997).
The measurements include so many errors that they are difficult to evaluate. For example, in table 1, legs 3 are longer than legs 4 in both males and females. In all other species (and in fact in all other known pholcids) legs 4 are considerable longer than legs 3. In the same table, the ratio of carapace width/length is 2.5 while in the respective figure it is about 1.1–1.3 (depending on whether the clypeus is included or not). In table 5, the male leg 1 has the shortest femur of all legs, while in fact it should have the longest (like the female and like all other species). In general, however, the data mostly fall within the range of a Costa Rican population of P. globosus (Huber 1996). For example, male tibia 1 in that study ranged from 7.9–12.3 mm (in González-Sponga’s specimens the range is 7.7–12.3); carapace width ranged from 1.5–2.2 mm (in González-Sponga’s specimens the range is 1.5–2.0).
Biogeography. The distribution of the genus Physocyclus given by González– Sponga (2007) (West Africa, tropical Asia, North, Central, and South America, Antilles) is in fact approximately the distribution of P. globosus (which actually includes all tropical regions of the world). All other congeners are restricted to North and Central America, ranging from Costa Rica to the USA. The only exception is the dubious P. v i r i d i s Mello–Leitão from Brazil, which – judging from the original drawings (the type is lost) – “is almost certainly misplaced” (Huber 2000: 149). During an expedition to Venezuela in 2002, we found P. globosus in several places, including Mariguitar, the type locality of P. cariacoensis. As expected, we found no other species of Physocyclus.
Microhabitat. Five of González–Sponga’s (2007) “new species” where collected in human buildings. One was additionally found under rocks and between buttresses of trees in the village of Barburata. Human constructions and their surroundings are the typical habitat of P. globosus.
Genetic data. Gene sequence data of P. globosus from Venezuela (Mariguitar, the type locality of P. cariacoensis), Guatemala, and the Comoro Islands (Astrin et al. 2006) showed that they are almost identical: 16S p–distances between specimens from Venezuela and other localities ranged from 0.3–1.7%. On the other hand, distances between P. globosus populations and an unidentified Mexican species ranged from 23.7–24.0% (Astrin et al. 2006; raw data unpublished).
description: Published as part of Huber, Bernhard A., 2009, Four new generic and 14 new specific synonymies in Pholcidae, and transfer of Pholcoides Roewer to Filistatidae (Araneae), pp. 64-68 in Zootaxa 1970 on pages 66-67, DOI: 10.5281/zenodo.185015