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Articles 31 - 60 of 69

Full-Text Articles in Aquaculture and Fisheries

An Analysis Of Dredge Efficiency For Surfclam And Ocean Quahog Commercial Dredges, Leanne Poussard May 2020

An Analysis Of Dredge Efficiency For Surfclam And Ocean Quahog Commercial Dredges, Leanne Poussard

Master's Theses

Between 1997 and 2011, The National Marine Fisheries Service conducted 50 depletion experiments to estimate survey gear efficiency and stock density for Atlantic surfclam (Spisula solidissima) and ocean quahog (Arctica islandica) populations using commercial hydraulic dredges. The Patch Model was formulated to estimate gear efficiency and organism density from the data. The range of efficiencies estimated is substantial, leading to uncertainty in the application of these estimates in stock assessment. Analysis of depletion experiment simulations showed that uncertainty in the estimates of gear efficiency from depletion experiments was reduced by higher numbers of dredge tows per experiment, more tow overlap …


Short-Term Estimate Of Finfish Bycatch Discards In The Inshore Artisanal Shrimp Fishery Of Guyana, Leanna Kalicharan, Hazel A. Oxenford Jan 2020

Short-Term Estimate Of Finfish Bycatch Discards In The Inshore Artisanal Shrimp Fishery Of Guyana, Leanna Kalicharan, Hazel A. Oxenford

Gulf and Caribbean Research

The artisanal shrimp fishery in Guyana is important for livelihood and food security, involving around 300 vessels owned and crewed exclusively by Guyanese nationals. This fishery uses Chinese seines and operates in major river estuaries. It targets penaeid shrimp, but also retains some finfish and is known to discard a significant but undocumented quantity of smaller finfish bycatch. The lack of knowledge regarding the bycatch is a concern for fishery management and biodiversity conservation. In this study, we quantify for the first time the finfish bycatch discards through onboard observations (July—August 2016) of a single typical vessel operating in the …


Life History Metrics Of Wahoo (Acanthocybium Solandri) From The Northern Gulf Of Mexico, Erik T. Lang, Chris A. Levron, Cijii D. Marshall, Brett J. Falterman Jan 2020

Life History Metrics Of Wahoo (Acanthocybium Solandri) From The Northern Gulf Of Mexico, Erik T. Lang, Chris A. Levron, Cijii D. Marshall, Brett J. Falterman

Gulf and Caribbean Research

Wahoo (Acanthocybium solandri) are highly sought in recreational and commercial fisheries in the Gulf of Mexico (GOM), yet the harvest of Wahoo is currently unmanaged in the GOM region outside of Florida waters. Life history metrics are critical to stock assessments and science-based management. Between 2014-2017, Louisiana Department of Wildlife and Fisheries (LDWF) biologists collected Wahoo otoliths and ovaries (n=198) from the northern GOM Wahoo recreational fishery based in Venice, LA to estimate life history metrics of age, growth, and maturity. A protocol was developed to section and age the small, fragile otoliths. A 2-parameter Von Bertalanffy growth …


Habitat Characterization Of Juvenile Atlantic Tarpon (Megalops Atlanticus) In Isle Of Youth, Cuba, Zenaida M. Navarro-Martínez, Jorge Angulo-Valdés, Lisandra García-Córdova, Aaron Adams Jan 2020

Habitat Characterization Of Juvenile Atlantic Tarpon (Megalops Atlanticus) In Isle Of Youth, Cuba, Zenaida M. Navarro-Martínez, Jorge Angulo-Valdés, Lisandra García-Córdova, Aaron Adams

