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Full-Text Articles in Life Sciences
A Quantitative Genetic Analysis Of Commercial Traits In Polyploid Crassostrea Virginica, With An Evaluation Of Strategies For Genetic Improvement Of Triploids, Joseph L. Matt
Dissertations, Theses, and Masters Projects
Triploids are a popular product in commercial oyster aquaculture and make up most of the hatchery-produced Crassostrea virginica farmed in the Chesapeake Bay. Despite their importance to commercial aquaculture, the potential of genetically improving triploid C. virginica from selective breeding and breeding strategies for their improvement had not been evaluated. In this dissertation, the prospect of improving triploid C. virginica through selective breeding was assessed with a quantitative genetic analysis from a field test, and breeding strategies for genetically improving triploids were compared by computer simulation. Heritability and genetic correlations involving commercial traits in triploids, including mass mortality associated with …
Stock Composition Of Striped Marlin (Kajikia Audax) In The Central North Pacific Ocean Inferred By Analyses Of Genome-Wide Molecular Markers, Jackson Martinez
Stock Composition Of Striped Marlin (Kajikia Audax) In The Central North Pacific Ocean Inferred By Analyses Of Genome-Wide Molecular Markers, Jackson Martinez
Dissertations, Theses, and Masters Projects
Relative to many highly migratory fishes, Striped Marlin, Kajikia audax, exhibit considerable stock structure. At least four genetically distinct stocks of Striped Marlin have been delineated in the Pacific and Indian oceans, although stock composition in the central North Pacific (CNP) remains unclear and the presence of an additional stock in the North Pacific has been suggested in two recent studies. The goals of this research were to clarify the number of Striped Marlin stocks in the North Pacific and utilize temporal sampling to better understand the stock dynamics of Striped Marlin exploited by the Hawaii-based pelagic longline fishery (HBPLLF). …
An Assessment Of The Population Genetic Structure And Evidence Of Multiple Paternity In Channeled Whelk, Busycotypus Canaliculatus, Along The Us Atlantic Coast, Samantha E. Askin
An Assessment Of The Population Genetic Structure And Evidence Of Multiple Paternity In Channeled Whelk, Busycotypus Canaliculatus, Along The Us Atlantic Coast, Samantha E. Askin
Dissertations, Theses, and Masters Projects
Channeled whelk (Busycotypus canaliculatus Linnaeus, 1758) are predatory marine gastropods that are found in intertidal regions of the continental slope along the U.S. Atlantic coast from Cape Cod, Massachusetts to Cape Canaveral, Florida. The channeled whelk is a commercially important species that supports a fishery along the Atlantic coast of the United States. The resource is managed at the state level with minimum landing size (MLS) varying by state. Biological assessments of channeled whelk in the mid-Atlantic and Massachusetts have indicated that females have a low probability of being mature when they enter the fishery. The life history characteristics of …
Genetic And Morphological Assessment Of Population Structure Of The Clearnose Skate (Rostroraja Eglanteria) From The Western North Atlantic Ocean, Lindsey Noel Nelson
Genetic And Morphological Assessment Of Population Structure Of The Clearnose Skate (Rostroraja Eglanteria) From The Western North Atlantic Ocean, Lindsey Noel Nelson
Dissertations, Theses, and Masters Projects
The Clearnose Skate (Rostroraja eglanteria, Bosc 1800) is a flat, benthic elasmobranch and member of the family Rajidae. They are widely distributed in the coastal waters of the east coast of the United States and in the northeastern Gulf of Mexico. It has been noted that the physical appearance of Clearnose Skate from the southern end of their range near South Carolina is distinct from individuals found in the northern end of their range near Woods Hole, MA, perhaps suggestive of a sub-species, though this observation has not been further investigated. Clearnose Skate are seasonally migratory and are often incidentally …
Fecundity Of Triploid Eastern Oyster (Crassostrea Virginica) As A Function Of Tetraploid Lineage, Kate Ritter
Fecundity Of Triploid Eastern Oyster (Crassostrea Virginica) As A Function Of Tetraploid Lineage, Kate Ritter
Dissertations, Theses, and Masters Projects
Rapid growth rate and partial sterility have made triploid eastern oysters (Crassostrea virginica) the most popular crop variety for the Virginia oyster aquaculture industry, typically comprising greater than 90% of larvae and juvenile sales. Triploid advantages, however, sometimes come with the disadvantage of higher mortality in late spring and early summer, dubbed “triploid mortality.” In recent years, farms up and down the East Coast, especially Maryland and south into the Gulf of Mexico have experienced triploid mortality. Some of the reports include observations of elevated triploid fecundity. Triploid oysters are created by crossing tetraploids to diploids, and much of the …
Multi-Scale Phylogenomics Of Gadiformes With Emphasis On Hakes (Merluccius, Merlucciidae), Adela Y. Roa-Varon
