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Environmental Factors Influencing Amphibian Community Assemblage In Dune Wetlands On The Lake Michigan Coast, Alex H. Jouney
Environmental Factors Influencing Amphibian Community Assemblage In Dune Wetlands On The Lake Michigan Coast, Alex H. Jouney
Masters Theses
Wetlands in dune landscapes provide important breeding habitat for amphibians along the Lake Michigan Coast. Unfortunately, these unique habitats and the corresponding amphibian metapopulations are understudied and threatened. We assessed amphibian species richness and terrestrial habitat type in 16 permanent and ephemeral wetlands along the coast of Lake Michigan in Grand Haven, MI. Wetland area, terrestrial habitat type, depth, hydroperiod, shade, and degree of isolation were measured from April to September of 2017. Nine species of amphibian were found; Green Frog (Rana clamitans melanota) and Spring Peepers (Pseudacris crucifer crucifer) were most abundant and Fowlers Toad …
Chemotaxis Of Batrachochytrium Dendrobatidis Zoospores In Response To Live Amphibians, David Bartholow
Chemotaxis Of Batrachochytrium Dendrobatidis Zoospores In Response To Live Amphibians, David Bartholow
Masters Theses
Batrachochytrium dendrobatidis (Bd) is one of the primary drivers of amphibian decline, and has spread rapidly on a global scale, but the mechanisms of Bd movement on small spatial scales are poorly understood and may play a role in transmission and infection. The flagellated zoospores of this fungus exhibit chemotaxis in response to single chemical cues, towards potential nutrient sources and away from metabolites of anti-fungal bacteria (AFB) present on amphibian skin. Levels of cutaneous AFB were manipulated on Eurycea bislineata hosts (either by bathing in a culture of the AFB Janthinobacterium lividum, or bathing in antibiotics) …
Sequestered Alkaloid Defenses In The Dendrobatid Poison Frog Oophaga Pumilio Provide Variable Protection From Microbial Pathogens, Kyle Hovey
Masters Theses
Amphibians produce the majority of their defensive chemicals, however alkaloid defenses in poison frogs are sequestered from dietary arthropods. Alkaloids function as a defense against predators, and certain types appear to inhibit microbial growth. However, alkaloid defenses vary considerably among populations of poison frogs, reflecting geographic differences in availability of dietary arthropods. Consequently, environmentally driven differences in poison frog alkaloid defenses may have significant implications regarding their protection against pathogens. While natural alkaloid mixtures in poison frogs have recently been shown to inhibit growth of non-pathogenic microbes, no studies have examined the effectiveness of alkaloids against microbes that infect frogs. …
Seasonality, Variation In Species Prevalence, And Localized Disease For Ranavirus In Cades Cove (Great Smoky Mountains National Park) Amphibians, Megan Todd-Thompson
Seasonality, Variation In Species Prevalence, And Localized Disease For Ranavirus In Cades Cove (Great Smoky Mountains National Park) Amphibians, Megan Todd-Thompson
Masters Theses
World-wide amphibian declines sparked concern and encouraged investigation into potential causes beginning in the 1980’s. Infectious disease has been identified as one of the major potential contributors to amphibian declines. For example, Ranavirus has caused amphibian die-offs throughout the United States. Investigators isolated Ranavirus from dead or moribund amphibians during large-scale die-offs of amphibians in the Cades Cove area of Great Smoky Mountains National Park in 1999-2001. In 2009, after nearly a decade without follow-up monitoring, I undertook an investigation to determine if the virus persisted in the area, and if so, to assess spatial, temporal, and taxonomic patterns in …