Marine Biology Commons^™

Use Of Hematological Markers To Assess Physiological Condition And Health Status In Free-Ranging Sand Tiger Sharks (Carcharius Taurus), Chestina N. Craig

Electronic Theses and Dissertations

The contents of blood can provide information about the physiological condition and health of vertebrates. This study seeks to better understand the stress physiology and blood bacteria presence of the sand tiger shark (Carcharius taurus), as sharks are known to have unique physiology and immune systems. In this study the blood metabolites glucose, lactate, and ketones (3-hydroxybuteric acid and acetoacetate), were used to understand how biotic and abiotic factors affect the acute stress response to capture and handling. Metabolite concentrations from blood plasma were analyzed using colorimetric assays. Glucose and ketones showed no significant responses to capture and …

Effects Of Synthetic Estrogen (17Α-Ethinyl Estradiol) On Male Fiddler Crab Aggression, Micayla Shirley

Honors College Theses

Pharmaceuticals, including hormones and antibiotics, are considered contaminants due to their widespread use and release into the environment. Hormones, like the synthetic estrogen used in oral contraceptives (17α-ethinylestradiol), are present in freshwater and marine systems, but with relatively unknown effects on the organisms that live there. Ethinylestradiol (EE2) accumulates in waterlogged soil (sediment) with potential to harm sediment-dwelling animals. For example, fiddler crabs (Uca pugilator) are vital members of salt marsh communities. Their burrowing adds oxygen to sediments and cycles nutrients, and they are an important food resource to birds and raccoons. Male fiddler crabs are territorial, aggressively …

Assessing Habitat Suitability Of Ribbed Mussels (Geukensia Demissa) In Georgia Salt Marshes By Examining Predicted Mussel Densities And Mussel Population Parameters, William K. Annis Jr

Electronic Theses and Dissertations

Geukensia demissa (ribbed mussel) is an ecology important bivalve that has the potential to contribute to salt marsh restoration. Understanding the factors that contribute to the distribution of mussels can help inform managers on choosing locations to optimize the survivorship of mussels in restoration projects. This study sought to model mussel densities across the coast of Georgia and to compare predicted mussel densities with mussel population parameters as means to gauge habitat suitability. Mussel densities were collected through field surveys across a range of salt marshes along the coast of Georgia and were compared with spatial data such as distance …

Evaluating Elasmobranch Bycatch And Shark Depredation In The Georgia Shrimp Fishery, Matthew M. Scanlon

Electronic Theses and Dissertations

The Georgia shrimp fishery has seen a dramatic decrease in profit and productivity since the 1980’s due to a number of economic factors. Additional, yet undocumented, pressures on this fishery include interactions between foraging sharks with trawl gear. Fishermen report that sharks frequently bite nets in an attempt to prey on netted fish, resulting in large holes in the gear. Further elasmobranch interactions with trawl gear occur as bycatch; shrimp trawls represent nearly 100% of elasmobranch commercial bycatch in Georgia state waters, the species composition of which is largely unstudied. Shark interactions with nets were detailed through fishery-dependent observations on …

The Biological Stress Response In Bluegill Sunfish (Lepomis Macrochirus) To Variations In Environmental Temperature And Dissolved Oxygen Content., Monique Kellman

Honors College Theses

With the predicted increase in global water temperature and acute hypoxic episodes, knowledge of the effects these stressors can have on local aquatic life is extremely valuable. This study thereby quantified the change in metabolic rate in Bluegill sunfish, in response to increased temperature and low dissolved oxygen concentration, by utilizing intermittent flow respirometry. Both maximum metabolic rate (MMR) and resting metabolic rate (RMR) were determined in response to variations in dissolved oxygen content, specifically > 95% O₂ and 40% O₂. Additionally, three temperature treatment groups were established, with temperatures of 20, 25 and 30°C in order to …

Relative Abundances Of The Recently Introduced Barnacles, Megabalanus Coccopoma And An Unidentified Species Of Megabalanus, In The Southeastern U.S., Jennifer L. Tyson

Honors College Theses

ABSTRACT

Megabalanus coccopoma is a prominent invasive species off the coast of Georgia. Recently, among collected samples thought to be M. coccopoma, several individuals of an unidentified species of barnacle were found. The species has been identified as a Megabalanus species, but is still unidentified to the species level. Species identification is difficult due to morphological variation, inconsistent taxonomic keys, and unknown origin. In this study I developed a method to accurately distinguish M. coccopoma from the unidentified Megabalanus sp. using sequence differences in the mitochondrial Cytochrome Oxidase I (COI) gene. This study will provide an accurate estimate of …

Molecular Population Genetics Of The Atlantic Sand Fiddler Crab, Uca Pugilator, Along The Atlantic Coast, David A. Weese

Electronic Theses and Dissertations

Author's abstract: The Atlantic sand fiddler crab, Uca pugilator, is an extremely abundant fiddler crab found along the eastern and Gulf coast of the United States. Fiddler crabs have a life cycle with an obligatory planktonic larval phase of 30-90 days, which might be expected to lead to widespread larval dispersal and consequent genetic homogeneity over considerable distances. However a large amount of morphological and behavioral variation is found between northern and southern populations along the eastern coast. This study was undertaken to determine the population genetic structure of U. pugilator and to determine whether these differences may have a …