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It's A Small World After All: Insights, Interferences, And Implications Of In Situ Chlorophyll Fluorescence Monitoring In Estuaries, James Silas Tanner Jan 2022

It's A Small World After All: Insights, Interferences, And Implications Of In Situ Chlorophyll Fluorescence Monitoring In Estuaries, James Silas Tanner

UNF Graduate Theses and Dissertations

Concentrations of the photosynthetic pigment chlorophyll a are used as a proxy for phytoplankton biomass by estuarine scientists to study eutrophication, food web dynamics, and harmful algal blooms. Coastal managers use chlorophyll as an indicator of nutrient pollution and for assessments to meet Clean Water Act standards. Chlorophyll a, as measured in the laboratory by extraction from monthly discrete water samples, is a core component of the National Estuarine Research Reserve (NERR) System-Wide Monitoring Program (SWMP). Field-deployable sensors based on the excitation and emission spectra of in situ chlorophyll have not been incorporated into SWMP to date because past …


Revitalizing Conservation And Management Of The American Crocodile (Crocodylus Acutus) In The Dominican Republic, Robert Greco Jan 2022

Revitalizing Conservation And Management Of The American Crocodile (Crocodylus Acutus) In The Dominican Republic, Robert Greco

UNF Graduate Theses and Dissertations

Crocodilian populations declined globally during the 20th century because of overhunting and habitat loss. Some crocodilian populations have recovered recently through legal protections and habitat restoration, but the status of many crocodilian populations are still unknown because of a lack of recent data. The American crocodile (Crocodylus acutus) population in the Dominican Republic (DR) is one of these data-deficient populations, with country-wide surveys not carried out since the 1980s. From May through July 2021 we surveyed areas within DR where C. acutus is still likely residing. Our surveys yielded no crocodile sightings in Monte Cristi, suggesting that …


The Effect Of Visitor Density And Interaction On The Behavior Of Four Ray Species (Hypanus Sabina, Hypanus Say, Pseudobatos Lentiginosus, And Rhinoptera Bonasus) Housed In An Aquatic Touch Pool, Aimee Marie Little Jan 2022

The Effect Of Visitor Density And Interaction On The Behavior Of Four Ray Species (Hypanus Sabina, Hypanus Say, Pseudobatos Lentiginosus, And Rhinoptera Bonasus) Housed In An Aquatic Touch Pool, Aimee Marie Little

UNF Graduate Theses and Dissertations

Human-Animal Interactions (HAI) in zoological institutions are thought to be important in helping visitors to establish a connection with animals and thus making them more likely to contribute to conservation efforts. However, animals can respond to visitor interaction in both negative and positive ways. The growing focus on animal welfare in zoological institutions emphasizes the need for assessing different environmental inputs, including visitor interaction, and how these inputs influence behavioral outputs associated with welfare. A touch pool exhibit presents a novel interactive experience that allows visitors to directly interact with various aquatic species, including elasmobranchs, whose conservation has important implications …


Plant Physiological Responses To Environmental Change In A Marsh-Mangrove Ecotone, Matthew Sturchio Jan 2021

Plant Physiological Responses To Environmental Change In A Marsh-Mangrove Ecotone, Matthew Sturchio

UNF Graduate Theses and Dissertations

Globally, photosynthesis (A) and autotrophic respiration (R) are the two largest physiological processes responsible for CO2 flux. Coastal wetland ecosystems are responsible for some of the highest rates of C sequestration. Marsh grass and mangrove habitats responsible for this service are important in supporting biodiversity and preventing shoreline erosion, yet little is known about how this vegetation will respond physiologically to effects of climate and global change. In the first chapter a warming experiment was used to determine whether a C4 marsh grass (Spartina alterniflora) and a C3 mangrove (Avicennia …


An Investigation Of The Role Of Basigin-Variant-1 In The Immune Response Within The Retina, Abigail D. Tompa Jan 2021

An Investigation Of The Role Of Basigin-Variant-1 In The Immune Response Within The Retina, Abigail D. Tompa

