Séminaire Ecobio - Luis Fernando Garcia Hernandez (Universidad de la Republica, Uruguay) - Observatoire Des Sciences De L'Environnement De Rennes (OSERen)

Spider and scorpions are known for possessing a potent venom which might be harmful for humans and has attributed a negative reputation to these groups. Because of their medical relevance, most studies have focused on analyzing the venom composition while ecological and evolutionary aspects remain unexplored for the majority of species. Herein I present the relationship between venom and prey capture using as a model spiders and scorpions species. In spiders, the toxicity against different prey types was evaluated and compared using as model the species Phoneutria depilata (Formerly Phoneutria boliviensis), where prey consumption and toxicity were evaluated against vertebrate (lizards) and other arthropods (spiders) prey. We found a similar paralysis time for both prey but a higher toxicity against lizards. These results suggest that toxicity on P. depilata, against humans, might be a consequence of vertebrate consumption, just like it has been suggested for other groups such as Latrodectus spiders. In the case of scorpions a similar trend was evaluated, in the scorpions, comparing the toxicity against different insects in the scorpion Tityus fuhrmanni, showing that the toxicity in this species varies depending on the type of prey and in consequence venom dosification can vary too.