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- Aquatic Health Sciences Peer-Reviewed Articles (15)
- Biological Sciences Peer-Reviewed Articles (7)
- Fisheries Science Peer-Reviewed Articles (7)
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- Bivalve molluscs (2)
- Aggregative response (1)
- Allee effect; positive density dependence; inverse density dependence; depensation; functional maturity; queen conch (1)
- Allee effects; positive density dependence; inverse density dependence; depensation (1)
- Antibody-Secreting Cells; Carp Cyprinus-carpio; Rainbow-Trout; Oncorhynchus-mykiss; Bone-Marrow; Humoral Immunity (1)
- Bonamia (1)
- Capacity (1)
- Carrying capacity (1)
- Chesapeake Bay; Crassostrea Virginica; Restoration (1)
- Community Structure; Subtropical Gyre; Cyanobacterium Prochlorococcus; Leucine Incorporation (1)
- Crassostrea Virginica; Eastern Oyster; Recruitment; Survey Methods; Chesapeake Bay (1)
- Crassostrea; virginica; oysters; aquaculture; epifauna; floats (1)
- Critical thresholds (1)
- DEA (1)
- ESL Publications (1)
- Eastern Oyster; Crassostrea Virginica; Settlement; Recruitment; Climate Change; Chesapeake Bay (1)
- Eastern Shore Laboratory (ESL) (1)
- Efficiency (1)
- Environmental rehabilitation (1)
- Epizootiology (1)
- Fisheries (1)
- Functional response (1)
- In vitro culture (1)
- Inbreeding; mating system; outbreeding; reproductive assurance; seed production (1)
- Local extinc-tion (1)
Articles 1 - 30 of 33
Full-Text Articles in Life Sciences
Real-Time Pcr For Detection And Quantification Of The Protistan Parasite Perkinsus Marinus In Environmental Waters, Corinne Audemard, Kimberly S. Reece, Em Burreson
Real-Time Pcr For Detection And Quantification Of The Protistan Parasite Perkinsus Marinus In Environmental Waters, Corinne Audemard, Kimberly S. Reece, Em Burreson
VIMS Articles
The protistan parasite Perkinsus marinus is a severe pathogen of the oyster Crassostrea virginica along the east coast of the United States. Very few data have been collected, however, on the abundance of the parasite in environmental waters, limiting our understanding of P. marinus transmission dynamics. Real-time PCR assays with SybrGreen I as a label for detection were developed in this study for quantification of P. marinus in environmental waters with P. marinus species-specific primers and of Perkinsus spp. with Perkinsus genus-specific primers. Detection of DNA concentrations as low as the equivalent of 3.3 x 10(-2) cell per 10-mul reaction …
Parasitism In Species Of Bathymodiolus (Bivalvia : Mytilidae) Mussels From Deep-Sea Seep And Hydrothermal Vents, Me Ward, Jeffrey D. Shields, Cl Van Dover
Parasitism In Species Of Bathymodiolus (Bivalvia : Mytilidae) Mussels From Deep-Sea Seep And Hydrothermal Vents, Me Ward, Jeffrey D. Shields, Cl Van Dover
VIMS Articles
Bivalve species, especially mussels, are biomass dominants in many deep-sea chemosynthetic ecosystems. As in shallow-water environments, parasites are likely to be important factors in the population dynamics of bivalve communities in chemosynthetic ecosystems, but there has been little study of parasitism in deep-sea seep or vent molluscs. In this study, Parasite types, diversity, prevalence, infection density and non-infectious indicators of stress or disease as related to host age, reproductive condition, and endosymbiont density were assessed in mussels (Bathmodiolus heckerae) from 2 seep sites and mussels (B. puteoserpentis) from 2 vent sites. We identified 10 microbial or parasitic agents in histological …
Dinitrogen Fixation And Release Of Ammonium And Dissolved Organic Nitrogen By Trichodesmium Ims101, Mr Mulholland, Da Bronk, Dg Capone
Dinitrogen Fixation And Release Of Ammonium And Dissolved Organic Nitrogen By Trichodesmium Ims101, Mr Mulholland, Da Bronk, Dg Capone
VIMS Articles
Two methods used to measure dinitrogen (N-2) fixation (acetylene reduction and N-15(2) uptake) often result in different N-2 fixation rates. Part of the discrepancy may arise from the observation that Trichodesmium can release a fraction of their recently fixed N-2 as dissolved organic nitrogen (DON) and/or ammonium (NH4+). To resolve outstanding issues regarding N-2 fixation and the production of dissolved combined nitrogen (N) by Trichodesmium, we conducted a comprehensive analysis of N-2 fixation and the production of DON and NH4+ in cultures of Trichodesmium IMS101. We performed N-15(2) uptake experiments in parallel with acetylene (C2H2) reduction assays, and measured production …
Infection Dynamics Of Marteilia Refringens In Flat Oyster Ostrea Edulis And Copepod Paracartia Grani In A Claire Pond Of Marennes-Oleron Bay, Corinne Audemard, Mc Sajus, Et Al