UNF Graduate Theses and Dissertations

The neural retina is considered an immune privileged area, in that the eye attempts to suppress the inflammatory response to preserve vision. If there is damage to the blood-retina barrier, such as in diabetes or macular degeneration, it is possible for monocytes to travel out of the blood vessels and into the retina. While studying retinoblastoma, a research group determined that the protein, Basigin, through its extracellular domain, elicits an immune response by enhancing transcription of the pro-inflammatory cytokine interleukin-6 (IL-6). Basigin is cell adhesion molecule that belongs to the immunoglobulin superfamily. The Basigin gene has two main transcripts, that …


Reproductive Biology Of The Spinner Shark Carcharhinus Brevipinna, Off The Southeast U.S. Coast, Kristin K. Palmrose Jan 2021

Reproductive Biology Of The Spinner Shark Carcharhinus Brevipinna, Off The Southeast U.S. Coast, Kristin K. Palmrose

UNF Graduate Theses and Dissertations

The spinner shark, Carcharhinus brevipinna, is a large coastal shark species that is common on the U.S. southeast coast and caught in both commercial and recreational fisheries. Little research has been conducted on the life history of C. brevipinna in the Northwestern Atlantic, presenting challenges for fishery management. This is especially true for reproductive biology, warranting a need to determine how rapidly individuals are reproducing and contributing to the population. This study aimed to characterize reproduction in C. brevipinna by determining size-at-maturity, reproductive seasonality, periodicity, and fecundity. This was accomplished by analyzing changes in reproductive tract morphology and histology, …


Characterization Of A Scalloped Hammerhead (Sphyrna Lewini) Nursery Habitat In Portions Of The Atlantic Intracoastal Waterway, Bryanna N. Wargat Jan 2021

Characterization Of A Scalloped Hammerhead (Sphyrna Lewini) Nursery Habitat In Portions Of The Atlantic Intracoastal Waterway, Bryanna N. Wargat

UNF Graduate Theses and Dissertations

The scalloped hammerhead shark (Sphyrna lewini) worldwide population has been in sharp decline, and they are currently listed as a globally critically endangered species by the IUCN. This warrants a need to identify and protect critical habitats for the species, such as nurseries, which promote stable populations. A section of the Tolomato River, in northeastern Florida, has shown to host large and consistent numbers of young of year scalloped hammerhead sharks. This gave cause to determine whether this portion of the Atlantic Intracoastal Waterway (ICW) serves as a nursery habitat for the species and to understand how the …


The Relative Contribution Of The Blue Crab (Callinectes Sapidus) To Periwinkle Snail (Littoraria Irrorata) Predation Mortality In The Lower Salt Marsh Intertidal Of Northeast Florida, Amanda Paige Small Jan 2021

The Relative Contribution Of The Blue Crab (Callinectes Sapidus) To Periwinkle Snail (Littoraria Irrorata) Predation Mortality In The Lower Salt Marsh Intertidal Of Northeast Florida, Amanda Paige Small

UNF Graduate Theses and Dissertations

In top-down regulation of ecological communities, predation of grazers is critical for maintaining the presence and growth of essential vegetation. The periwinkle snail (Littoraria irrorata) is a ubiquitous grazer in Atlantic salt marshes that can defoliate patches of Spartina alterniflora when populations are extremely dense. On the east coast of Florida, multiple predators could contribute to periwinkle population control maintaining this critical habitat. This study aimed to determine if the blue crab (Callinectes sapidus) is the primary predator of periwinkle snails in the salt marsh lower intertidal. Tethering was utilized to assess if periwinkle mortality is …


Residency And Sociality Analysis Of Skin Lesions In Bottlenose Dolphins (Tursiops Truncatus) Of The St. Johns River, Fl, Brittney Divittore-Goodrum Jan 2021

Residency And Sociality Analysis Of Skin Lesions In Bottlenose Dolphins (Tursiops Truncatus) Of The St. Johns River, Fl, Brittney Divittore-Goodrum

