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    P1: ASIH Storer Award Herpetology

    2021-07-26   16:00 - 18:00

    To view the posters go to You will be able to chat one-on-one during the Monday poster session, the e-poster platform.

    1.  16:00  Survey of Ranavirus Across Southeastern South Dakota. Danielle Galvin*, University of South Dakota; Jacob Kerby, University of South Dakota

    Amphibians in the Midwestern United States face a variety of threats including habitat loss, pollution, and diseases. These threats contribute to declining amphibian populations locally and globally. Pathogens, particularly the iridovirus Ranavirus (Rv), are of great interest to South Dakota conservation. Previous sampling efforts have detected Rv just across the Missouri River in Nebraska’s Cedar and Dixon counties. During summer of 2020 we constructed a survey to determine if Rv is present in southeastern South Dakota. Sampling efforts included ventral and cloacal swabbing, toe clipping, and the collection of deceased specimens for liver tissue analysis. We utilized the non-invasive swabbing technique to sample state threatened and endangered species and toe clipping technique was used for the highly abundant species. All samples were analyzed using quantitative polymerase chain reaction (qPCR) to determine Rv presence and viral load. From these analyses we determined that ranavirus was detected at several of the South Dakota sampling locations for several different species. We will highlight patterns in the survey and outline a large-scale follow up study is being conducted in summer of 2021 to investigate the impacts of Rv presence and to determine Rv prevalence across the state. Additionally, continued work will expand to monitor for the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal).

    3.  16:00  Top Predators Drive Community Structure of Tadpole Assemblages. Tatiana Joaqui*, Stephen F. Austin State University; Daniel Saenz, U.S. Forest Service; Cory Adams, U.S. Forest Service; Toby Hibbitts, Texas A&M University; Christopher Schalk, Stephen F. Austin State University

    Both biotic and abiotic factors underlie the assembly of ecological communities. Predator-prey interactions (biotic factors) affect prey morphology, behavior, and ultimately, persistence in local habitats, which in turn, can affect community structure and function. In this study, we explored the effect of top predators on anuran diversity patterns in permanent ponds in Texas. We surveyed larval anuran assemblages across four top predator regimes including: 1) Largemouth Bass (LB) (Micropterus salmoides) only, 2) Green sunfish (GS) (Lepomis cyanellus) only, 3) a combination of both LB and GS, and 4) salamander/invertebrate predators (SI). LB and GS, are considered the dominant top predators in aquatic communities in this region, which affect tadpole communities by feeding directly on tadpoles (i.e. GS, SI) or by feeding directly on tadpole predators (i.e. LB). Fish sampling was conducted in 2007 and anuran sampling was conducted across two years (2008 -2009). Fish sampling was conducted using hook and line and dipnetting while anuran tadpoles and SI was done using dipnetting. In total, 11 species of anuran larvae were collected across the 45 ponds sampled. Ponds, where GS was the top predator, contained the fewest tadpole species (mean= 2.7 species) compared to ponds with both LB+GS (mean = 3.6 species), ponds with LB only (mean = 5.8 species), and in ponds with SI as top predators (mean = 6.09 species). We show that different top predator identity has different effects on anuran tadpole communities which is likely mediated through both direct and indirect effects.

    4.  16:00  Morph- and sex-specific differences in corticosterone of the Arizona tiger salamander (Ambystoma mavortium nebulosum). Megan Zerger*, Murray State University; Kelsey Reider, James Madison University; Andrea Darracq, Murray State University; Howard Whiteman, Murray State University

    Life history morph, sex, and body condition are traits that may influence stress within salamander populations because of differences in physiology and environmental conditions. Given widespread declines and the effects chronic stress can have on amphibian health, it is important to understand within-population drivers of stress and how population level variation may influence population viability. Thus, the objective of our study was to assess how corticosterone varies within the Arizona tiger salamander (Ambystoma mavortium nebulosum) population at the Mexican Cut Nature Preserve, Colorado. We used a non-invasive skin swabbing method to collect baseline and elevated corticosterone from paedomorph (aquatic morph; N = 30 male,14 female) and metamorph (terrestrial morph; N = 10 male, 22 female) Arizona tiger salamanders in July 2020. Baseline samples were collected within three minutes of capture. We then induced stress via manual restraint, and collected elevated stress samples at 0, 30, 60, 90, and 120 minutes post-restraint. Preliminary results suggest baseline corticosterone ranges from 797 to 2,297 pg/mL (mean±SE = 1547 ± 275 pg/mL). The timing of peak corticosterone levels varied across individuals and occurred at 30, 60, and 90 min. Additional samples will be processed soon, and will allow us to consider variability in corticosterone by sex, body condition, and morph. Our study will provide a better understanding of how stress hormones can be used to assess population health and disease susceptibility. Future research utilizing this method could clarify the effects of climatic variation and population density in amphibian populations.

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