Biology Commons^™

Leafy Sea Dragon, Phycodurus Sp., Kennedi X. Light

PANDION: The Osprey Journal of Research and Ideas

Artist Statement

Leafy sea dragons, Phycodurus sp. are part of the Syngnathidae family. Syngnathidae is a genus made up of seahorses, pipefishes, and sea dragons. All three of the species are known to have beautiful patterning. However, leafy sea dragons got their name from their leafy appendages like their fins and limbs. The reason I chose to draw a leafy sea dragon is due to my own interest in astrobiology. Astrobiology is the study of life in the universe and astrobiologists look for signs of life within the universe. I would like to be an astrobiologist one day and focus …

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 …

Histological Comparison Of Shark Dermis Across Various Ecomorphologies, Olivia Schuitema

UNF Graduate Theses and Dissertations

The integument plays essential roles in the structural support, protection, and hydrodynamic capability among fishes. Most shark skin research has been done on the external epidermal layer containing the dermal denticles, while the larger dermis layer has been mostly ignored. The dermis layer in sharks is composed of two layers, the upper stratum laxum and the lower stratum compactum, holding supportive collagen and elastin fibers. There may be morphological and compositional differences in the dermis layers across various species of sharks, although the extent of such is unknown. These potential differences may be represented by various dermal thicknesses and different …

Why Are You So Slimy?, Lindsay Dillman, James Gelsleichter, Laura Habegger

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The epithelium of vertebrates is a complex tissue that houses a large variety of cells with different functions. One of its most important functions is protection and in many cases this function is achieved by exuding copious amounts of mucous that fight off diseases, harmful toxins and overall protect the species from external invaders. Mucous, made of mucin, is produced by specialized epithelial cells called goblet cells. Among vertebrates’, fishes are perhaps one of the major groups known to produce mucous, particularly stingrays. The Atlantic stingray, Dasyatis sabina is one of the few cartilaginous fishes known to inhabit both freshwater …

Bycatch Reduction Devices As A Method To Reduce Mortality Rates Of Malaclemys Terrapin In Crab Pots, Benjamin Lowstuter, Leslie Delong, Corey Hymel

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Diamondback terrapins (Malaclemys terrapin) currently face population loss along their broad coastal North American range, spanning from Massachusetts down to Texas. This species is suggested to be an important indicator of environmental change within the limited brackish water habitat along the coastlines. Terrapin mortality predominantly stems from human activities, such as commercial and recreational blue crab (Callinectes sapidus) trapping. Once caught in one of many crab pots littered throughout their aquatic habitat, terrapins can easily drown in several hours upon capture. In reviewing published research, the use of bycatch reduction devices (BRDs) have been shown to reduce the number of …

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, …

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 …

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 …

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 …

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 …

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 …

The Function Of Second-Order Male Alliances In St. Johns River Dolphins (Tursiops Truncatus), Arien D. Widrick

UNF Undergraduate Honors Theses

Bottlenose dolphins (Tursiops truncatus) have a sexually segregated fission-fusion society, in which males and females form different types of social groups for different purposes. Social interactions among dolphins are frequent, and group composition changes just as often. Male-male association patterns reveal the formation of alliances, which range in complexity. Recently, second-order alliance formation was confirmed in the St. Johns River, but the function of these alliances is unknown. To investigate their function, this research analyzes the seasonality of first and second-order alliance formation, and whether female presence plays a role. It was hypothesized that higher level male alliances form in …

Tests Of Reproductive Isolation Between The Fishes Fundulus Heteroclitus And F. Grandis, Ruthie E. Barbas

UNF Graduate Theses and Dissertations

The closely related killifishes Fundulus heteroclitus and F. grandis hybridize in a small region where their ranges overlap in coastal northeastern Florida. Hybrids of these species are rare in frequency within the contact zone, suggesting the presence of relatively strong reproductive isolation between these species. The objective of this study was to elucidate barriers to reproduction between F. heteroclitus and F. grandis in the lab, as well as to quantify the relative strengths and contributions of various isolating barriers. Pre-zygotic (mating and fertilization) and post-zygotic (hatching) barriers were investigated by performing a variety of choice and no-choice laboratory mating experiments. …

