The blacknose shark (Carcharhinus acronotus) is a common small coastal shark species found in nearshore waters along the southeast coast of the United States, from North Carolina into the Gulf of Mexico and extending further south into the Bahamas. There has been some debate in recent years over the reproductive periodicity of C. acronotus in waters off the U.S. coast. Earlier studies have suggested that Gulf C. acronotus reproduce on an annual basis whereas the Atlantic populations of this species may reproduce biennially. Additionally, there have been no known studies on the diet of C. acronotus. The goal of the present study was to re-evaluate the reproductive biology of the Atlantic populations of C. acronotus with the intent on clarifying discrepancies in reproduction as well as provide information on dietary trends. This was accomplished by examining male and female reproductive tracts and gut contents in animals caught throughout the Atlantic range of C. acronotus. Based on these data, spermatogenesis occurs between late May to early July with peak sperm production occurring in June and July. In females, follicular development is complete by late June-early July with ovulation occurring shortly afterwards. Mating occurs between mid-June and early July based on the presence of fresh mating scars on females captured during this time. Current data suggests that gestation begins late July with parturition occurring late May to early June the following year. As observed in earlier studies, reproductive periodicity appears to be largely biennial. However, evidence for concurrent follicular development and pregnancy was observed in several females, suggesting that at least a portion of the Atlantic population may reproduce on an annual basis. Dietary data shows a dominance of teleost prey items in the diets of C. acronotus with scianids making up the majority of the identifiable teleosts.

Plants and insects are some of the most biodiverse groups in the world and are constantly interacting. One unique interaction that has been observed occurs between carnivorous plants and insects; some plant species are capable of capturing and digesting insects for nutrients. Despite preying on these insects, there are cases where such interactions can been viewed as mutualistic. For instance, a nectar reward is produced by the plant to attract insects, and during visitation insects may fall prey to these plants. Additionally, carnivorous myrmecophytic plants may receive an added indirect benefit in the form of reduced herbivory, since ants have the ability to indirectly protect and drive off herbivores from the plant. However, this type of indirect defensive benefit has been rarely observed in carnivorous plants. To determine the nature of the relationship between carnivorous plants and ants, a predator-exclusion experiment was performed in situ using a natural population of the hooded pitcher plant, Sarracenia minor. The presence of the red imported fire ant, Solenopsis invicta, was manipulated in the pitcher plant population to determine if the presence of this non-native ant affects the survival and growth of this carnivorous pitcher plant. From June-November 2014 mean pitcher height and width, number of pitchers, and proportion of pitchers with herbivory present was recorded monthly. Results indicated that pitcher width (p = .042) and the number of pitchers (p = .038) was significantly lower when the presence of S. invicta was reduced. Specifically, the limited presence of S. invicta led to a 21% reduction in mean number of pitchers and a 2.2% reduction in mean pitcher width. This indicated that this non-native ant does provide a direct nutritional benefit for the plant. However, the presence of the ant had no effect on pitcher height and the proportion of pitchers with herbivory present. But, when the proportion of pitchers with herbivory present was compared to a previous native ant study, herbivory proportions where similar or lower when taking the number of ants present into account. This suggests that this non-native ant and native ants equally provide defensive benefits for this native threatened species. Overall, this studied illustrated that carnivorous plants may exhibit similar multiple benefits from a single interaction with a non-native insect that is both prey and provides defense against herbivores.