Gulf and Caribbean Research

Tarpon is considered a ‘Vulnerable’ species by IUCN but is also a highly prized recreational species. It is reportedly abundant in Cuba and may be threatened by high levels of fishing pressure. However, the current knowledge about Tarpon habitat characteristics and ecology in Cuba is very poor, which limit any attempt for its management and conservation. Here we summarize abiotic characteristics of juvenile Tarpon habitats in Lanier Swamp, Isle of Youth, Cuba, which is a RAMSAR site and Faunal Refuge. Three locations in Lanier Swamp were sampled for juvenile Tarpon presence during 2015-2017: Colony Lagoon (CL), Punta Francés Lagoon (PFL) …


First Records For Spawning Of Caribbean Acropora Species In Colombian Mpas, David M. Hudson, Barrett L. Christie, Luis A. Gómez-Lemos, Camilo Valcarcel, Diego Duque, Juan C. Zárate Arévalo, Jaime Rojas, Otto Reyes, Milena Marrugo, Maria Rosa, Israel A. Caicedo Torrado, Diana Tarazona, Carlos Zuluaga Jan 2020

First Records For Spawning Of Caribbean Acropora Species In Colombian Mpas, David M. Hudson, Barrett L. Christie, Luis A. Gómez-Lemos, Camilo Valcarcel, Diego Duque, Juan C. Zárate Arévalo, Jaime Rojas, Otto Reyes, Milena Marrugo, Maria Rosa, Israel A. Caicedo Torrado, Diana Tarazona, Carlos Zuluaga

Gulf and Caribbean Research

Estimates of Colombian Caribbean coral percent cover in the Southern Caribbean are consistent with those throughout the Caribbean Sea, which has declined to about 10% of historical levels in the last few decades. Human activities like destructive fishing techniques in the marine parks have degraded the reefs over the last few decades. Colombia’s Marine Protected Areas (MPAs) have thousands of square kilometers to map and patrol and few resources to devote to scientific and restoration efforts. Efforts to implement sexual reproduction techniques for restoration are starting to successfully propagate and settle corals on ceramic plates for reef deployment in the …


Evaluation Of The Stock Structure Of Cobia (Rachycentron Canadum) In The Southeastern United States By Using Dart-Tag And Genetics Data, Matt Perkinson, Tanya Darden, Maggie Jamison, Matt J. Walker, Michael R. Denson, James Franks, Read Hendon, Susanna Musick, Eric S. Orbensen Aug 2019

Evaluation Of The Stock Structure Of Cobia (Rachycentron Canadum) In The Southeastern United States By Using Dart-Tag And Genetics Data, Matt Perkinson, Tanya Darden, Maggie Jamison, Matt J. Walker, Michael R. Denson, James Franks, Read Hendon, Susanna Musick, Eric S. Orbensen

Faculty Publications

Available tag-recapture and population genetics data for cobia (Rachycentron canadum) in the southeastern United States were evaluated to provide information on population structure and determine the geographic boundary between stocks in the Gulf of Mexico and the Atlantic Ocean. The movements of 1750 cobia were evaluated on the basis of assigned tagging and recapture zones. Genetic samples from an additional 2796 cobia collected during the presumed spawning season were genotyped at 10 microsatellite loci, and standard population genetic statistical analyses were applied to the resulting sample data set. Tag-recapture results indicate that cobia tagged south of Cape Canaveral, …


The Effects Of Salinity On Zootechnical Performance Of Spotted Seatrout (Cynoscion Nebulosus) In Recirculating Aquaculture Systems, Eric Gigli May 2019

The Effects Of Salinity On Zootechnical Performance Of Spotted Seatrout (Cynoscion Nebulosus) In Recirculating Aquaculture Systems, Eric Gigli

Master's Theses

The spotted seatrout (Cynoscion nebulosus) is a euryhaline finfish candidate for marine aquaculture in the northern Gulf of Mexico. Aquaculture of this species currently uses salinities of 25 psu or greater making production challenging in areas where high salinity water is not available. This study aimed to document the effects of salinity on zootechnical performance of spotted seatrout embryos, early larvae, and juveniles in recirculating aquaculture systems to assist with the development of protocols for low salinity culture.