Infection Dynamics Of Marteilia Refringens In Flat Oyster Ostrea Edulis And Copepod Paracartia Grani In A Claire Pond Of Marennes-Oleron Bay, Corinne Audemard, Mc Sajus, Et Al
VIMS Articles
The protozoan parasite Marteilia refringens has been partly responsible for the severe decrease in the production of the European flat oyster Ostrea edulis Linnaeus in France since the 1970s. The calanoid copepod Paracartia grani Sars was recently found to be a host for M refringens in French shallow-water oyster ponds ('claires'). This study reconsidered M refringens transmission dynamics in the light of this finding, taking into account not only oyster infection dynamics and environmental factors but also data concerning the copepod host. P. grani population dynamics in the claire under study revealed that this species is the dominant planktonic copepod …
Ultrastructure Of Mycobacterium Marinum Granuloma In Striped Bass Morone Saxatilis, Dt Gauthier, Wolfgang K. Vogelbein, Ca Ottinger
Ultrastructure Of Mycobacterium Marinum Granuloma In Striped Bass Morone Saxatilis, Dt Gauthier, Wolfgang K. Vogelbein, Ca Ottinger
VIMS Articles
An emerging epizootic of mycobacteriosis currently threatens striped bass Morone saxatilis populations in Chesapeake Bay, USA. Several species of mycobacteria, including Mycobacterium marinum, species resembling AT. avium, All. gordonae, M. peregrinum, M. scrofulaceum and M. terrae, and the new species M. shottsii have been isolated from diseased and healthy bass. In this study, we describe the ultrastructure of developing M. marinum granulomas in experimentally infected bass over a period of 45 wk. The primary host response to injected mycobacteria was formation of large macrophage aggregations containing phagocytosed bacilli. AT marinum were always contained within phagosomes. Close association of lysosomes with …
Allee Effects Driven By Predation, J Gascoigne, Rom Lipcius
Allee Effects Driven By Predation, J Gascoigne, Rom Lipcius
VIMS Articles
No abstract provided.
Isolation And Characterization Of Mycobacteria From Striped Bass Morone Saxatilis From The Chesapeake Bay, Mw Rhodes, H Kator, I Kaattari, D Gautier, Wolfgang K. Vogelbein, Ca Ottinger
Isolation And Characterization Of Mycobacteria From Striped Bass Morone Saxatilis From The Chesapeake Bay, Mw Rhodes, H Kator, I Kaattari, D Gautier, Wolfgang K. Vogelbein, Ca Ottinger
VIMS Articles
Mycobacteriosis in striped bass Morone saxatilis of Chesapeake Bay, USA, was first diagnosed in 1997 based on the presence of granulomatous inflammation and acid-fast bacteria in skin and spleen. To confirm histopathology, bacteriological detection and identification of mycobacteria were begun using splenic tissue from fish with and without skin ulcerations. On the basis of initial studies using a variety of selective and nonselective media, decontamination, homogenization and incubation conditions, a simple and quantitative recovery method using aseptic necropsy of splenic tissue was developed. Optimal recovery was obtained by spread-plating homogenates on Middlebrook 7H10 agar with incubation for 3 mo at …
Light Dependence Of [H-3]Leucine Incorporation In The Oligotrophic North Pacific Ocean, Mj Church, Hw Ducklow, Da Karl
Light Dependence Of [H-3]Leucine Incorporation In The Oligotrophic North Pacific Ocean, Mj Church, Hw Ducklow, Da Karl
VIMS Articles
The influence of irradiance on bacterial incorporation of [H-3] leucine was evaluated at Station ALOHA in the oligotrophic North Pacific subtropical gyre. Six experiments were conducted on three cruises to Station ALOHA to examine how [H-3]leucine incorporation varied as a function of irradiance. Two experiments were also conducted to assess the photoautotrophic response to irradiance (based on photosynthetic uptake of [C-14] bicarbonate) in both the upper and lower photic zones. Rates of [H-3]leucine incorporation responded to irradiance in a photosynthesis-like manner, increasing sharply at low light and then saturating and sometimes declining with increasing light intensity. The influence of irradiance …
Microsatellite Marker Development And Analysis In The Eastern Oyster (Crassostrea Virginica): Confirmation Of Null Alleles And Non-Mendelian Segregation Ratios, Kimberly S. Reece, Wl Ribeiro, Pm Gaffney, Ryan Carnegie, Standish K. Allen Jr.
Microsatellite Marker Development And Analysis In The Eastern Oyster (Crassostrea Virginica): Confirmation Of Null Alleles And Non-Mendelian Segregation Ratios, Kimberly S. Reece, Wl Ribeiro, Pm Gaffney, Ryan Carnegie, Standish K. Allen Jr.