Climate change and increasing sea level elevation are predicted to increase salinity in estuarine tidal wetlands in the Southeastern United States. Since much of the ecosystem function in these areas is predicated upon salinity regimes, many fundamental changes are likely to occur as a result. The influence of salinity and SO4 2- reduction on PO4 3- release from tidal wetland soils was evaluated along a salinity gradient at three sites in The St. John’s River, Florida using both field and laboratorybased methods. Porewater was sampled over the course of 10 months to determine ambient levels of SO4 2- and PO4 3-. Lab-based experiments, soils samples were subjected to seawater and SO4 2- treatments in an attempt to induce PO4 3- release. Salinity was lowest at Sixmile Creek (0.45 ± 0.1 g kg-1) and Goodby’s Creek (2.05 ± 2.3 g kg-1) and much higher at Sister’s Creek (27.81 ± 3.1 g kg-1). The organic content of soils was highest (82.35% ± 5.11) at Sixmile Creek, intermediate at Goodby’s Creek (64.45% ± 7.02) and lowest at Sister’s Creek (32.11% ± 9.61). Total soil P was highest at the freshwater Sixmile Creek (1101.64 ± 220.2 μg g-1), intermediate at the brackish Goodby’s Creek (719.61 ± 114.3 μg g-1) and lowest at the Sister’s Creek saltmarsh (475.85 ± 110.9 μg g-1). Porewater PO4 3- was higher at Sixmile and Goodby’s Creek sites (9.44 ± 15.6, 8.99 ± 14.7 !g L-1, respectively) compared to Sister’s Creek (0.6 ± 3.1 !g L-1). Porewater SO4 2- was lower at Sixmile (70.73± 57.58 !g L-1) and Goodby’s Creeks (124.35 ± 152.5 !g L-1) compared to Sister’s Creek (1931.41 ± 557.82 !g L-1). Temporal and spatial trends indicated that SO4 2- and PO4 3- in porewater was likely due to floodwater content and that direct reaction between analytes in soils was unlikely. The addition of aerated seawater failed to cause PO4 3- release from any sites. The incubation of soils under anaerobic conditions, in the presence of Na2SO4 induced SO4 2- reduction, but inhibited PO4 3- flux from both Sixmile and Goodby’s Creek, which is attributed here to likely S- toxicity (Roychoudhury et al., 1999). PO4 3- flux from Sister’s Creek increased in association with Na2SO4 concentration, likely due to more Fe availability to mitigate Stoxicity. Ambient seawater additions to soils under anaerobic conditions followed a similar trend, but the results were not statistically conclusive. Overall, both field and labbased data indicated that Tidal wetland porewater PO4 3- likely originates from floodwaters and that increased salinity and SO4 2- reduction did not directly enhance soil PO4 3- fluxes.

Harmful algal blooms are exponential increases in autotrophic microorganisms that proliferate in such a way that the surrounding environment, the local economy and the health of regional populations are negatively affected. Among the causes of these blooms are anthropogenic inputs of excess nitrogen and phosphorus into the environment through overfertilization. Floating treatment wetlands (FTW) have emerged as a novel method of reducing the negative impacts of these nutrient inputs by using artificial rafts to float normally emergent wetland plants on the surface of water bodies to assimilate excess nutrients. Because their use is so new, only limited research has been performed on their effectiveness. This mesocosm-level study evaluated the performance of a FTW consisting of a community of yellow canna (Canna flaccida), blue flag iris (Iris hexagona) and bulltongue arrowhead (Saggittaria lancifolia) in simulated stormwater of varying nitrogen and phosphorus concentrations. The community of plants displayed nitrogen limitation, while the cyanobacteria-dominated algal community that developed displayed phosphorus limitation, leading to the conclusion that in order for this community of macrophytes to limit algal growth, nitrogen must be present to support their growth and concurrent assimilation of the algae-limiting nutrient phosphorus. Canna and iris were found to significantly outperform arrowhead in terms of biomass gains. The study also showed that the size of the plants may be of great importance in the ability of FTWs to limit algal development. Despite the fact that the community of plants in this study were unable to limit the development of algae, the use of FTWs remains promising and further research should be done to continue to enhance our understanding of their strengths and weaknesses.

Across populations, bottlenose dolphins (Tursiops sp.) exhibit a fission-fusion pattern of associations, in which group size and composition change fluidly throughout the day. Beneath this seemingly ephemeral social structure, considerable variation exists across study sites. While females typically have moderate bonds with one another within a large social network, male-male bonds are variable, though males typically take one of two strategies; some males encounter females individually for opportunities to breed while others cooperate within a first-order alliance to collectively herd females. In addition, multi-tiered alliances in which two first-order alliances cooperate to defend or assist in the theft of a female have been documented within Shark Bay, Australia. However, these patterns do not apply to all study sites, as intersexual bonds are strong within several bottlenose dolphin populations. Given the variation in the presence and complexity of male alliances, greater documentation of social structure and male mating strategies across study sites is needed to draw conclusions as to the ultimate factors behind alliance formation. As such, chapter one documents the inclusion of a new study site in the St. Johns River (SJR) in Northeast Florida where males form first and second-order alliances. In addition, variables from the SJR are included within a meta-analysis in chapter two, the first systematic examination of what variables correlate with alliance presence and complexity, with the conclusion that male-male competition best describes the patterns seen in male alliance formation. Chapter three builds upon this conclusion by examining seasonal trends in tooth rake marks, a proxy for aggression, across the sexes and males of two different mating strategies, ultimately highlighting the potential for non-reproductive aggression. Together, this work provides greater insight as to the social structure and mating patterns of bottlenose dolphins, as well as to the ecological pressures that result in complex sociality.