Multi-Scale Phylogenomics Of Gadiformes With Emphasis On Hakes (Merluccius, Merlucciidae), Adela Y. Roa-Varon
Dissertations, Theses, and Masters Projects
Gadiformes include some of the most important commercially harvested fishes in the world (e.g. cods, hakes, and grenadiers). Currently, different authors recognize anywhere between 11 and 14 families, approximately 84 genera, and over 600 species. The monophyly of the order has been supported by both morphological and molecular data, yet the relationships among families and subfamilies remain poorly understood and interpreting phylogenetic patterns to date has been difficult. My dissertation research on multi-scale phylogenetics of Gadiformes with emphasis on hakes (Merluccius, Merlucciidae) has three primary objectives: (1) to improve the understanding of the phylogenetic relationships among families of Gadiformes (Teleostei); …
Genetic Analyses Of Striped Bass In The Chesapeake Bay: An Investigation Of Connectivity Among Virginia Subestuaries And An Evaluation Of Close-Kinship Mark Recapture Methodology To Estimate Spawning Abundance., Savannah Michaelsen
Dissertations, Theses, and Masters Projects
The striped bass (Morone saxatilis) is an anadromous fish distributed along the eastern coast of North America that currently supports one of the most lucrative and important commercial and recreational fisheries in the region. Since the recovery of the Atlantic stock after a collapse in the late 1970s, studies have focused on understanding the connectivity of major spawning grounds and improving methods of abundance estimation. Studies support strong site fidelity of striped bass to major estuaries along the Atlantic coast, but there has been disagreement about connectivity within the largest spawning ground, the Chesapeake Bay. Additionally, no estimates exist for …
An Investigation Of Hermaphroditism In R Sp Sb 347, Maureen Catherine Farrell
An Investigation Of Hermaphroditism In R Sp Sb 347, Maureen Catherine Farrell
Dissertations, Theses, and Masters Projects
No abstract provided.
Improvements In Triploid Crassostrea Virginica Production: Characterizing The Diploid Parent, Brian R. Callam
Improvements In Triploid Crassostrea Virginica Production: Characterizing The Diploid Parent, Brian R. Callam
Dissertations, Theses, and Masters Projects
The effect of triploidy to effect faster growth and increased survival compared to diploid oysters is called the ‘triploid advantage’ and this advantage in the Chesapeake Bay for Crassostrea virginica is the principal reason for the value of triploid C. virginica in the Chesapeake Bay, USA. The triploid advantage is hypothesized to be the result of genetic effects, physiological changes, or a combination of both. The causative genetic mechanisms at play may include additive genetic effects and heterosis while the physiological changes obtain from triploid sterility. The triploid advantage was examined by comparing 13 diploid and 13 triploid crosses across …
Physiological And Morphological Characterization Of Genetically Defined Classes Of Interneurons In Respiratory Rhythm And Pattern Generation In Neonatal Mice, Maria Cristina De Guzman Picardo
Physiological And Morphological Characterization Of Genetically Defined Classes Of Interneurons In Respiratory Rhythm And Pattern Generation In Neonatal Mice, Maria Cristina De Guzman Picardo
Dissertations, Theses, and Masters Projects
Breathing in mammals depends on an inspiratory-related rhythm that is generated by glutamatergic neurons in the preBotzinger complex (preBotC), a specialized site of the lower brainstem. Rhythm-generating preBotC neurons are derived from a single lineage that expresses the transcription factor (TF) Dbx1, but the cellular mechanisms of rhythmogenesis remain incompletely understood. to elucidate these mechanisms we comparatively analyzed Dbx1-expressing neurons (Dbx1 +) and Dbxl- neurons in the preBotC in knock-in transgenic mice. Whole-cell recordings in rhythmically active newborn mouse slice preparations showed that Dbx1 + neurons activate earlier in the respiratory cycle and discharge greater magnitude inspiratory bursts compared to …
Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo
Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo
Dissertations, Theses, and Masters Projects
Squaloids (Order Squaliformes) are a highle diverse group of mostly deepwater habitats (> 200 m). Many species are regularly caught in commercial fisheries worldwide but their low productivity and correspondingly low intrinsic rebound potentials make them particularly vulnerable to population depletion and overexploitation. of special concern to fisheries management and conservation efforts are the spiny dogfish Squalus acanthias, the leafscale gulper shark Centrophorus squamosus and the Portuguese dogfish Centroscymnus coelolepis. These taxa have recently been declared overfished in several parts of each species' distribution but management efforts have been made to recover the "stocks" without a good understanding of the …
Molecular Genetic Studies Of Hematodinium Sp., A Parasitic Dinoflagellate Of The Blue Crab, Callinectes Sapidus, Katrina M. Pagenkopp Lohan
