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

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  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...

Neurotoxicity of Sri Lankan Krait (Bungarus ceylonicus) and Common Krait (Bungarus caeruleus) Venoms and Their Neutralisation by Commercial Antivenoms In Vitro

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Neurotoxicity of Sri Lankan Krait (Bungarus ceylonicus) and Common Krait (Bungarus caeruleus) Venoms and Their Neutralisation by Commercial Antivenoms In Vitro

Abstract

The common krait (Bungarus caeruleus) and the endemic Sri Lankan krait (B. ceylonicus) are two species of krait responsible for envenomings in Sri Lanka that result in progressive neuromuscular paralysis. We characterised the in vitro neurotoxicity of B. ceylonicus and B. caeruleus venoms and studied their neutralisation by two commercially available Indian polyvalent antivenoms (i.e., VINS and BHARAT), Thai banded krait antivenom and Australian polyvalent antivenom using the chick biventer cervicis nerve-muscle preparation. Both venoms displayed concentration-dependent neurotoxicity, showing equipotent pre-synaptic neurotoxicity at 0.03 μg/mL. At a higher concentration (1 μg/mL), both venoms showed post-synaptic neurotoxicity, with B. ceylonicus venom being more potent. VINS was unable to neutralise the neurotoxicity of B. ceylonicus venom, but neutralised both pre- and post-synaptic neurotoxicity of B. caeruleus venom. BHARAT neutralised in vitro pre- and post-synaptic activity of both B. ceylonicus and B. caeruleus venoms. Banded krait antivenom and Australian polyvalent antivenoms were unable to fully neutralise the neurotoxicity of either venom at tested concentrations. In conclusion, B. ceylonicus venom shows pre- and post-synaptic neurotoxicity similar to B. caeruleus venom. BHARAT effectively neutralises both pre- and post-synaptic neurotoxicity of B. ceylonicus venom. Both Indian polyvalent antivenoms effectively neutralise neurotoxicity induced by B. caeruleus venom.

Galappaththige, J., Isbister, G. K., Maduwage, K., Hodgson, W. C., & Silva, A. (2025). Neurotoxicity of Sri Lankan Krait (Bungarus ceylonicus) and Common Krait (Bungarus caeruleus) Venoms and Their Neutralisation by Commercial Antivenoms In Vitro. Toxins, 17(9), 439. https://doi.org/10.3390/toxins17090439