Glucose is transported in crustacean hepatopancreas and intestine by Na+-dependent co-transport, while Na+-dependent D-fructose influx has only been described for the hepatopancreas. It is still unclear if the two sugars are independently transported by two distinct cotransporter carrier systems. In this study lobster (Homarus americanus) hepatopancreas brush border membrane vesicles (BBMV) were used to characterize, in detail, the cation-dependency of both D-[3H] glucose and D-[3H] fructose influxes, while in vitro perfused intestines were employed to determine the nature of cation-dependent sugar transport in this organ. Over the sodium concentration range of 0-100 mM, both 3H-D-glucose and 3H-D-fructose influxes (0.1 mM; 1 min uptakes) by hepatopancreatic BBMV were hyperbolic functions of [Na+], exhibiting Km values of 2.30 ± 0.59 and 2.58 ± 0.95 mM, respectively. D-[3H] glucose and fructose influxes by hepatopancreatic BBMV over a potassium concentration range of 15-100 mM were hyperbolic functions of [K+], exhibiting Km values of 9.85 ± 0.41 and 12.6 ± 0.80 mM respectively. Both sugars displayed significant (p < 0.01) Na+/K+-dependent and Na+-independent uptake processes. Transepithelial 25 μM D-[3H] glucose and D-[3H] fructose fluxes across lobster intestine over a luminal sodium and potassium concentration range of 0 – 50 mM and 5-100 mM, respectively, were hyperbolic functions of luminal [Na+] and [K+]. As with hepatopancreatic sugar transport, transepithelial intestinal sugar transport exhibited both significant (p < 0.01) Na+/K+-dependent and Na+-independent processes. Results suggest that both D-glucose and D-fructose are transported by a single carrier process in each organ with sodium being the preferred cation for both sugars in the hepatopancreas, and potassium being the preferred cation for both sugars in the intestine.

The metabolic hormones ghrelin, growth hormone, and insulin-like growth factor I are influenced by developmental age, sex, and nutritional status in domestic and free-ranging species. However the role these hormones play has not previously been explored in sub-tropical/ tropical mammals. Furthermore, the seasonality of species with less dynamic environmental cues, such as the West Indian manatee, have not been studied. The West Indian manatee is and endangered species distributed in the southeastern United States and throughout the Caribbean basin, and its nutritional physiology is influenced by environmental factors. Understanding the hormone response to nutritional status in this species and its seasonality will enhance our knowledge of the links between season, nutrition, and life history. The purpose of this research is to understand the biology and seasonal patterns of metabolic hormones in free-ranging manatees which will allow us to assess the nutritional status of wild populations. The research objectives include validation assays to accurately quantify hormone concentrations in manatees. Hormones were quantified in manatee serum using heterologous radioimmunoassay. Hormones were then evaluated between summer, fall, and winter and compared to body composition. Developmental patterns were also assessed. Lastly, hormones were examined between Florida and Antillean manatee populations. Manatees exhibited differences in GH, IGF-I, and body composition demonstrating seasonality similar to other species. Manatees exhibited differences between age classes suggesting decreased growth rate as the animals age. Differences were detected between populations. This research suggests that ghrelin, GH, and IGF-I can be used to indicate nutritional status and detect seasonality and developmental age in the manatee. This could prove to be a valuable tool in rehabilitation facilities and during captures and health assessments to provide better veterinary care and further improve overall health and body condition to better manage the survival of the species.