Embryos obtained from a volitional spawn at 29 psu were incubated at three salinities (12.5, 18.75, or 25 psu) until …


The Purr Of The Lionfish: Sound And Behavioral Context Of Wild Lionfish In The Greater Caribbean, Michelle T. Schärer-Umpierre, Carlos Zayas, Richard S. Appeldoorn, Evan Tuohy, Jack C. Olson, Jessica A. Keller, Alejandro Acosta Jan 2019

The Purr Of The Lionfish: Sound And Behavioral Context Of Wild Lionfish In The Greater Caribbean, Michelle T. Schärer-Umpierre, Carlos Zayas, Richard S. Appeldoorn, Evan Tuohy, Jack C. Olson, Jessica A. Keller, Alejandro Acosta

Gulf and Caribbean Research

Passive acoustic technology has become a useful and cost-effective method to collect data with very high temporal resolution that can be used to detect the presence, distribution, and remotely monitor soniferous marine biodiversity. In order to maximize the potential of bioacoustic and soundscape research in the oceans, understanding the association between the different realms of sound sources, species-specific calls and behavioral context of sound production are fundamental. A previously unknown vocalization was associated with a behavioral display of lionfish (Pterois spp.) by recordings with synchronous audio and video at deep coral reefs in both Puerto Rico and the Florida …


Description Of A New Sound Produced By Nassau Grouper At Spawning Aggregation Sites, Timothy J. Rowell, Michelle T. Schärer, Richard S. Appeldoorn Jan 2018

Description Of A New Sound Produced By Nassau Grouper At Spawning Aggregation Sites, Timothy J. Rowell, Michelle T. Schärer, Richard S. Appeldoorn

Gulf and Caribbean Research

This study identified a new sound produced by Nassau Grouper in association with, although potentially not exclusive to, an agonistic interaction at a spawning aggregation. We have also provided a behavioral and acoustic description for identification of this sound in future studies. The discovery of a third type of sound produced by Nassau Grouper further highlights the importance of acoustic communication coupled with visual displays in fishes. Furthermore, identification of a new sound increases the ability to document the presence of this endangered species at spawning sites. Future efforts may reveal that the sound is produced within additional behavioral contexts …


Population Structure, Connectivity, And Phylogeography Of Two Balistidae With High Potential For Larval Dispersal: Balistes Capriscus And Balistes Vetula, Luca Antoni May 2017

Population Structure, Connectivity, And Phylogeography Of Two Balistidae With High Potential For Larval Dispersal: Balistes Capriscus And Balistes Vetula, Luca Antoni

Dissertations

The gray triggerfish (Balistes capriscus) and the queen triggerfish (Balistes vetula) are two exploited reef fish distributed in tropical and temperate shelf waters of the Atlantic Ocean and the Mediterranean Sea. Both species are highly sedentary as adults but disperse pelagic larvae for extended periods of time potentially allowing connectivity across long distances under the action of oceanic currents. In this work population structure, phylogeography, and migration patterns were examined in the two species and contrasted with predictions of larval transport based on surface circulation data. A total of 1,017 gray triggerfish from twelve sampling localities …


Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg May 2017

Life History Of The Non-Native Invasive Red Lionfish (Pterois Volitans) In The Northern Gulf Of Mexico, Alexander Q. Fogg

Master's Theses

Invasive Red Lionfish (Pterois volitans) were first detected in the northern Gulf of Mexico (nGOM) in 2010 and since then their numbers have increased dramatically. From 2010 to 2015, more than 15,000 Red Lionfish were collected opportunistically from the nGOM for this study. Length and weight relationships differed significantly among ecoregions by sex and there was clear sexual dimorphism in size with males being larger and heavier. Red Lionfish age ranged from 0-4.5 years old and males achieved greater growth rate (K) and asymptotic maximum lengths (Linf) compared to females and these parameters were also different …


