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Evaluation And Application Of Crispr-Cas12a-Based Systems For Amphibian Detection From Dietary And Environmental Dna, Macie Chess

Electronic Theses and Dissertations

Current methods for monitoring biodiversity are hindered by detection efficiencies or rely on expensive laboratory equipment. The goal of this study was to evaluate the application of a CRISPR-Cas12a-based system for the species-specific detection of amphibians from dietary and environmental DNA samples. A Cas-12a-based platform was designed and analyzed for the fluorescent detection of three salamander species; Desmognathus fuscus, D. ochropheaus, and Erycia bislineata. This system was applied to the identification of salamander DNA extracted from the fecal sacs of nestling Louisiana Waterthrush (Parkesia monticola), amplified with PCR primers targeting the CYT B mtDNA gene, and compared to DNA metabarcoding. …

Applying Conservation Genomic Techniques To Guide Management Of The Reticulated Flatwoods Salamander (Ambystoma Bishopi), Miranda Gaupp

Electronic Theses and Dissertations

The Reticulated flatwoods salamander (Ambystoma bishopi) is a federally endangered amphibian endemic to the longleaf-pine ecosystem of the southeastern U.S. This study used analyses of single-nucleotide polymorphism (SNP) data, collected from 2,255 unique individuals across 5 breeding seasons, spread across the known extant range of A. bishopi, to characterize the genetic diversity and demographics of populations, genetic relationships among populations, and patterns and spatial extents of gene flow, and to evaluate potential effects of management on A. bishopi’s resiliency. Population structure was strongly hierarchical, with individual breeding ponds (n = 38) acting as semi-connected subpopulations …

Effect Of Male Age And Hormone Induction On Sperm Quality In The Critically Endangered Mississippi Gopher Frog (Lithobates Sevosus), Ashley Michelle Watt

Electronic Theses and Dissertations

Zoos can play a key role in ex-situ conservation, focused on the management of imperiled species whose survival is dependent on conservation programs to effectively breed and reintroduce individuals back into the wild. Consequently, captive bred populations rarely become self-sustained and zoos often become limited by small, ageing populations with reproductively exhausted individuals. To overcome reproductive challenges, zoos can employ exogenous hormones to induce gamete production for artificial fertilizations. Using the critically endangered Mississippi gopher frog (Lithobates sevosus), our research focused on these two aspects of reproduction in captivity. First, we examined the effects of age on sperm quality through …

Biodiversity And Evolution In The Guiana Shield, South America, Andrew Michael Snyder

Electronic Theses and Dissertations

The neotropics are characterized as the most species rich region in the world. Unfortunately, the region's unparalleled biodiversity has not protected it from ongoing threats such as agriculture, mining, logging, oil extraction, and climate change. I studied the biodiversity and evolution of the herpetofauna of South America in order to investigate the influence of historical geological and climatological events in shaping extant neotropical diversity, particularly the Guiana shield. For my research, I set out to explore the processes involved in shaping the remarkable extant diversity using anuran amphibians as models. With my dissertation, I provide a comprehensive review of the …

Stress, Sexual Signaling, And Alternative Mating Tactics In Male Green Treefrogs, Hyla Cinerea, Sarah Crocker-Buta

Electronic Theses and Dissertations

This thesis examines how the endocrine stress response mediates the expression of courtship signals and alternative mating tactics in male green treefrogs, Hyla cinerea. Males of this species produce acoustic signals that stimulate production of the stress hormone corticosterone (CORT) in vocal competitors, suggesting a role of CORT in intrasexual competition. I predicted that modulation of CORT level during intraspecific contests plays a pivotal role in regulating the expression of male courtship signals and behavior. Consistent with this prediction, CORT administration to calling males, simulating CORT production during male vocal contests, decreased attractiveness by compromising energetic investment in vocalization, increasing …

Factors Affecting Infectivity And Pathogenicity Of Batrachochytrium Dendrobatidis In Amphibians., Forrest Michael Brem

Electronic Theses and Dissertations

Wildlife diseases are a current threat to biodiversity, and amphibians have suffered the greatest disease-induced declines and extinctions in history. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has contributed to recent pandemic population declines and extinctions of amphibians. My dissertation focused on factors that affect infectivity and pathogenicity of Bd in amphibian hosts. I demonstrated variation in critical aspects of Bd biology between Bd isolates from different climates, Panama and the USA. Panamanian Bd had larger thalli, higher overall zoospore production, and longer duration of zoospore production than Bd from the USA. I also demonstrated time-dependent rates of …

Forest Succession And Amphibian Migrations: Implications For Landscape Connectivity, Viorel Dan Popescu

Electronic Theses and Dissertations

Conservation of forest-dependent amphibians is dependent on finding a balance between timber management and species’ habitat requirements. Accurate predictions of the response of amphibian communities to disturbance rely on a good understanding of the scales at which ecological processes affect distribution and abundance through space and time. I investigated the response of 14 species to four different forestry treatments (partial harvest, clearcut with coarse woody debris [CWD] removed, clearcut with CWD retained, and uncut control) over a six-year period, using 2.1-ha experimental treatments. Forest amphibians showed a strong negative response to complete canopy removal at a broad spatial scale, but …

Amphibian Habitat Usage Of Two Restored Bogs In Shady Valley, Johnson County, Tennessee., Amy P. Lucas

Electronic Theses and Dissertations

Adjacent terrestrial habitat surrounding wetlands are critical for the survival and success of many species that use them. The primary purpose of this study was to determine amphibian movement from adjacent habitats into Orchard Bog, a restored bog located in Shady Valley, Johnson County, Tennessee. In addition, a secondary bog, Quarry Bog, was also studied determining baseline presence/absence data

