Preferred Session: Natural History of Amphibians Type of paper: Oral presentation Paper Title: Predator-Prey Relationships Among Top Predators in California Vernal Pools: Dynamics of California Tiger Salamanders (Ambystoma californiense) and Predaceous Diving Beetle Larvae (Family Dytiscidae) H. Jesse Schmieg, Sonoma State University, 350 Gazania Ct, Santa Rosa, CA 95405, schmiegj@sonoma.edu, (763) 250-8399; Co–authors: Dave Cook; and Derek Girman Abstract: In California vernal pools, both California Tiger Salamanders (Ambystoma californiense) and predaceous diving beetle larvae (family Dytiscidae) serve as top predators, playing key roles in shaping aquatic ecosystems. Through mesocosm experiments, we aim to investigate whether salamander larvae face higher mortality in the presence of predaceous diving beetle larvae, the predation rates between them, and how size disparities between these two predators may affect these interactions. Additionally, we seek to deepen our understanding of trophic dynamics in these ecosystems. As vernal pools continue to decline due to habitat loss and degradation, understanding these predator-prey interactions is essential for informing conservation efforts and managing the cascading effects of species interactions.