Harmful algal blooms (HABs) are found worldwide, particularly in places where warm, well-lit, and stagnant waters are common. HABs can have negative effects on aquatic plants and wildlife due to the reduction in light availability associated with turbidity, decrease in O2 availability, and the production of secondary metabolites that can harm or even prove lethal. Aquatic ecosystems are regularly being affected by elevated salinity because of recent water management strategies, episodes of drought, and salt water intrusion. This research focused on how salinity levels ranging from 0-10ppt affected physiological attributes such as cellular growth and abundance, cell mortality, toxin release, and oxidative stress in the toxigenic cyanobacterium, Microcystis aeruginosa. It was determined that salinity treatments of 7ppt and above caused a decrease in both cellular growth and abundance, as well as an increase in toxin release due to cell mortality. M. aeruginosa was able to survive in salinities up to 7ppt. A pattern of caspase activity in response to elevated salinity was shown, but whether cellular mortality was due solely to programmed cell death (PCD) was not definitive. A strong antioxidant response, measured through catalase activity, was noted when salinity was enhanced to 7ppt. Above this value, the damaging effects of salinity caused elevated levels of reactive oxygen species (ROS) production and cell death. It was determined that the maximum amount of hydrogen peroxide that M. aeruginosa could withstand without significant impact to growth and abundance was below 250µM. Salinities of 7ppt and above had a negative impact on the physiology of M. aeruginosa, leading to cell death and an increase in microcystin release into the environment. These two factors can lead to fish kills, poor drinking water, and other recreational and commercial problems for an aquatic ecosystem. By determining the precise salinity that HAB cellular mortality is imminent, predictive models can be employed to predict the impacts of salt intrusion and groundwater management.

Skeletal muscle wasting is a consequence of numerous physiological conditions, including denervation, corticosteroid treatment, immobilization, and aging. The E3 ubiquitin ligases, MuRF1 and MAFbx, are induced under nearly all atrophy conditions and are believed to play a key role in protein degradation in atrophying muscle. However, the preliminary data described in this study provides new evidence that MuRF1 may also act as a transcriptional modulator of atrophy-induced gene activity, including the regulation of MAFbx and MuRF1 expression. To characterize the transcriptional regulation of MuRF1 and MAFbx, reporter gene constructs containing fragments of the proximal promoter regions of these genes were developed, transfected into C2C12 cells with or without a MuRF1 expression plasmid and monitored for differences in reporter gene activity. The MuRF1 and MAFbx reporters each showed repressed activity in cells ectopically expressing MuRF1 compared to cells that did not overexpress MuRF1. Furthermore, ectopic expression of the myogenic regulatory factors (MRFs), MyoD1 and myogenin, caused significant activation of the MuRF1 and MAFbx reporter constructs. However, co-overexpression of MuRF1 with MyoD1 or myogenin resulted in reversal of MRF induction of reporter gene activity, and synergistic repression of a constructed E-box reporter system. To further characterize the role of the MuRF1 gene product in repression of MuRF1 expression, a MuRF1 RING domain mutant and a MuRF1 c-terminal mutant were created. The mutant constructs were then co-transfected along with MRF expression plasmids and the MuRF1 reporter construct into C2C12 cells and reporter gene activity was assessed. The MuRF1 RING mutant failed to reverse MRF activation of the reporter gene, while the c-terminal mutant successfully reversed activation of the reporter gene. These findings suggest that ubiquitin ligase activity is required for MuRF1 transcriptional regulatory effects. These data offer exciting evidence of a potential new function for MuRF1 as a transcriptional modulator of atrophy-induced changes in gene expression.

Klebsiella pneumoniae is a Gram-negative pathogen associated with numerous infections. Like all Gram-negative bacteria, K. pneumoniae naturally release outer membrane vesicles (OMVs) during all stages of cellular growth. OMVs are composed of the outer membrane components such as lipopolysaccharide (LPS) and outer membrane proteins and contain cytosolic and periplasmic proteins in the lumen. K. pneumoniae is often found to lack an O antigen. The absence of the O antigen has been reported to alter the protein content of the membrane which may further alter the immune response elicited by K. pneumoniae. Therefore the purpose of this study was to analyze the protein content and inflammatory responses of the cellular outer membrane (OM) and the secreted OMVs. A secondary goal of this study was to evaluate any changes to the membrane protein content due to O antigen loss and determine if the loss of the O antigen influences the inflammatory response. This study demonstrated that the cellular OM and OMVs have distinct protein profiles as well as inflammatory responses. OMVs were highly enriched in outer membrane proteins compared to the cellular OM and had a significantly stronger inflammatory response. The protein content of the OM and OMVs were further modified by the absence of the O antigen from the outer membrane. Although there were no significant differences seen in the wild type and O antigen deficient OM inflammatory responses, the loss of the O antigen resulted in OMVs that produced a significantly stronger IL-6 response.