The Effects of Predaceous Diving Beetle Larvae Removal on Size and Abundance of California Tiger Salamander

Students: Abigail Doan, Savannah Kellerman, Jesse Schmieg

Faculty Mentor: Derek Girman

Biology

College of Science, Technology, and Business

Vernal pools are seasonal wetland ecosystems that are home to a variety of plant and animal specialist species. Habitat loss has resulted in these specialists becoming threatened or endangered, including the California Tiger Salamander (Ambystoma californiense), which spends its larval stage as a vernal pool predator. In order to properly curate management plans of threatened ecosystems, an understanding of trophic interactions among predators in these ecosystems is vital. In the current study, the impacts of the predaceous diving beetle larvae (Family Dytiscidae), a predator of A. californiense larvae, on the abundance and size of A. californiense are observed via the removal of Dytiscid larvae from multiple experimental sites. Two vernal pools that are known to contain larvae of both A. californiense and Dytiscidae were divided into a control and experimental side using mesh screening, and Dytiscid larvae were removed from the experimental side via timed dipnet surveys. Timed dipnet surveys were also used to monitor A. californiense larvae on both sides and record their relative abundance as well as their body length and gape size. Regular timed dipnetting is performed throughout the season to monitor these factors and routinely remove Dytiscidae from the experimental side.