A total of 16 species from six families were observed throughout the study sites. Seven species of anurans, Bufonidae, Hylidae, and Ranidae and nine species of caudates in the families Plethodontidae, Ambystomatidae and Salamandridae were identified. Fourteen of the 16 species …

The Relationship Of Herpetofaunal Community Composition To An Elephant (Loxodonta Africana) Modified Savanna Woodland Of Northern Tanzania, And Bioassays With African Elephants, Nabil A. Nasseri

Electronic Theses and Dissertations

Herpetofauna diversity and richness were compared in areas that varied in the degree of elephant impact on the woody vegetation (Acacia spp.). The study was conducted at Ndarakwai Ranch in northeastern Tanzania. Elephants moving between three National Parks in Kenya and Tanzania visit this property. From August 2007 to March 2008, we erected drift fences and pitfall traps to sample herpetofaunal community and examined species richness and diversity within the damaged areas and in an exclusion plot. I captured 143 individuals comprising 13 species of reptiles in the order Sauria and nine species of anurans. Areas of heavy damage yielded …

Limnological And Landscape Factors Affecting Use Of Manufactured Ponds By The Invasive Cuban Treefrog (Osteopilus Septentrionalis), Terina Nusinov

Electronic Theses and Dissertations

Exotic amphibians are often detrimental to native biotas. In Florida, the exotic Cuban Treefrog (Osteopilus septentrionalis) eats native frogs and may outcompete them for resources. Cuban Treefrogs thrive in disturbed areas and around buildings, and often breed in manufactured wetlands such as retention ponds and borrow pits. This study identified limnological, landscape, and biotic characteristics that discouraged pond use by Cuban Treefrogs and promoted use by native amphibian species. I sampled natural and manufactured ponds in Orange County, Florida, for one year, using standard methods to estimate the species richness and relative abundance of amphibians and their potential fish and …

Pond-Breeding Amphibian Species Distributions In A Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine, Jesse Cunningham

Electronic Theses and Dissertations

In order to maintain pond-breeding amphibian species richness, it is important to understand how both natural and anthropogenic disturbances affect species assemblages and individual species distributions both at the scale of individual ponds and at a larger landscape scale. The goal of this project was to investigate what characteristics of ponds and the surrounding wetland landscape were most effective in predicting pond-breeding species richness and the individual occurrence of wood frog (Rana sylvatica), bullfrog (Rana catesbeiana) and pickerel frog (Rana palustris) breeding sites in a beaver-modified landscape and how this landscape has changed over …

Hydroperiod Of Wetlands And Reproduction In Wood Frogs (Rana Sylvatica) And Spotted Salamanders (Ambystoma Maculatum), Mary Beth Kolozsvary

Electronic Theses and Dissertations

Many amphibians rely on wetlands for reproduction and the differential distribution of amphibian species along a gradient of wetland permanence is striking, yet not absolute. Wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum) are thought to rely on seasonal wetlands for greatest breeding success, but there is little documentation of their reliance on these or other habitats. In my first chapter, I studied these species in wetlands across a hydrologic gradient from seasonal wetlands of short flood duration to permanently flooded sites. My results indicate that wood frogs have greatest reproductive effort and success in …

Regulation Of Vitellogenin And Other Serum Proteins By Estrogen And Xenobiotic Estrogens In Salamanders, Lisa Marie Nespoli

Electronic Theses and Dissertations

Environmental estrogens pose potential health risks to humans and wildlife by disrupting physiological and developmental processes; therefore, our laboratory has been designing in vivo bioassays on induction of the egg-yolk precursor protein vitellogenin. I have provided information on vitellogenin induction by estrogens in tiger salamanders (Ambystoma tigrinum), spotted salamanders (Ambystoma maculatum), hellbenders (Cryptobranchus alleganiensis), Morelet's crocodiles (Crocodylus moreletii), and developed vitellogenin immunoassays in these species. Salamanders were estrogen-injected; blood was collected at intervals. Estrogen exposed male salamanders of all species, produced substantial quantities of a 200-kDa protein, the approximate size of vertebrate vitellogenins. Sequencing of estrogen-induced proteins showed substantial homology …

Survey And Comparison Of Amphibian Assemblages In Two Physiographic Regions Of Northeast Tennessee., Marquette Elaine Crockett

Electronic Theses and Dissertations

Declines in amphibian populations have prompted study of their ecology and distribution. The purpose of this study was to survey two sites located within different physiographic and one herpetofaunal region of Northeast Tennessee, comparing species composition and activity. The first, Henderson Wetland, is in the Appalachian Ridge and Valley physiographic region. The second, John's Bog, is in the Blue Ridge. Survey methods included random walks, aural surveys, and point source collections during a 16-month period (February 1999 to May 2000).

Nine caudate (Plethodontidae) and one anuran species (Ranidae) were found in John's Bog. Seven caudate (Ambystomatidae, Plethodontidae, Salamandridae) and five …

Distribution Of The Herpetofauna Of Kentucky., Symoine Kamin Laufe

Electronic Theses and Dissertations

Although the herpetofauna of Kentucky is extensive and varied. it has received much less attention than that of most other states. Many herpetologists have reported on various phases of the state's amphibians and reptiles, but for the most part these reports are discrete, either pertaining to a collection, or a generic or specific study. Hence, there is no single adequate work which aptly describes the herpetology of Kentucky as a whole. When one realizes the keystone position of Kentucky in relation to northern and southern forms, the need of a zoogeographical summary of the state becomes even more apparent. Therefore, …