Molecular Genetic Studies Of Hematodinium Sp., A Parasitic Dinoflagellate Of The Blue Crab, Callinectes Sapidus, Katrina M. Pagenkopp Lohan
Dissertations, Theses, and Masters Projects
Economically viable fisheries for the American blue crab, Callinectes sapidus, occur in the USA from Delaware Bay to the Gulf of Mexico. Unfortunately, a number of factors, including overexploitation, degraded habitats, and disease, have contributed to the decline of blue crab populations in the USA. In April 2008, the Secretary of Commerce declared the blue crab fishery in the Chesapeake Bay a "commercial fishery disaster." One factor potentially contributing to the decline of blue crab populations in high salinity waters is infection with Hematodinium sp., a parasitic dinoflagellate, which can cause significant mortalities in blue crab populations. Since the first …
Genetic Diversity Of The Pathogen Streptococcus Parauberis Isolated From Bovine And Piscine Hosts, Stephen Douglas Cole
Genetic Diversity Of The Pathogen Streptococcus Parauberis Isolated From Bovine And Piscine Hosts, Stephen Douglas Cole
Dissertations, Theses, and Masters Projects
No abstract provided.
Searching For The Seed Plant Ethylene Pathway In A Basal Plant Lineage: A Genomic Approach, Ashley R. Decarme
Searching For The Seed Plant Ethylene Pathway In A Basal Plant Lineage: A Genomic Approach, Ashley R. Decarme
Dissertations, Theses, and Masters Projects
No abstract provided.
Female Plumage Coloration In Eastern Bluebirds, Sialia Sialis: Is It A Sexually Selected Trait?, Joanna Kay Hubbard
Female Plumage Coloration In Eastern Bluebirds, Sialia Sialis: Is It A Sexually Selected Trait?, Joanna Kay Hubbard
Dissertations, Theses, and Masters Projects
No abstract provided.
Understanding The Reproductive Behavior And Population Condition Of The Sandbar Shark (Carcharhinus Plumbeus) In The Western North Atlantic: A Molecular Approach To Conservation And Management, David S. Portnoy
Dissertations, Theses, and Masters Projects
The sandbar shark, Carcharhinus plumbeus, has a discontinuous cosmopolitan distribution and is exploited throughout much of its range. In the western North Atlantic, it constitutes the majority of the directed commercial fishery. The stock has declined greatly since the fisheries' inception and has not shown signs of recovery despite the implementation of management practices. Like many highly vagile marine species, it is difficult to obtain information about the sandbar shark through direct observation. Therefore, the goal of this dissertation is to use a molecular approach to examine aspects of behavior and reproduction, providing information useful in conservation and management. to …
Monograph Of The North American Freshwater Fish Leeches (Oligochaeta: Hirudinida ; Piscicolidae) And Molecular Phylogeny Of The Family Piscicolidae, Julianne I. Williams
Monograph Of The North American Freshwater Fish Leeches (Oligochaeta: Hirudinida ; Piscicolidae) And Molecular Phylogeny Of The Family Piscicolidae, Julianne I. Williams
Dissertations, Theses, and Masters Projects
The phylogeny of the Piscicolidae was analyzed from combined sequence data of 18S rDNA, cytochrome c oxidase subunit I (CO-I), nicotinamide adenine dinucleotide dehydrogenase subunit I (ND-I), and morphological data using parsimony. A worldwide distribution of Pisciolidae was represented for the first time in a phylogenetic analysis. While the family Piscicolidae was supported as a monophyletic group, the traditional subfamilies based on morphology were not supported. The Platybdellinae was polyphyletic and formed four distinct clades, and Bathybdella sawyeri did not group with any other platybdellids. The Piscicolinae was also polyphyletic, also forming four distinct clades. The pontobdellid genus Stibarobdella was …
Characterization Of Exotic Pathogens Associated With The Suminoe Oyster, Crassostrea Ariakensis, Jessica A. Moss
Characterization Of Exotic Pathogens Associated With The Suminoe Oyster, Crassostrea Ariakensis, Jessica A. Moss
Dissertations, Theses, and Masters Projects
The eastern oyster, Crassostrea virginica, once an integral part of the ecology and economy of Chesapeake Bay, has been severely depleted. Factors leading to the decline of the eastern oyster include over-harvesting, environmental degradation and disease pressure caused by the protozoans Haplosporidium nelsoni and Perkinsus marinus, known commonly as MSX and Dermo, respectively. Studies regarding the feasibility of introducing a nonnative oyster to the Bay were initiated, and field-based research on an Asian oyster, Crassostrea ariakensis, suggested that it might be a viable species for introduction. Research surrounding the proposed introduction has focused on recommendations such as those from the …
Population Genetic Structure Of Escolar (Lepidocybium Flavobrunneum) And A Molecular Phylogeny Of The Trichiuroidea, Kirsten Brendtro
Population Genetic Structure Of Escolar (Lepidocybium Flavobrunneum) And A Molecular Phylogeny Of The Trichiuroidea, Kirsten Brendtro
Dissertations, Theses, and Masters Projects
No abstract provided.