Bloom Or Bust: Retrospective Analysis Of The Giant Jellyfish, Nemopilema Nomurai (Scyphozoa: Rhizostomeae), Ecology In The East Asian Marginal Seas, Naomi Yoder Dec 2016

Bloom Or Bust: Retrospective Analysis Of The Giant Jellyfish, Nemopilema Nomurai (Scyphozoa: Rhizostomeae), Ecology In The East Asian Marginal Seas, Naomi Yoder

Master's Theses

The Giant Jellyfish, Nemopilema nomurai, is a large-bodied bloom-forming jellyfish that occurs in the semi-enclosed basins of the East Asian Marginal Seas. N. nomurai has bloomed more frequently in the past 20 years than in any period previously recorded. In Japan, recent N. nomurai blooms were responsible for millions of dollars in lost revenue and equipment damage to commercial fisheries alone. This study statistically analyzed 21 environmental factors in connection with N. nomurai occurrence (using occurrence as a proxy for blooms). Eight factors resulted in a statistically significant or marginally significant (p ≤ 0.10), linear or non-linear relationship with …


Growth And Reproduction Of Southern Flounder (Paralichthys Lethostigma) In The North-Central Gulf Of Mexico, Morgan Marie Corey Aug 2016

Growth And Reproduction Of Southern Flounder (Paralichthys Lethostigma) In The North-Central Gulf Of Mexico, Morgan Marie Corey

Master's Theses

Southern Flounder Paralichthys lethostigma is the most commonly harvested flatfish in the north-central Gulf of Mexico (GOM) and supports a major inshore recreational fishery, yet knowledge of the species’ life history is greatly limited. The objective of this research was to describe the growth and reproduction of Southern Flounder in the Mississippi stock. Fish were collected during September 2014 to March 2016 using primarily recreational fishing techniques. Otoliths (n = 313) were sectioned to estimate age, and multiple length-at-age models were fit to total length (TL, mm) and age estimate (y) data. Gonadal tissue samples (n = 221) …


Development Of Genomic Resources For The Evaluation Of Red Snapper, An Emerging Species Candidate For Marine Aquaculture And Stock Enhancement, Adrienne Elise Norrell Aug 2016

Development Of Genomic Resources For The Evaluation Of Red Snapper, An Emerging Species Candidate For Marine Aquaculture And Stock Enhancement, Adrienne Elise Norrell

Master's Theses

The northern red snapper (Lutjanus campechanus) is a highly targeted reef fish candidate for marine aquaculture and stock enhancement in the southern United States. This work aimed to develop genomic resources for the genetic management of aquaculture programs and to investigate population structure using high-throughput sequencing technologies. Eighty-four new microsatellite markers were developed through screening of Illumina paired-end sequencing reads. Microsatellite loci and Single Nucleotide Polymorphisms (SNPs) generated through Restriction Site Associated DNA (RAD) sequencing were assayed in 5 outbred full-sib families to construct a high-density linkage map of the red snapper genome. The map consists of 7,964 …


The Use Of Marine Aquaculture Solid Waste For Nursery Production Of The Salt Marsh Plants Spartina Alterniflora And Juncus Roemerianus, Heather M. Joesting, Reginald B. Blaylock, Patrick Biber, Andrew Ray May 2016

The Use Of Marine Aquaculture Solid Waste For Nursery Production Of The Salt Marsh Plants Spartina Alterniflora And Juncus Roemerianus, Heather M. Joesting, Reginald B. Blaylock, Patrick Biber, Andrew Ray

Faculty Publications

Recent technological advances in marine shrimp and finfish aquaculture alleviate many of the environmental risks associated with traditional aquaculture, but challenges remain in cost-effective waste management. Liquid effluent from freshwater aquaculture systems has been shown to be effective in agricultural crop production (i.e., aquaponics), but few studies have explored the potential for reuse of marine aquaculture effluent, particularly the solid fraction. The purpose of this study was to investigate the use of marine aquaculture solid waste as a nutrient source for the nursery production of two salt tolerant plants commonly used in coastal salt marsh restoration, Spartina alterniflora (smooth cordgrass) …


