Differential Hematotoxic Activity of Southeast Asian Pit Viper Venoms: The Cross-Neutralizing Effect of Available Antivenoms

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  Image Credit: Creative Commons (some rights reserved) CC BY-NC Photo 111998430, (c) Nicholas Hess Differential Hematotoxic Activity of Southeast Asian Pit Viper Venoms: The Cross-Neutralizing Effect of Available Antivenoms Abstract Background/Objectives : Pit vipers (subfamily Crotalinae) are responsible for a large proportion of snakebite envenoming cases in Southeast Asia. Envenomation by these snakes commonly causes hematotoxic effects, including platelet dysfunction and coagulation disturbances. Although antivenom remains the mainstay of treatment, species-specific antivenoms are not available for several regional pit viper species. This study evaluated the hematotoxic activities of selected Southeast Asian pit viper venoms and the cross-neutralizing capacity of commercially available antivenoms.  Methods : Venoms from five medically important pit viper species— Calloselasma rhodostoma ,  Trimeresurus albolabris ,  T. hageni ,  T. purpureomaculatus , ...

Spider Web Architecture and Rainfall Damage: Observational and Manipulative Studies Along a Precipitation Gradient on the Tropical Andes

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Spider Web Architecture and Rainfall Damage: Observational and Manipulative Studies Along a Precipitation Gradient on the Tropical Andes

ABSTRACT

Rainfall is a key abiotic factor influencing species' overall fitness and their ecological interactions. Although rainfall's effects are expected to be generally positive, high-intensity rainfall can damage biological structures and thereby reduce fitness. As silk structures should be particularly vulnerable to heavy rainfall, web-building spiders can serve as ideal systems for examining the impacts of rainfall on organisms and their extended phenotypes. Here, we investigated how spider webs with different geometries—two-dimensional (2D) orbs and three-dimensional (3D) tangles and sheet-and-tangles—are affected by varying levels of rainfall intensity given both their physical structure and microhabitat use. We studied the impact of rainfall on spider webs along an elevational gradient on the eastern slopes of the Tropical Andes in Ecuador where rain intensity ranges from strong (> 4 mm/h) to mild (< 2 mm/h) from the lowland rainforests to higher-elevation cloud forests. We found that web damage significantly increased with rainfall intensity, but the amount of damage webs suffered differed for different web types. Orb webs, which are built in open microhabitats, had the highest probability of damage. Sheet-and-tangle webs, on the other hand, suffered the greatest material loss, likely due to their high silk content, despite being located in more protected microhabitats. A manipulative experiment showed that webs artificially protected from the rain suffered significantly less damage than those left unprotected, demonstrating the role of immediate cover in mitigating the impact of rainfall as a function of microhabitat use. Our findings demonstrate that spiders with different web architectures are differentially affected by heavy rainfall, thus highlighting the need to consider rainfall intensity as a factor determining the composition of web-building spider communities across precipitation gradients.

Lin, Y. H., Brescovit, A. D., & Avilés, L. (2026). Spider Web Architecture and Rainfall Damage: Observational and Manipulative Studies Along a Precipitation Gradient on the Tropical Andes. Ecology and Evolution, 16(4), e73432. https://doi.org/10.1002/ece3.73432