UNF Graduate Theses and Dissertations

Photo analysis of skin lesions is a non-invasive method to measure the health of cetacean populations. The St. Johns River (SJR) in NE Florida is an estuarine system inhabited by bottlenose dolphins that is characterized by high levels of anthropogenic activity, which can impact dolphin health. Social transmission of disease may influence lesion formation in dolphins; thus this study aimed to determine if skin lesion prevalence and body coverage differed based on 1) the amount of time spent in the SJR annually and 2) sociality measures. The dataset was restricted to three 12-month periods, based on the occurrence of an …


Weak Olfactory Preferences Of The Gall Midge Asphondylia Borrichiae, Associated Fungal Endophytes And Implications On Gene Flow And Host Range Expansion, Frances S. Nagle Jan 2021

Weak Olfactory Preferences Of The Gall Midge Asphondylia Borrichiae, Associated Fungal Endophytes And Implications On Gene Flow And Host Range Expansion, Frances S. Nagle

UNF Graduate Theses and Dissertations

Asphondylia borrichaie is a small fly (Diptera: Cecidomyiidae) that is currently undergoing host-associated sympatric divergence. Asphondylia borrichaie is an ambrosia galler, these insects utilize a host plant for oviposition, but its offspring also rely on a symbiotic fungus (or fungal community) to promote the formation of the gall as well as serve as a food source for the developing larvae. Previous studies indicate that A. borrichaie consists of two host- associated populations based on its original host plant Borrichia frutescens (Asterales: Asteraceae), and another one from the two Iva species (I. frutescens (Asterales: Asteraceae) and I. imbricata …


Benthic Microalgae Response To A Warming Climate And Shift In Foundational Vegetation Species In A Saltmarsh-Mangrove Ecotone, Gabriela Canas Jan 2021

Benthic Microalgae Response To A Warming Climate And Shift In Foundational Vegetation Species In A Saltmarsh-Mangrove Ecotone, Gabriela Canas

UNF Graduate Theses and Dissertations

The ecotone in Northeast Florida is experiencing rapid change as mangroves begin to encroach northward into saltmarsh dominated coastal wetlands. This is especially prevalent within the boundaries of the Guana Tolomato Matanzas National Estuarine Research Reserve where studies are attempting to understand the consequences of more mangroves. Although we are beginning to understand some of the implications of this shift in dominant vegetation, the true effects and the accompanying sustained climatic warming effects on the resilience of wetland habitats and their associated communities remains unknown. Primary producers such as benthic microalgae (BMA) are important food sources in both mangrove and …


Fggy Carbohydrate Kinase Domain Containing Is Induced During Skeletal Muscle Atrophy And Modulates Map Kinase And Akt Signaling, Anastasia L. Smith Jan 2020

Fggy Carbohydrate Kinase Domain Containing Is Induced During Skeletal Muscle Atrophy And Modulates Map Kinase And Akt Signaling, Anastasia L. Smith

UNF Graduate Theses and Dissertations

Skeletal muscle atrophy can result from a range of physiological conditions, including denervation, immobilization, hindlimb unweighting, and aging. To better characterize the molecular genetic events of atrophy, a microarray was performed using skeletal muscle isolated from mice after 3 and 14 days of denervation and compared to control muscle to identify novel atrophy-induced genes. The microarray revealed that FGGY carbohydrate kinase domain containing (Fggy) is expressed in skeletal muscle and is induced in response to denervation. Bioinformatic analysis of the Fggy gene locus revealed two validated alternative isoforms, that we have termed Fggy-L-552 and Fggy-S-387, which have distinct transcription initiation …


Estimating The Heritability Of Plasticity Of Thermal Tolerance And Its Application In The Restoration Of Endangered Caribbean Coral, Matz O. Indergard Jan 2020

Estimating The Heritability Of Plasticity Of Thermal Tolerance And Its Application In The Restoration Of Endangered Caribbean Coral, Matz O. Indergard

UNF Graduate Theses and Dissertations

Abstract

Over the last two centuries anthropogenic activity has elevated atmospheric CO2, creating a greenhouse effect that is predicted to elevate global temperatures 1-4o C within the century. Increases in surface temperature pose a threat to the world’s coral reefs and have been the cause of many mass bleaching events. To combat this new threat, corals must migrate, acclimate, or evolve to rising temperatures. Phenotypic plasticity, or the ability of an individual to express different phenotypes to survive in different environments, is crucial for sessile organisms since it can increase survivability in species incapable of moving to …