Age, Growth And Natural Mortality Of Blackfin Snapper Lutjanus Buccanella From The Southeastern United States And U. S. Caribbean, Michael L. Burton, Jennifer C. Potts, Daniel R. Carr Jan 2016

Age, Growth And Natural Mortality Of Blackfin Snapper Lutjanus Buccanella From The Southeastern United States And U. S. Caribbean, Michael L. Burton, Jennifer C. Potts, Daniel R. Carr

Gulf and Caribbean Research

We determined ages of Blackfin Snapper (Lutjanus buccanella Cuvier 1828; n = 622) collected from the southeastern United States coast and U.S. Caribbean from 1979–2015 using sectioned sagittal otoliths. Opaque zones were determined to be annular, forming March – July (peaking in April–June). Blackfin Snapper ranged from 1–27 years and from 180–609 mm total length (TL). Body size relationships for Blackfin Snapper were: TL = 1.09 FL + 0.81 (n = 203, r2 = 0.99); FL = 0.91 TL + 3.38 (n = 203, r2 = 0.99); TL = 1.23 SL + 14.27 (n = 83, r2 = 0.97); FL …


Effects Of Pre-Release Physical Stressors On Post-Release Success Of Hatchery-Reared Spotted Seatrout, Taylor Westbrook Guest May 2015

Effects Of Pre-Release Physical Stressors On Post-Release Success Of Hatchery-Reared Spotted Seatrout, Taylor Westbrook Guest

Master's Theses

Alteration of habitat associated with coastal development and increased demand for food and recreation can result in the depletion of fisheries resources such as the Spotted Seatrout (Cynoscion nebulosus), the Gulf of Mexico’s most popular recreational fish. Stock enhancement, or the release of cultured fish to supplement wild populations, is one potential tool for managing important fisheries resources. Although much effort has gone into marine stock enhancement, the effectiveness of stocking is not well established, and techniques for ensuring success have not been developed. Although the basic biology of the Spotted Seatrout is well known, comparatively little is known about …


Application Of Otolith Chemical Signatures To Estimate Population Connectivity Of Red Snapper In The Western Gulf Of Mexico, Michelle Zapp Sluis, Beverly K. Barnett, William F. Patterson, James H. Cowan, Alan M. Shiller Jan 2015

Application Of Otolith Chemical Signatures To Estimate Population Connectivity Of Red Snapper In The Western Gulf Of Mexico, Michelle Zapp Sluis, Beverly K. Barnett, William F. Patterson, James H. Cowan, Alan M. Shiller

Faculty Publications

Otolith chemical signatures of Red Snapper Lutjanus campechanus from six nursery regions were used to estimate the sources of recruits to four sampling regions in the western Gulf of Mexico (Gulf) and to estimate whether postsettlement mixing of Red Snapper occurs between the U.S. and Mexican portions of the western Gulf. In a previous study, region-specific otolith signatures (element : Ca ratios: Ba:Ca, Mg:Ca, Mn:Ca, Sr:Ca, and Li:Ca; stable isotope delta values: δ13C and δ18O) were developed based on age-0 Red Snapper (2005–2007 year-classes) sampled from the six nursery areas. In the present study, subadult and …


Estimating The Sex Composition Of The Summer Flounder Catch Using Fishery-Independent Data, Jason M. Morson, Eleanor A. Bochenek, Eric N. Powell, Emerson C. Hasbrouck, Jennifer E. Gius, Charles F. Cotton, Kristin Gerbino, Tara Froehlich Jan 2015

Estimating The Sex Composition Of The Summer Flounder Catch Using Fishery-Independent Data, Jason M. Morson, Eleanor A. Bochenek, Eric N. Powell, Emerson C. Hasbrouck, Jennifer E. Gius, Charles F. Cotton, Kristin Gerbino, Tara Froehlich

