Metagonia mariguitarensis ( González-Sponga, 1998 )

Huber, Bernhard A. & Meng, Guanliang, 2025, New species of Metagonia Simon with directionally asymmetric male and female genitalia (Araneae, Pholcidae), European Journal of Taxonomy 1026, pp. 199-235 : 203-206

Metagonia mariguitarensis ( González-Sponga, 1998)

Figs 1A – B, 2A – B, 3 – 7

Anomalaia mariguitarensis González-Sponga, 1998: 25 , figs 21 – 32 (fig. 28 missing).

Metagonia mariguitarensis – Huber 2000: 67, figs 256 – 263 (except specimens from Peru, figs 264 – 267, see Distribution below); 2004: 318, figs 15 – 28. — Carvalho et al. 2017: 13. — Huber & Villarreal 2020: 179, figs 640 – 643, 1052 (except specimens from Falcón, see Distribution below). — Huber et al. 2022: 678 (molecular data, except specimen M092 Metagonia mariguitarensis Ven 20-149, see Metagonia wayuu sp. nov. below).

Notes

This species has been studied extensively (see synonymy) and we do not have new material. However, it is included here because two very similar species newly described below require an updated diagnosis, and because a few details were missing in previous studies. In addition, some specimens previously assigned tentatively to this species are now considered to belong to other species (see Distribution below).

Diagnosis

Leaf-dwelling, long-legged pholcid with dark pattern on carapace ( Figs 1 – 2). Easily distinguished from most known congeners (except M. wayuu sp. nov. and M. uca sp. nov.) by strongly asymmetric male palps ( Figs 3 – 4; including asymmetry of femur and tibia), by male chelicerae with pair of strong lateral protrusions ( Fig. 5A), and by female external and internal genitalia ( Figs 5C, 6 – 7; epigynum with posterior semicircular process, or ‘scape’; internal genitalia with complex system of pouches, ducts, and folds). Distinguished from both M. wayuu and M. uca by male chelicerae with rounded rather than pointed distal apophyses ( Fig. 5A), by main branch of left procursus with distinctive ventral indentation (bold arrow in Fig. 4C), by hair-like process on right procursus (arrow in Fig. 4D), and by less pronounced palpal asymmetry, i.e., absolutely and relatively smaller right palp (e.g., right/left tibia diameter <2.5 vs> 2.6; see also Fig. 22). Further distinguished from M. uca by different color pattern on carapace (both in males and females; Fig. 2), by smaller size and shorter legs (e.g., male tibia 1 <5.0 vs> 6.5; female tibia 1<4.0 vs> 5.5), and by female external genitalia (epigynal scape without asymmetric groove; compare Fig. 6B with Fig. 16B).

Description (amendments; see Huber 2000, 2004)

Right procursus with hair-like process on retrolateral side (arrow in Fig. 4D). Prolateral trichobothrium absent on tibia 1, present on other leg tibiae. Female tibia 1 length (N = 50): 3.2 – 3.8 (mean 3.5). Shape of pore plates slightly variable ( Fig. 7B, D).

Barcodes

We sequenced five specimens from two localities (geographic distance: 270 km) ( Table 1; Fig. 23). Within localities, distances were 0.0%; between localities, distances ranged from 8.4 – 9.1% ( Table 2). Distances to the other three species treated herein ranged from 15.5 to 20.2 %.

Distribution

Known from several localities in eastern Venezuela ( Sucre, Bolívar) and northwestern Brazil ( Roraima) ( Fig. 24). The females from Falcón listed in Huber & Villarreal (2020) are here assigned to the newly described M. wayuu sp. nov. (see below). Specimens from Peru listed and illustrated in Huber (2000) are considered to represent a distinct, formally undescribed species (or more than one species).