Ecology and Evolutionary Biology Commons^™

Modeling Early Life: Ontogenetic Growth And Behavior Affect Population Connectivity In Gulf Of Mexico Marine Fish, Kelly Vasbinder

USF Tampa Graduate Theses and Dissertations

This dissertation is an examination of growth, behavior, and dispersal during the early life stages of marine fishes in the Gulf of Mexico. Understanding movements of early life stages is a key part of managing exploited fish populations. Position in the water column can impact larval dispersal, since it determines those currents to which larvae are exposed. First, I investigated the relationship between length and age in early life stages of marine fishes. I found that demersal fish taxa tend to be represented by exponential models, while pelagic fish tend to be represented by linear models. I suggest this may …

Cross-Host Correlations And Multivariate Effects Of Herbivore Specialization, Daniel J. Zydek

USF Tampa Graduate Theses and Dissertations

The distribution of insect herbivores among plant hosts is largely nonrandom: most herbivores have limited sets of hosts within one or a few plant families. This host use specialization is reinforced by traits that confer differential fitness across host plant species. Classic explanations for herbivore specialization predict that evolutionary trade-offs reinforce these relationships by imposing costs in the form of reduced potential fitness on alternative hosts, due to negative genetic correlations in fitness across hosts. This prediction that trade-offs constrain host use in herbivores can be tested with experimental evolution, by showing the direct evolutionary effects of host manipulation on …

Environmental Influences On Expression Of Virulence- And Survival-Associated Genes And Epigenetic Modifications Of Dna In Vibrio Vulnificus, James W. Conrad

USF Tampa Graduate Theses and Dissertations

Vibrio vulnificus is an autochthonous inhabitant of warm, brackish coastal waters and is an opportunistic pathogen that causes the highest mortality of all seafood-related illnesses (1). These fatal infections are generally caused by the clinically-associated vcgC/16S rRNA type B genotypes within the biotype I group (2–5). However, the reasons for the heightened infectiousness of the clinically-associated strains over environmentally-associated ones remains elusive, as no unique clinically-associated virulence genes have been identified through genomic sequencing or other strategies. DNA methylation may contribute to regulation of virulence by affecting gene transcription, and was investigated in the highly virulent V. vulnificus strain CMCP6. …

Reproduction And Parasite-Mediated Selection, Meredith A. Krause

USF Tampa Graduate Theses and Dissertations

Sexual reproduction generates genetic diversity that can help hosts respond to selection by parasites, and in this thesis, I test three predictions on how reproduction impacts predictions by the parasite theory of sex and the Red Queen hypothesis. In Chapter one, using a meta-analysis, I found that asexuals (lower genetic diversity) have more parasites than sexuals (higher genetic diversity), but this difference can be heavily mediated by the mode and origin of asexuality. Further, hybridization but not polyploidy can blunt predicted differences in parasite loads among sexual and asexual hosts. In Chapter two, I flip the perspective of Red Queen …

Feeding Specificity Of The Photosynthetic Sacoglossan Sea Slug Elysia Papillosa, Kourtney Sui Barber

USF Tampa Graduate Theses and Dissertations

The sacoglossan sea slug, Elysia papillosa is associated with two species of the siphonaceous green alga, Penicillus, which co-occur in mixed macrophyte beds at Tarpon Springs, FL, USA. Field collections revealed that Elysia papillosa is frequently collected from the alga, P. capitatus, but is also present in much lower abundance on P. lamourouxii. Past studies have shown that some species of sacoglossans consume algal species that differ from the algae from which they are collected so, in order to determine whether E. papillosa was consuming either or both species of Penicillus, total DNA was extracted from individual slugs collected from …

Effects Of Inter-Male Status Challenge And Psychopathic Traits On Sexual Aggression, Amy M. Hoffmann

USF Tampa Graduate Theses and Dissertations

Sexual aggression (SA) is a serious social problem that has been linked to a variety of negative physical and mental health outcomes for survivors and produces significant monetary costs to society. In the past five decades, a wealth of research has improved our understanding of the individual and sociocultural factors that contribute to SA perpetration; however, epistemological differences in theoretical approaches to the subject (i.e., evolutionary, feminist) have resulted in gaps in the empirical literature. Informed by both feminist and evolutionary perspectives, this study attempts to examine the ways in which same-gender interpersonal interactions and individual psychopathology interact to produce …

Microbial Community Structures In Three Bahamian Blue Holes, Meghan J. Gordon

USF Tampa Graduate Theses and Dissertations

This study used 16S rDNA metagenomics and water chemistry to conduct an examination of microbial community dynamics and biogeochemistry in three physically adjacent, sunlit blue holes with variable hydrologic regimes on San Salvador Island, Bahamas. Church and Watling’s Blue Holes are holomictic with relatively clear waters, while Inkwell Blue Hole hosts density stratification and waters stained brown with tannins. Based on water color and clarity and physicochemical profiles, I hypothesized Church and Watling’s Blue Holes would be dominated by oxigenic photoautotrophs, and that the bottom layer of Inkwell would be characterized by euxinic (anoxic and sulfidic) conditions and host primarily …

Biogeochemical Cycling Of Nutrients And Carbon In Subtropical Wetlands, Lauren N. Griffiths

USF Tampa Graduate Theses and Dissertations

As human development intensifies, ecosystems around the word are being exponentially destroyed and degraded. Wetlands have the capacity to mitigate some of the possible problems by retaining nutrients and carbon, keeping them from harming downstream ecosystems or being released into the atmosphere. This project focuses on the processes that make wetlands successful by studying two unique ecosystems: 1) a created urban stormwater treatment wetland and 2) mangrove wetlands in Florida and Puerto Rico that were affected by hurricanes in 2017.

The first phase of this study investigates the role of sedimentation and vegetative and algal uptake of nutrients to retain …

The Ecology And Conservation Of An Urban Karst Subterranean Estuary, Robert J. Scharping

USF Tampa Graduate Theses and Dissertations

Sulphur Springs is an artesian spring and part of the limestone karst topography of metropolitan Tampa, Florida, USA. Underlying this spring is an extensive cave system that hosts saltwater vents and conspicuous microbial biofilm communities. For decades, water from Sulphur Springs has been extracted and used to supplement public water supply and dry season flows in the Hillsborough River Estuary. This dissertation describes research conducted at Sulphur Springs to determine the impacts of urban land use on the underlying cave and downstream estuary ecosystems, and presents the use of this system as a model to fill certain ecological knowledge gaps. …

Isotope-Based Methods For Evaluating Fish Trophic Geographies, Julie L. Vecchio

USF Tampa Graduate Theses and Dissertations

Data on the movement and diets of fish during a variety of life stages are important inputs to fisheries stock assessments and marine ecosystem models. Stable isotopes may provide previously inaccessible information on movement and diet of a variety of managed and forage fish species. Here I used several novel means of interpretation for stable isotope data to infer diets and movements of several important fisheries species over both short (weeks to months) and long (lifetime) timescales. To calculate a constant partitioning offset (CPO) between the δ¹⁵N of muscle and of liver tissue, I conducted a literature search …