Niche partitioning and intraspecific shared webs in two species of Modisimus Simon, 1893 (Pholcidae: Araneae)

Carballo-Morales J.D.; Delgado-Montes C.; Auccacusi-Choque L.V.; Reyes-Ortiz M.; Aisenberg A. · Journal of Arachnology (2022) · DOI: 10.1636/joa-s-21-020

Resumen

The pholcid spiders Modisimus bribri Huber, 1998 and M. guatuso Huber, 1998 construct three-dimensional webs, including sheet dome and irregular shapes, occasionally shared by males and females. We studied species spatial disaggregation and confirmed web-sharing and prey capture dominance in shared webs. We observed 22 M. bribri and 25 M. guatuso webs and recorded their height above the ground, dome dimensions, and web-sharing. In shared webs, we recorded which individual captured prey. Modisimus bribri builds webs at greater heights (~6.5 times), with larger dimensions (~2 times) than M. guatuso. In both species, neither the occupant sex nor the number of individuals on the web had a significant effect on web dimensions. We confirmed differential web location between species and did not find evidence of chivalrous dominance in prey-capture in shared webs. This study contributes to the general knowledge of three-dimensional web-building spiders, posing new questions for future research.