Faculty Publications

Models that account for sex-specific behavior and population dynamics are becoming more common in the stock assessment of sexually dimorphic fishes. However, such models can be data intensive and require some knowledge or assumptions about the sex ratio of fishery landings. A recent stock assessment review of Summer Flounder Paralichthys dentatus identified the need to account for sex-specific fishing mortality in the assessment model; however, no data on the sex composition of the catch were available. Fishery-independent, sex-specific information for this species is collected annually by the National Marine Fisheries Service's Northeast Fisheries Science Center during their bottom trawl survey. …


Length–Weight And Length–Length Relationships Of The Hogfish, Lachnolaimus Maximus, Off The Northern Coast Of The Yucatan Peninsula, Mexico, Juan E.B. Pérez-Chacón, Alfonso Aguilar-Perera Jan 2015

Length–Weight And Length–Length Relationships Of The Hogfish, Lachnolaimus Maximus, Off The Northern Coast Of The Yucatan Peninsula, Mexico, Juan E.B. Pérez-Chacón, Alfonso Aguilar-Perera

Gulf and Caribbean Research

Described are the length-weight (LWR) and length-length (LLR) relationships of the Hogfish, Lachnolaimus maximus, off the northern Yucatan Peninsula, Mexico. Fish specimens collected (N = 292) with speargun from April to September each year from 2011 through 2013, ranged in size from 16.6-36.5 cm FL and 94-842 g in weight. There were significant differences in hogfish fork length between years (F2,291 = 11.28, p < 0.05), with larger individuals found in 2012. The LWRs calculated were highly significant (p < 0.05, r2 = 0.95 - 0.97; pooled data r2 = 0.95) and significant differences between the slopes of the LWRs (F5,291 = 245.94, p < 0.05) between the three years were detected. Exponent b in the LWRs (2.33 -2.70; pooled data 2.58) …


Clarification Of The Systematics Of The Haploporoidea (Trematoda) With Descriptions Of New Genera And Species, Michael Jay Andres Dec 2014

Clarification Of The Systematics Of The Haploporoidea (Trematoda) With Descriptions Of New Genera And Species, Michael Jay Andres

Dissertations

The superfamily Haploporoidea Nicoll, 1914 comprises two families, the Atractotrematidae Yamaguti, 1939 and the Haploporidae Nicoll, 1914, and the subfamily Cadenatellinae Gibson et Bray, 1982. All members are parasites of the alimentary tract or gall bladder of marine, estuarine, and freshwater herbivorous fishes. Overstreet and Curran (2005a) provided a review of the Haploporidae and recognized four subfamilies, the Chalcinotrematinae Overstreet et Curran, 2005, Haploporinae Nicoll, 1914, Megasoleninae Manter, 1935, and Waretrematinae Srivastava, 1937. In a series of five publications, Blasco-Costa et al. (2009a-e) revised the Haploporinae and erected a fifth subfamily, the Forticulcitinae Blasco-Costa, Balbuena, Kostadinova, et Olson, 2009. The …


Jellyfish, Forage Fish, And The World's Major Fisheries, Kelly L. Robinson, James J. Ruzicka, Mary Beth Decker, Richard D. Brodeur, Frank J. Hernandez, Javier Quiñones, E. Marcelo Acha, Shin-Ichi Uye, Hermes Mianzan, William M. Graham Dec 2014

Jellyfish, Forage Fish, And The World's Major Fisheries, Kelly L. Robinson, James J. Ruzicka, Mary Beth Decker, Richard D. Brodeur, Frank J. Hernandez, Javier Quiñones, E. Marcelo Acha, Shin-Ichi Uye, Hermes Mianzan, William M. Graham

