The distribution, spatial clustering, and density of trapdoor spiders in two California coastal dune ecosystems

Posted by
  The distribution, spatial clustering, and density of trapdoor spiders in two California coastal dune ecosystems Abstract Coastal dune ecosystems support endemic trapdoor spiders, yet population data for these species are limited. We conducted the first coastal dune trapdoor spider population estimation surveys at Moss Landing State Beach (California) and for Aptostichus stephencolberti Bond 2008 at Sunset State Beach using randomly selected 1m 2 quadrats across ~26,000 m 2 per site. Burrow densities were similar between sites (Sunset: 0.287 burrows/m 2 ; Moss: 0.453 burrows/m 2 ), yielding estimated population sizes of ~35,206 and ~30,959 individuals, respectively. However, spatial analyses revealed contrasting patterns of burrow distribution. At Sunset State Beach, burrow presence was strongly associated with vegetation and occurred closer to plants, despite vegetation being randomly distributed. In contrast, no vegetation–burrow association was detected at Moss Landing, alth...

The venom of Cyriopagopus schmidti spider contains a natural huwentoxin-IV analogue with unexpected improved analgesic potential

Posted by

The venom of Cyriopagopus schmidti spider contains a natural huwentoxin-IV analogue with unexpected improved analgesic potential

The venom of Cyriopagopus schmidti spider has been extensively investigated, thereby allowing the identification of numerous new natural peptides. Many of these peptides are active on ion channels and several of them occur from post-translational processing. In order to further identify new entities, we screened this venom against five different human voltage-gated sodium (hNav) channels. We illustrate the unusual richness of this venom in targeting this wide variety of hNav channels. We confirm the identity of previously discovered peptides active on these ion channels type (huwentoxin (HwTx)-I, HwTx-II and HwTx-IV), indicating the efficacy of the screening process by automated patch-clamp. We also identified a novel analogue of HwTx-IV that differs by the absence of amidation and the presence of an extra C-terminal Gly residue. Interestingly, this analogue is less potent than HwTx-IV itself in blocking hNav1.7 in cell lines, but turns out to be significantly more potent in TTX-sensitive dorsal root ganglia neurons. Because of this unexpected finding, this novel analogue turns out to be a more potent analgesic than HwTx-IV itself without presenting most of the Nav1.6-related toxic effects of HwTx-IV.

Antunes, A., Montnach, J., Khakh, K., Lopez, L., Thomas, B., Jaquillard, L., Servent, D., Béroud, R., Cohen, C. J., Benoit, E., & De Waard, M. (2025). The venom of Cyriopagopus schmidti spider contains a natural huwentoxin-IV analogue with unexpected improved analgesic potential. Frontiers in Pharmacology, 16, 1566312. https://doi.org/10.3389/fphar.2025.1566312