Effects Of Abiotic Factors On Host Plant Quality And Community Structure Of The Parasitoid Guild That Attacks Asphondylia Borrichiae Midges On Borrichia Frutescens, Kevin Orta Jan 2020

Effects Of Abiotic Factors On Host Plant Quality And Community Structure Of The Parasitoid Guild That Attacks Asphondylia Borrichiae Midges On Borrichia Frutescens, Kevin Orta

UNF Graduate Theses and Dissertations

Asphondylia borrichiae is a gall-inducing insect that attacks its ancestral host plant Borrichia frutescens: through ovipositional mistakes it has acquired two additional hosts, Iva frutescens and Iva imbricata. Oviposition results in the formation of a gall, a tumor-like growth of plant tissue within which immature A. borrichiae develop. During development, immature A. borrichiae, are attacked by a suite of four generalist hymenopteran parasitoids. Of these, Galeopsomyia haemon and Torymus umbilicatus are facultative hyperparasitoids, more common and exhibit non-random attack patterns. In the present study, soil quality was manipulated through bi-weekly application of either ammonium nitrate fertilizer or sodium …


Implementing Welfare Science: Case Studies In Evidence-Based Zoo Management, Marisa Suzanne Spain Jan 2020

Implementing Welfare Science: Case Studies In Evidence-Based Zoo Management, Marisa Suzanne Spain

UNF Graduate Theses and Dissertations

Animal welfare science is a field that focuses on how we can improve the lives and well-being of animals in human care. Modern welfare science has moved away from simply preventing suffering and on to promoting positive welfare states, a concept that has been coined animal “wellness”. A process called evidence-based zoo management has been implemented in many zoos as a way to promote and ensure wellness. This is the idea that husbandry and housing standards should be evaluated and tested for their efficacy using data rather than relying on traditional best practices. In this manuscript we discuss an informal …


American Alligator (Alligator Mississippiensis) Ecology Within Human-Dominated Landscapes, Eli R. Beal Jan 2020

American Alligator (Alligator Mississippiensis) Ecology Within Human-Dominated Landscapes, Eli R. Beal

UNF Graduate Theses and Dissertations

Urbanization is an ever-increasing threat to wildlife and their habitats, yet research has been limited to a small number of taxa. The American alligator (Alligator mississippiensis) is an apex predator that has surprisingly received minimal attention within urban areas. To investigate the potential effects of urban land use on spatial ecology, we conducted surveys of relative alligator abundance in nine tributaries surrounding the St. Johns River. We used these data to explore the potential effects of urban development on alligator spatial distribution and habitat selection. At the coarse scale, we found no correlation between percent developed land and …


Sindbis Virus Infects Specific Gut Cells For Replication And Dissemination From The Posterior Midgut Of Mosquitoes, Yani P. Ahearn Jan 2020

Sindbis Virus Infects Specific Gut Cells For Replication And Dissemination From The Posterior Midgut Of Mosquitoes, Yani P. Ahearn

UNF Graduate Theses and Dissertations

Abstract

Sindbis virus (SINV), a member of the genus Alphavirus, is the protype virus used to gain insight into other disease-causing Alphaviruses. As a mosquito-borne-virus (arbovirus), SINV transit in adult female mosquitoes includes attachment to the gut lumen and entry into the midgut cells, followed by replication and dissemination into the hemolymph through yet unknown specific mechanisms. Free-mated adult females, aged day 5-7, were fed a viremic bovine blood suspension via blood sausage at a final SINV titer at 107 PFU/ml. Midguts from fully engorged mosquitoes were dissected on day 5 and 7 post-bloodmeal and further examined by immunolabeling using …