Faculty Publications

A majority of the world’s largest net-based fisheries target planktivorous forage fish that serve as a critical trophic link between the plankton and upper-level consumers such as large predatory fishes, seabirds, and marine mammals. Because the plankton production that drives forage fish also drives jellyfish production, these taxa often overlap in space, time, and diet in coastal ecosystems. This overlap likely leads to predatory and competitive interactions, as jellyfish are effective predators of fish early life stages and zooplankton. The trophic interplay between these groups is made more complex by the harvest of forage fish, which presumably releases jellyfish from …


Culture Of Lobotes Surinamensis (Tripletail), Eric Saillant, Jason T. Lemus, James S. Franks Jan 2014

Culture Of Lobotes Surinamensis (Tripletail), Eric Saillant, Jason T. Lemus, James S. Franks

Faculty Publications

No abstract provided.


Effects Of Coastal Urbanization On Salt-Marsh Faunal Assemblages In The Northern Gulf Of Mexico, Michael R. Lowe, Mark S. Peterson Jan 2014

Effects Of Coastal Urbanization On Salt-Marsh Faunal Assemblages In The Northern Gulf Of Mexico, Michael R. Lowe, Mark S. Peterson

Faculty Publications

Coastal landscapes in the northern Gulf of Mexico, specifically the Mississippi coast, have undergone rapid urbanization that may impact the suitability of salt-marsh ecosystems for maintaining and regulating estuarine faunal communities. We used a landscape ecology approach to quantify the composition and configuration of salt-marsh habitats and developed surfaces at multiple spatial scales surrounding three small, first-order salt-marsh tidal creeks arrayed along a gradient of urbanization in two river-dominated estuaries. From May 3 to June 4, 2010, nekton and macroinfauna were collected weekly at all six sites. Due to the greater abundance of grass shrimp Palaemonetes spp., brown shrimp Farfantepenaeus …


Genetic Variation In Potentially Virulent Vibrio Parahaemolyticus From The Northern Gulf Of Mexico, Nicholas Felix Noriea Iii May 2012

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

Dissertations

Vibrio parahaemolyticus (Vp) is a gram-negative bacterium found naturally in marine and estuarine environments. Vp 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 Vp isolates but have not been shown to be the definitive virulence factors.

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


Effects Of Hypoxia And 4-Tert-Octylphenol On Gene Expression Profiles Of The Sheepshead Minnow (Cyprinodon Variegatus), Arthur Alan Karels May 2012

Effects Of Hypoxia And 4-Tert-Octylphenol On Gene Expression Profiles Of The Sheepshead Minnow (Cyprinodon Variegatus), Arthur Alan Karels

Dissertations

Hypoxia occurs in estuaries of northern Gulf of Mexico and world-wide, with increasing frequency/severity via eutrophication and anthropogenic influences. Hypoxia inducible factors (HIFs) form transcriptional complex and bind DNA at hypoxia responsive elements (HREs) in promoter regions of genes needed for systemic and cellular adaptation of fish to low dissolved oxygen (hypoxia, DO <2.0 mg/ml). Hypoxia-induced activation of HIF-αs can lead to a cascade of downstream activation, such as erythropoietin (EPO). Return to normal DO levels (normoxia), prolyl hydroxylases (PHDs) are activated to degrade HIF-αs back to baseline. Fish are affected by environmental estrogen mimics, like 4-tert-octylphenol (4tOP), binding estrogen receptor alpha (ERα) at estrogen responsive elements (EREs) and activating genes vitellogenin (VTG). Previous research showed overlap or crosstalk between these two mechanistic pathways. Hypoxia triggers unknown factors regulating ERE-mediated ERα signaling pathway, and stressor combinations could increase/decrease hypoxic or endocrine pathway. Research examined molecular/physiological effects of hypoxia (acute and chronic, moderate and severe) and 4tOP (~60μg/L)on adult male and/or female sheepshead minnow (Cyprinodon variegatus). Three genes identified, cloned, and sequenced (HIF-1α, HIF-2α, and PHD3), plus previously identified genes EPO and VTG, were examined in liver/testes exposed to hypoxia and/or 4tOP for cellular/physiological changes. Endpoints examined included mRNA expression from real-time PCR of HIF-1α, HIF-2α, PHD3, EPO, and VTG using cDNA from total RNA extracts, and microarray analyses of genes expressed during the transition from hypoxia back to normoxia. Phylogenetic analyses confirmed isolation of two HIF-α isofoms (HIF-1α and HIF-2α) and the PHD3 isoform. Significant up-regulation of PHD3 occurred within 10 hrs of chronic hypoxia, and persisted when severe (1.5 mg/L) and declined when moderate (~2.5mg/L). Significant up-regulation of HIF-1α and EPO occurred within 30 minutes to 2 hours of onset of acute severe and very severe (~1.08mg/L) hypoxia. Hypoxia acted similar to an estrogen mimic, with huge up-regulation of VTG gene expression in males, and increased VTG levels (additive effect) when hypoxia was combined with 4tOP. Microarray analyses showed 125 genes with significant transcriptional change, with up- or down-regulation from transitions of: (1) hypoxia (72 hrs) to normoxia (74 hrs) and (2) hypoxia+4tOP (72 hrs) to normoxia+4tOP (74 hrs).


