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

Posted by
  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 , ...

First record of Tropicosa thorelli (Araneae: Lycosidae) attacking the dragonfly Rhionaeschna marchali (Odonata: Aeshnidae)

Posted by

 


First record of Tropicosa thorelli (Araneae: Lycosidae) attacking the dragonfly Rhionaeschna marchali (Odonata: Aeshnidae)

Abstract 

This study records thirteen predation attempts by the wolf spider Tropicosa thorelli (Keyserling) on males of the aeshnid dragonfly Rhionaeschna marchali (Rambur) in a protected area of the Colombian Andes. All events occurred on macrophyte vegetation near the shoreline of the Tominé Reservoir, at the locality of Club Náutico El Muña. For each event, we recorded perch height, time of occurrence, attack duration, and ambient temperature. The observations took place between 11:01 and 11:47 h during the dry season, under temperatures ranging from 21.2 to 23.7 °C. The mean duration of attack events was 12.72 ± 2.41 min. In all cases, the attacks were interrupted by the arrival of R. marchali males, although the mechanisms underlying this behavior remain unclear. These observations suggest that perch characteristics, particularly perch height, may influence the vulnerability of R. marchali males to predation by sit-and-wait spiders. 

Palacino Rodríguez, F., & Palacino-Penagos, D. A. (2026). Primer registro de Tropicosa thorelli (Araneae: Lycosidae) atacando a la libélula Rhionaeschna marchali (Odonata: Aeshnidae). Biota Colombiana, 27, e1300. https://doi.org/10.21068/2539200X.1300