Basigin As An Immune Mediator In The Cns, Alicia Gonzalez Jan 2020

Basigin As An Immune Mediator In The Cns, Alicia Gonzalez

UNF Graduate Theses and Dissertations

Chronic inflammation is a hallmark of many neurodegenerative disorders. Although the central nervous system (CNS) can stave peripheral pathogens from crossing the blood-brain barrier (BBB) through a network of continuous endothelia, astrocytes, and pericytes, prolonged exposure to a pathogen can comprise this barrier. Basigin, a cell adhesion molecule, is found on the surface of endothelial cells and has been demonstrated to interact with toll-like receptor 4 (TLR4). TLR4 recognizes lipopolysaccharide (LPS), found on the outer membrane of Gram-negative bacteria. The activation of TLR4 produces pro-inflammatory cytokines, like IL-6. The present study aims to address the expression pattern of Basigin gene …


Functional Analysis Of Fam83d And Dupd1 – Two Novel Neruogenic Skeletal Muscle Atrophy-Induced Genes, Lisa Michelle Cooper Jan 2020

Functional Analysis Of Fam83d And Dupd1 – Two Novel Neruogenic Skeletal Muscle Atrophy-Induced Genes, Lisa Michelle Cooper

UNF Graduate Theses and Dissertations

Fam83d and Dupd1 have been identified as novel genes in skeletal muscle that are upregulated in response to neurogenic atrophy in a mouse model. qPCR analysis reveaed both genes are expressed in skeletal muscle with Fam83d expression being highest during myoblast proliferation, while Dupd1 expression is highest during myotube differentiation. Overexpression of either protein results in inhibition of proper muscle cell differentiation as evidenced by repression of both myosin heavy chain and myogenin expression. Characterization of transcriptional activity revealed both genes are modulated by myogenic regulatory factors and additionally, Dupd1 expression is enhanced by dexamethasone treatment. Assessment of subcellular localization …


Analysis Of Changes In Genes That Lead To Antibiotic Resistance In Klebsiella Pneumoniae 43816, Jasmine R. Anderson Jan 2020

Analysis Of Changes In Genes That Lead To Antibiotic Resistance In Klebsiella Pneumoniae 43816, Jasmine R. Anderson

UNF Graduate Theses and Dissertations

Klebsiella pneumoniae is a Gram-negative bacterium responsible for nosocomial infections such as blood stream infections, meningitis, and septicemia. Clinical isolates confirm K. pneumoniae is increasingly antibiotic resistant (AR) making treatment more difficult. While bacterial exposure to antimicrobial substances is a known cause of the AR phenotype, there still exists gaps in knowledge about the genetic changes responsible for this fitness change. The laboratory Klebsiella pneumoniae 43816 (ATCC 43816) was exposed to sublethal concentrations of Cephalothin for a 14-day period. At the end of the experimental treatment, the adapted population acquired clinical antibiotic resistance along with phenotypic and morphological changes. The …


Evaluation Of The Use Of Alternative Biomarkers As Indicators Of Post-Release Mortality In Blacktip Sharks (Carcharhinus Limbatus), Casey L. Zender Jan 2020

Evaluation Of The Use Of Alternative Biomarkers As Indicators Of Post-Release Mortality In Blacktip Sharks (Carcharhinus Limbatus), Casey L. Zender

UNF Graduate Theses and Dissertations

The release of sharks caught in recreational fisheries or as by-catch in non-target commercial fisheries is generally regarded as a sustainable fishing approach. However, post-release mortality can occur in these fish due to physiological damage sustained during capture. It is important to determine the amount of mortality specifically attributed to capture so losses can be accounted for in population management practices. Previous studies have used electronic tagging and/or measurement of secondary stress indicators in plasma (e.g., pH, levels of lactate, glucose, pCO2) to estimate rates of post-release mortality. These methods may not always be the best approaches, as …


Characterizing The Role Of Neurogenic Atrophy-Induced Protein Phosphatases In Skeletal Muscle, Sydney Ann Labuzan Jan 2019

Characterizing The Role Of Neurogenic Atrophy-Induced Protein Phosphatases In Skeletal Muscle, Sydney Ann Labuzan

