Anthony Waddle

Assisted staff scientists with qualitative analysis of a variety of environmental samples. Performed data entry, equipment maintenance, and literature surveys. Utilized scanning electron microscopy (SEM), field flow fractionation (FFF), and single particle-inductively coupled plasma mass spectrometry (SP-ICPMS), to characterize nanoparticles in suspension.

Presented at the Joint Meeting of Icthyologists and Herpetologists in Austin, Texas (July 2017) Abstract: Chytridiomycosis is an emerging infectious disease of amphibians caused by the aquatic fungal pathogen, Batrachochytrium dendrobatidis (Bd). This pathogen has spread to every continent where amphibians occur, and has been linked to hundreds of species declines and many well-documented extinctions. Prior research into the thermal tolerance of Bd suggested that this invasive fungus may not be a threat in hot, arid regions. Recent contradictory evidence, however, prompted us to investigate the occurrence and impact of Bd in a frog species of conservation concern in the Mojave Desert. The relict leopard frog was historically more widespread, but now only exists naturally in thermal springs in two general areas in southern Nevada where high water temperatures may provide refuge from Bd. We sampled and detected Bd within the historical range of the relict leopard frog and in one population of the species. We subsequently performed Bd exposure studies to determine the susceptibility of this frog to chytridiomycosis. Our early efforts, using Bd strains isolated during die-offs of other anuran species in California, suggested that the pathogen might not be a substantial threat to the relict leopard frog. Our more recent efforts, however, show that Bd isolated from southern Nevada, including an isolate from a relict leopard frog, and Bd isolated from captive exotic amphibians increased mortality in the species. Our future research will borrow from the creativity of other Bd researchers in an effort to provide solutions to the management challenges for the relict leopard frog