A Genetic Analysis Of The Intraspecific Relationships Of Tropical Marine Shorefishes Common To Bermuda And The Southeastern Atlantic Coast Of The United States, Kelly R. Johnson
A Genetic Analysis Of The Intraspecific Relationships Of Tropical Marine Shorefishes Common To Bermuda And The Southeastern Atlantic Coast Of The United States, Kelly R. Johnson
Dissertations, Theses, and Masters Projects
No abstract provided.
Genetic Variation Within And Among The Suminoe Oyster (Crassostrea Ariakensis) Populations And Stocks As Assessed By Molecular Markers, Qian Zhang
Dissertations, Theses, and Masters Projects
No abstract provided.
A Genetic Investigation Of Population Structure And Phylogenetics Of The Benthic Polychaete Paraprionospio Pinnata In Chesapeake Bay, Julie Beck Stubbs
A Genetic Investigation Of Population Structure And Phylogenetics Of The Benthic Polychaete Paraprionospio Pinnata In Chesapeake Bay, Julie Beck Stubbs
Dissertations, Theses, and Masters Projects
No abstract provided.
Molecular And Morphological Evolution Of The Amphipod Radiation Of Lake Baikal, Kenneth S. Macdonald Iii
Molecular And Morphological Evolution Of The Amphipod Radiation Of Lake Baikal, Kenneth S. Macdonald Iii
Dissertations, Theses, and Masters Projects
The amphipods of Lake Baikal, Russia, are a taxonomically and morphologically diverse group, and have been cited as a classic example of adaptive radiation. An unfortunate consequence of this diversity has been an instability of Baikal amphipod classification, with frequent revisions spurred by differing opinions about the phylogenetic utility of different characters. Classifications have never been based on a rigorous phylogenetic analysis of morphological data and only recently has the phylogeny of Lake Baikal's amphipods been examined using molecular tools. Unfortunately, most of these studies have led to a limited expansion of our understanding of Baikal amphipod systematics. Phylogenetic relationships …
Genetic Stock Structure Of The Sailfish, Istiophorus Platypterus, Based On Nuclear And Mitochondrial Dna, Jan Renee Mcdowell
Genetic Stock Structure Of The Sailfish, Istiophorus Platypterus, Based On Nuclear And Mitochondrial Dna, Jan Renee Mcdowell
Dissertations, Theses, and Masters Projects
The results of life history studies involving the sailfish, Istiophorus platypterus, from the Atlantic, Pacific, and Indian oceans were reviewed. Results of studies agree on several aspects of sailfish biology; sailfish exhibit opportunistic feeding behavior, follow the 28??C isotherm, spawn in summer mature at approximately age 3, and are the least migratory of the billfishes. However, results are in conflict concerning sex ratio and whether sailfish are single or multiple spawners. Although many researchers have reported that sailfish are sexually dimorphic, their fragile otoliths make them difficult to age, aging studies have not been validated, and sexual dimorphism has not …
Genetic Investigation Of Interspecific And Intraspecific Relationships Within The Genus Rapana, Arminda L. Gensler
Genetic Investigation Of Interspecific And Intraspecific Relationships Within The Genus Rapana, Arminda L. Gensler
Dissertations, Theses, and Masters Projects
No abstract provided.