UNF Graduate Theses and Dissertations

Dusp4 and Ppme1 have been identified as novel genes in skeletal muscle that are upregulated in response to neurogenic atrophy in a mouse model. Overexpression (OE) of Dusp4 wild-type (Dusp4-WT), as well as a Dusp4 Dominant Negative (Dusp4-DN) in C2C12 cells inhibits proper muscle differentiation potentially through its attenuation of ERK-MAPK signaling. Co-immunoprecipitation analysis shows Dusp4-DN associating with ERK1/2 but not p38, suggesting Dusp4 is specific for ERK1/2 but not p38. Quantitative PCR as well as Western blot analysis confirm that Ppme1 is expressed uniformly during muscle cell proliferation and differentiation. Interestingly, Ppme1 mRNA levels appear to …


Next-Generation Sequencing, Morphology, And Culture-Based Methods Reveal Diverse Algal Assemblages Throughout The Florida Springs, Alyssa Garvey Jan 2019

Next-Generation Sequencing, Morphology, And Culture-Based Methods Reveal Diverse Algal Assemblages Throughout The Florida Springs, Alyssa Garvey

UNF Graduate Theses and Dissertations

Algae are a group of highly diverse photosynthetic organisms found in variety of habitats. As the primary energy base in ecosystems, knowledge of the diversity and presence of certain algal lineages is paramount to our understanding of the trophic state of aquatic habitats. In recent years, the state of Florida has seen an increase of both marine and freshwater algal blooms. Similarly, filamentous algae have begun outcompeting vascular macrophytes throughout many of Florida’s springs as nutrient enrichment from anthropogenic sources increases. Traditionally, the Florida algal spring communities have been assessed using classic morphological methods, which may underrepresent the true biodiversity …


Behavioral Assessment Of Social Structure And Guest Provisioning Program Participation Of Zoo-Housed Giraffes (Giraffa Camelopardalis) Under Varying Spatial Availability., Fatima Ramis Jan 2019

Behavioral Assessment Of Social Structure And Guest Provisioning Program Participation Of Zoo-Housed Giraffes (Giraffa Camelopardalis) Under Varying Spatial Availability., Fatima Ramis

UNF Graduate Theses and Dissertations

Close encounters with animals are considered integral for visitors and are trademark components of traditional educational engagement in zoological parks. As capacity for up-close encounters continue to increase with a simultaneous development in the field of animal welfare science, behavioral assessments on the role of common close encounters is timely. Giraffes (Giraffa camelopardalis) visitor feeding programs are established in approximately 57% of institutions accredited by Association of Zoos and Aquariums. Due to successful breeding and capacity building for zoological giraffe populations, this percentage will likely continue to increase. There is a great deal of variation in the environmental …


Effects Of Aquatic Acidification On Calcium Uptake In White River Shrimp Litopenaeus Setiferus Gills, Maria-Flora Jacobs Jan 2019

Effects Of Aquatic Acidification On Calcium Uptake In White River Shrimp Litopenaeus Setiferus Gills, Maria-Flora Jacobs

UNF Graduate Theses and Dissertations

Previous research regarding aquatic acidification has examined the protonation of the carbonate and does not consider calcium to be a limiting factor. This is the first study to suggest that pH may affect the uptake of calcium in crustacean gills. This project describes ion transport mechanisms present in the cell membranes of white river shrimp Litopenaeus setiferus gill epithelium, and the effects of pH on the uptake of calcium by these means. Partially purified membrane vesicles (PPMV) of shrimp gills were prepared through a homogenization process that has been used previously to define ion transport in crab and lobster gill …


Molecular And Evolutionary Analysis Of Cyanobacterial Taxonomic Methods, Chelsea Denise Villanueva Jan 2018

Molecular And Evolutionary Analysis Of Cyanobacterial Taxonomic Methods, Chelsea Denise Villanueva

UNF Graduate Theses and Dissertations

Cyanobacteria are a group of photo-oxygenic bacteria found in nearly every ecosystem, but much cyanobacterial diversity, in various habitats, has yet to be explored. Cyanobacteria are often conspicuous components of photosynthetic flora, providing significant carbon and nitrogen inputs to surrounding systems. As possible primary colonizers of stone substrates not native to this region, cyanobacteria isolated from headstones may provide biogeographically informative data. An exploratory study of lichen-dominated microbial consortia, growing on headstones, was conducted to isolate and identify novel microaerophytic cyanobacteria, and resulted in the establishment of four novel cyanobacterial taxa. Phylogenetic analyses of photobionts in one tripartite lichen revealed …