Clam (Corbicula Fluminea) As A Potential Sentinel Of Human Norovirus Contamination In Freshwater, Xunyan Ye May 2012

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 …


A Standardized Terminology For Describing Reproductive Development In Fishes, Nancy J. Brown-Peterson Jan 2011

A Standardized Terminology For Describing Reproductive Development In Fishes, Nancy J. Brown-Peterson

Faculty Publications

As the number of fish reproduction studies has proliferated, so has the number of gonadal classification schemes and terms. This hasmade it difficult for both scientists and resourcemanagers to communicate and for comparisons to be made among studies. We propose the adoption of a simple, universal terminology for the phases in the reproductive cycle, which can be applied to all male and female elasmobranch and teleost fishes. These phases were chosen because they define key milestones in the reproductive cycle; the phases include immature, developing, spawning capable, regressing, and regenerating. Although the temporal sequence of events during gamete development in …


Reproductive Life History Of Fundulus Jenkensi And Comparative Development Of Five Sympatric Fundulid Species, Eric Thomas Lang Dec 2010

Reproductive Life History Of Fundulus Jenkensi And Comparative Development Of Five Sympatric Fundulid Species, Eric Thomas Lang

Master's Theses

Fundulus jenkinsi is recognized federally and within the state of Mississippi as a Species of Concern. Little is known about the life history of this coastal killifish, but a detailed reproductive histology study of F. jenkinsi and a diagnostic key of the early life stages of select members of Fundulidae can provide the foundation needed to accurately identify it and quantify reproductive parameters in this rare species in need of conservation. Monthly gonadosomatic index (GSI) of male and female F. jenkinsi were documented, and spawning phases and oocyte stages were examined using reproductive histology. In addition, various stages of …


Life History And Habitat Use Of The Juvenile Alabama Shad (Alosa Alabamae) In Northern Gulf Of Mexico Rivers, Paul Fraser Mickle Dec 2010

Life History And Habitat Use Of The Juvenile Alabama Shad (Alosa Alabamae) In Northern Gulf Of Mexico Rivers, Paul Fraser Mickle

Dissertations

The Alabama shad, Alosa alabamae, is an anadromous species that is in decline and has seen extirpations from impoundments as well as decreased water quality. Alabama shad live in the Gulf of Mexico and ascend Northern Gulf of Mexico Drainages to reproduce early in the year (January-May). The juveniles spend the majority of the year in these freshwater systems before emigrating out to the Gulf of Mexico as late as December.

This dissertation focuses on the juvenile life stages that occur within the Northern Gulf of Mexico drainages. Spawning conditions of the river, as well as the habitat and diet, …