Aquaculture and Fisheries Commons^™

Freshwater Phytoplankton Populations Detected Using High Pressure Liquid Chromatography (Hplc) Of Taxon-Specific Pigments, Lauren Jeanne Simmons

Theses and Dissertations

Phytoplankton are key primary producers in aquatic ecosystems, and the principle food source for primary consumers. Individual phytoplankton species respond to different physical, chemical and biological parameters, so monitoring taxonomic composition of the phytoplankton community is a means to monitor changes in environmental conditions. Phytoplankton community changes have frequently been monitored by estimating biomass (using chlorophyll a, measured fluorometrically), and taxonomic data obtained from cell counts. While such methods are useful, they are time-consuming. I hypothesized that high pressure liquid chromatography (HPLC) methods, which have been frequently used in marine systems, would allow separation and identification of key pigments. …

Genetic Variation In Potentially Virulent Vibrio Parahaemolyticus From The Northern Gulf Of Mexico, Nicholas Felix Noriea Iii

Dissertations

Vibrio parahaemolyticus (V_p) is a gram-negative bacterium found naturally in marine and estuarine environments. V_p is found in oysters including those which are later consumed by the public. Sub-populations of potentially virulent Vp contain specific virulence factors and are relevant human pathogens capable of causing gastroenteritis, wound infection, and death. The tdh and trh genes, both encoding hemolysins, have been correlated with the majority of clinical V_p isolates but have not been shown to be the definitive virulence factors.

A total of 146 V_p isolates from the northern Gulf of Mexico were collected and probed …

Clam (Corbicula Fluminea) As A Potential Sentinel Of Human Norovirus Contamination In Freshwater, Xunyan Ye

Dissertations

The purpose of this study was to evaluate and validate the use of the clam Corbicula fluminea as a sentinel of human noroviruses (HuNoV) contamination in freshwater. The first specific aim was to develop a new method to extract HuNoV RNA from contaminated bivalves (e.g. oysters, clams) that would be much faster than existing methods. The procedure developed includes an initial total RNA extraction using TRI Reagent, followed by HuNoV RNA concentration and purification using biotinylated probe-capture technology. HuNoV RNA is finally detected by real-time RT-PCR. Using bivalve homogenates spiked with HuNoV, 100 PCR detection units of the virus was …

Introduced Chinook Salmon (Oncorhynchus Tshawytscha) In Lake Huron: Do They Spawn At The Right Time?, Meghan T. Gerson

Electronic Thesis and Dissertation Repository

Chinook salmon (Oncorhynchus tshawytscha), following their introduction to the Great Lakes, have successfully colonized many tributaries. Under the hypothesis that colonization success is facilitated by intrinsic factors (i.e., preadaptation), I predicted that patterns of reproductive timing in an introduced population would show similarities with those in their native range. To test this prediction, attributes of reproductive timing were characterized in Chinook salmon from the Sydenham River, Ontario. In their native range, female Chinook salmon exhibit a seasonal decline in reproductive lifespan, a decline in fat stores, low egg retention at death (< 0.5%), and spawning at temperatures below 12.8°C. In contrast, Sydenham River Chinook salmon showed no seasonal decline in reproductive lifespan or fat stores and nineteen of twenty females had egg retention greater or equal to 0.5%. Also, many individuals (30%) spawned when water temperatures exceeded 12.8°C. Thus, individuals do not appear to be pre-adapted in this system.

Nutrient Transport By Shrimp Hepatopancreas, Tamla A. Simmons

UNF Graduate Theses and Dissertations

Purified brush border membrane vesicles (BBMV) were isolated to characterize primary cellular transport mechanisms for white shrimp. The ultimate goal is to determine the effective components of a shrimp’s diet, thereby enhancing growth, as well as nutrient content. Juvenile shrimp are dependent on plant material as a food source. Potassium is a key component of plants, thus it may play a role in nutrient transport. In addition, divalent metals have been shown to act as co-transporters in several other organisms, thus they may serve as a transport mechanism for shrimp.

Fresh, live, white or brown shrimp were obtained, and from …