The Reproductive Biology Of The Finetooth Shark, Carcharhinus Isodon, In The Northwest Atlantic Ocean, Amanda N. Brown

UNF Graduate Theses and Dissertations

Shark fisheries are a multimillion dollar industry in the United States and have significant contributions both recreationally and commercially. In order to maintain this industry, fisheries must be properly managed. An understanding of life history and reproduction is crucial in order to adequately manage shark fisheries. The finetooth shark, Carcharhinus isodon, is a member of the small coastal shark (SCS) fishery complex. It is found in Atlantic waters from South Carolina to Florida and throughout the Gulf of Mexico. This species has recently come under increased fishing pressure and has previously been overfished. New data is needed in order …

Molecular Identification And Functional Characteristics Of Peptide Transporter 1 (Pept1) In The Bonnethead Shark (Sphyrna Tiburo), Hannah Hart

UNF Graduate Theses and Dissertations

Many elasmobranchs are considered top predators with worldwide distribution, and in general these fish play an important role in the transfer of energy from the lower to the upper trophic levels within the marine ecosystem. Despite this, little research has been done regarding the rates of prey ingestion, digestion, and the processes of energy and nutrient absorption. Specifically understudied is enzymatic digestion within the intestinal brush border, which functions to break down macromolecules into smaller subunits for luminal absorption across the gastrointestinal epithelium. Given their carnivorous diet, the present study sought to expand knowledge on nutrient intake in elasmobranchs by …

Functional Characterization Of A Putative Disaccharide Membrane Transporter In Crustacean Intestine, Rasheda S. Likely

UNF Graduate Theses and Dissertations

The mechanisms of transepithelial absorption of dietary sucrose in the American lobster, Homarus americanus, were investigated in this study to determine whether sugars can be transported across an animal gut intact or as monosaccharides following hydrolysis. Lobster intestine was isolated and mounted in a perfusion chamber to characterize the mechanisms of mucosal to serosal (MS) ¹⁴C -sucrose transport across the intestine MS fluxes were measured by adding varying concentrations of ¹⁴C-sucrose to the perfusate which resulted in a hyperbolic curve following Michaelis-Menten kinetics. The kinetic constants of the proposed sucrose transporter were K_M = 15.84 ± 1.81 …

Effect Of Feed Additives On Amino Acid And Dipeptide Transport By Intestines Of American Lobster And Atlantic White Shrimp, Maria Louise Peterson

UNF Graduate Theses and Dissertations

Previous nutritional physiology research using L-histidine and zinc in American lobster intestine (Homarus americanus) has suggested that these solutes can be co-transported as complexes (Histidine-Zinc-Histidine) across the intestine using a peptide transporter. Furthermore, transport of L-leucine was shown to be inhibited by high calcium concentrations. Dipeptide and bis-complex transport and the role of calcium were investigated in the perfused intestines of lobster and Atlantic white shrimp (Litopenaeus setiferus). Following trans-intestinal transport, serosal medium was analyzed for amino acid composition by gas chromatography. In lobster, the transport of glycylsarcosine (Gly-Sar) from mucosa to serosa was stimulated two-fold …

The Social Structure And Mating Strategies Of Bottlenose Dolphins (Tursiops Truncatus) In The St. Johns River, Jessica Lea Ermak

UNF Graduate Theses and Dissertations

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 …

Factors That Affect Distribution Of Two Species Of Killifish In Northeast Florida Marshes, Stacy N. Galleher

UNF Graduate Theses and Dissertations

Fundulus heteroclitus and the closely related F. grondis are mainly distributed along the Atlantic coast of the U.S from Maine to Northeast Florida and from the East coast of Florida throughout the Gulf of Mexico, respectively. Both are resident salt marsh fishes whose range is thought to overlap in Northeast Florida, making them an ideal study system to examine resource partitioning between two closely related species. The objective of this study was to examine the effects of temperature and elevation on potential habitat partitioning of these two species. It is hypothesized that the northern species, F. heteroclitus, would have a …