Characterization Of Vitellogenesis In The Bonnethead Shark Sphyrna Tiburo, Adrien Kathleen Mowle Jan 2018

Characterization Of Vitellogenesis In The Bonnethead Shark Sphyrna Tiburo, Adrien Kathleen Mowle

UNF Graduate Theses and Dissertations

Vitellogenin (Vtg) is a precursor to yolk-proteins produced in the liver of many invertebrates and non-mammalian vertebrates; its synthesis is stimulated by the hormone estradiol (E2). This study is the first to characterize vitellogenin synthesis in a placental viviparous elasmobranch, the yolk-sac placental bonnethead shark, Sphyrna tiburo. This study focused on determining where and when Vtg is produced, as well as what hormonal factors regulate Vtg production. The liver was confirmed as the site of Vtg production via immunohistochemistry. Immunoreactivity was also observed within granulosa cells of ovarian follicles; further experimentation is needed to determine if this is indicative …


Reproductive Biology Of The Tiger Shark In The Western Atlantic Ocean, Chelsea Shields Jan 2018

Reproductive Biology Of The Tiger Shark In The Western Atlantic Ocean, Chelsea Shields

UNF Graduate Theses and Dissertations

Although tiger sharks are an important apex predator in many ecosystems, little is known about their reproduction. The goal of this study was to determine the size-at-maturity and the reproductive seasonality of tiger sharks in the western Atlantic Ocean. This was achieved using a combination of ultrasonography and measurements of plasma hormone concentrations; in particular, testosterone for males and estradiol and progesterone for females. Steroid hormone concentrations were measured using chemiluminescent assays (CLIA). Maturity was also examined through histology of reproductive organs in females and clasper calcification in males. Females were found to mature between 270 and 310 cm total …


The Effects Of The Red Tide Producing Dinoflagellate, Karenia Brevis, And Associated Brevetoxins On Viability And Sublethal Stress Responses In Scleractinian Coral: A Potential Regional Stressor To Coral Reefs, David A. Reynolds Jan 2018

The Effects Of The Red Tide Producing Dinoflagellate, Karenia Brevis, And Associated Brevetoxins On Viability And Sublethal Stress Responses In Scleractinian Coral: A Potential Regional Stressor To Coral Reefs, David A. Reynolds

UNF Graduate Theses and Dissertations

Coral cover is in decline on a global scale, with increased mortality events being attributed to a number of global and regional stressors. While the impacts of global stressors (e.g. sea surface temperature rise, ocean acidification) are well documented, there is growing interest in identifying and understanding the impacts of regional stressors. The reason for this change in focus is that regional stressors can often work in combination, sometimes synergistically, with global stressors and that stressors on a regional scale tend to be more easily mitigated by management practices. One regional stressor that impacts a myriad of marine organisms in …


Establishing Relationships Among Environmental Stressors, Host Immune Status, And Wasting Disease Susceptibility In The Dominant Seagrass Species Thalassia Testudinum, Paige Joy Duffin Jan 2018

Establishing Relationships Among Environmental Stressors, Host Immune Status, And Wasting Disease Susceptibility In The Dominant Seagrass Species Thalassia Testudinum, Paige Joy Duffin

UNF Graduate Theses and Dissertations

A growing body of evidence supports the observation that marine disease outbreaks, especially those caused by opportunistic pathogens, are increasing in frequency and severity. One genus of such pathogens, Labyrinthula, has been identified as the causative agent of seagrass wasting disease, an epidemic that has historically plagued seagrass beds around the world. It is suspected that pathogenicity is intimately linked to the ability of the host to initiate defense responses, but a lack of compelling evidence prevents any meaningful application of preliminary observations. This body of work investigated the roles of host genotype, host immune status, and environmental stressors …