Application Of Genetic Markers To Provide Species Identification And Define Stock Structure: Analyses Of Selected Marine Fishes Of The Mid -Atlantic Bight, Jan F. Cordes
Dissertations, Theses, and Masters Projects
Molecular markers and techniques were employed to develop a genetic key for the forensic identification of 16 species of Chesapeake Bay sportfishes and to investigate the stock structure of one of those species, the weakfish Cynoscion regalis. Regions within the ATP synthetase 6 (ATPase 6), Cytochrome b , cytochrome c oxidase I, NADH dehydrogenase 4 (ND4), and 12S/16S ribosomal RNA mitochondrial genes were amplified using the polymerase chain reaction (PCR) and digested with a bank of restriction endonucleases to find a genetic marker that exhibited complete interspecific differentiation and low intraspecific variation. Complete separation of all sixteen species was accomplished …
A Molecular Phylogeny Of The Sparidae (Perciformes: Percoidei), Thomas M. Orrell
A Molecular Phylogeny Of The Sparidae (Perciformes: Percoidei), Thomas M. Orrell
Dissertations, Theses, and Masters Projects
The Sparidae are a diverse group of over 110 marine species whose putative six subfamilies have been defined primarily on the basis of dentition and feeding type. Monophyly of the subfamilies has not been tested, nor have the phylogenetic relationships of all sparid genera been hypothesized. I used mitochondrial DNA sequences from the complete cytochrome b gene (1140 bp) and the partial 16S gene (621 bp) in independent and combined analyses to test the monophyly of the Sparidae, elucidate the inter-relationships of the 33 recognized genera of the Sparidae, test the validity of the six subfamilies of the Sparidae, and …
Comparative Evolution Of Molecular Markers: An Analysis Of Genetic Variation Within The Blue Marlin (Makaira Nigricans), Vincent Patrick Buonaccorsi
Comparative Evolution Of Molecular Markers: An Analysis Of Genetic Variation Within The Blue Marlin (Makaira Nigricans), Vincent Patrick Buonaccorsi
Dissertations, Theses, and Masters Projects
Blue marlin diversity was assessed at mtDNA, scnDNA, microsatellite DNA, and allozyme molecular markers. Hierarchical analysis of molecular variance (AMOVA) revealed that most genetic variation was maintained within populations, with a non-significant fraction attributable to variation among temporal replicates and between locations within oceans. In contrast, inter-ocean divergence was highly significant for a majority of loci within each marker class. Previous studies of mitochondrial DNA (mtDNA; n = 104) genetic variation within the blue marlin revealed two distinct clades of haplotypes, one of which was present only in the Atlantic (the 'Atlantic clade'), at a frequency of 40% &(F\sb{lcub}st{rcub}& = …
Phenotypic Clines In The Intertidal Snail Littorina Obtusata: The Role Of Water Temperature And Predator Effluent As Inducers Of Phenotypic Plasticity And Associated Trade-Offs In Shell Form, Geoffrey Clayton Trussell
Phenotypic Clines In The Intertidal Snail Littorina Obtusata: The Role Of Water Temperature And Predator Effluent As Inducers Of Phenotypic Plasticity And Associated Trade-Offs In Shell Form, Geoffrey Clayton Trussell
Dissertations, Theses, and Masters Projects
I examined variability in the shell form of 25 Littorina obtusata populations from Massachusetts to northern Maine. I chose this scale because the history of one of L. obtusata's principal predators, the crab Carcinus maenas, has changed dramatically in the past 100 years. Before 1900, Carcinus did not occur north of Cape Cod, Massachusetts, but by 1950 it had reached Canadian border. Moreover, in summer water temperatures during average 6-8&\sp\circ&C colder at northern locations. Shell thickness and mass increased and body mass decreased with increasing latitude. to test whether these patterns reflect plasticity in response to predators, snails from two …
Biogeography Of Amphi-Atlantic And Amphi-American Fishes: The Scomberomorus Regalis (Scombridae), Strongylura Marina (Belonidae) And Hyporhamphus Unifasciatus (Hemiramphidae) Species Groups, Heidi M. Banford
Dissertations, Theses, and Masters Projects
Phylogenetic and historical biogeographic hypotheses were explored for three groups of teleost fishes that are hypothesized to share a common biogeographic track. Distributed across the eastern Pacific/eastern Atlantic (EP/EA) biogeographic track of Rosen (1975) are the Scomberomorus regalis (Scombridae), Strongylura marina (Belonidae) and Hyporhamphus unifasciatus (Hemiramphidae) species groups comprised of one eastern Atlantic; three, three and four western Atlantic; and two, two and four eastern Pacific species, respectively, for each group. In addition, two species in the Strongylura marina and Hyporhamphus unifasciatus groups, have invaded freshwater drainages of Central and South America. Each of the three species groups were found …