VIMS Articles
Eighteen microsatellite markers were developed for the Crassostrea virginica nuclear genome, including di-, tri-, and tetranucleotide microsatellite repeat regions that included perfect, imperfect, and compound repeat sequences. A reference panel with DNA from the parents and four progeny of 10 full-sib families was used for a preliminary confirmation of polymorphism at these loci and indications of null alleles. Null alleles were discovered at three loci; in two instances, primer redesign enabled their amplification. Two to five representative alleles from each locus were sequenced to ensure that the targeted loci were amplifying. The sequence analysis revealed not only variation in the …
A New Pathogenic Virus In The Caribbean Spiny Lobster Panulirus Argus From The Florida Keys, Jeffrey D. Shields, Dc Behringer
A New Pathogenic Virus In The Caribbean Spiny Lobster Panulirus Argus From The Florida Keys, Jeffrey D. Shields, Dc Behringer
VIMS Articles
A pathogenic virus was diagnosed from juvenile Caribbean spiny lobsters Panulirus argus from the Florida Keys. Moribund lobsters had characteristically milky hemolymph that did not clot. Altered hyalinocytes and semigranulocytes, but not granulocytes, were observed with light microscopy. Infected hemocytes had emarginated, condensed chromatin, hypertrophied nuclei and faint eosinophilic Cowdry-type-A inclusions. In some cases, infected cells were observed in soft connective tissues. With electron microscopy, unenveloped, nonoccluded, icosahedral virions (182 +/- 9 nm SD) were diffusely spread around the inner periphery of the nuclear envelope. Virions also occurred in loose aggregates in the cytoplasm or were free in the hemolymph. …
Particle-Associated Flagellates: Swimming Patterns, Colonization Rates, And Grazing On Attached Bacteria, T Kiorboe, Hp Grossart, H Ploug, K Tang, B Auer
Particle-Associated Flagellates: Swimming Patterns, Colonization Rates, And Grazing On Attached Bacteria, T Kiorboe, Hp Grossart, H Ploug, K Tang, B Auer
VIMS Articles
Some pelagic flagellates colonize particles, such as marine snow, where they graze on bacteria and thus impact the dynamics of the attached microbial communities. Particle colonization is governed by motility. Swimming patterns of 2 particle-associated flagellates, Bodo designis and Spumella sp., are very different, the former swimming slowly in an erratic, random pattern, and the latter faster and along smooth helixes of variable amplitude and frequency. At spatial scales exceeding ca. 50 mum, the motility of B. designis can be described as a random walk and modeled as diffusion. Spumella sp. shows directional persistence of the helical axes up to …
Perkinsus Mediterraneus N. Sp., A Protistan Parasite Of The European Flat Oyster Ostrea Edulis From The Balearic Islands, Mediterranean Sea, Sm Casas, A Grau, K S. Reece, Et Al
Perkinsus Mediterraneus N. Sp., A Protistan Parasite Of The European Flat Oyster Ostrea Edulis From The Balearic Islands, Mediterranean Sea, Sm Casas, A Grau, K S. Reece, Et Al
VIMS Articles
A new species, Perkinsus mediterraneus, a protistan parasite of the European oyster Ostrea edulis (L.), farmed along the coast of the Balearic Islands, Mediterranean Sea, is described. Morphological examinations with light and transmission electron microscopy, DNA sequence-analysis and enlargement in Ray's fluid thioglycollate medium (RFTM) confirmed that this parasite belongs to the genus Perkinsus. Specific morphological and genetic characteristics indicated that it should be considered a new species in the genus, Sequencing of the small subunit ribosomal (ssu rRNA) gene confirmed that the parasite belongs to the genus Perkinsus, and sequences of the internal transcribed spacer (ITS) were distinct from …
Environmental Change In The Coastal Environment: Challenges For The Selection And Propagation Of Filter Feeding Species In Aquaculture, Stock Enhancement And Environmental Rehabilitation, Roger L. Mann
VIMS Articles
Selection of species for aquaculture, fishery stock enhancement and environmental rehabilitation or restoration in the coastal zone requires consideration of the fact that species have evolved over geological time whereas changes in the coastal environment have occurred predominantly over recent historical time, often with the largest changes occurring within the past decades of human activity. The evolutionary issue is particularly noted with filter feeding molluscs, where extant species supporting both major natural fisheries and aquaculture have ancient lineages and evolved in environments that may have differed considerably from the locally turbid, nutrient enriched, disturbed (through watershed change and local activity) …
Linking Watershed Loading And Basin-Level Carrying Capacity Models To Evaluate The Effects Of Land Use On Primary Production And Shellfish Aquaculture, Mark Luckenbach, Harry V. Wang
Linking Watershed Loading And Basin-Level Carrying Capacity Models To Evaluate The Effects Of Land Use On Primary Production And Shellfish Aquaculture, Mark Luckenbach, Harry V. Wang
VIMS Articles
Aquaculture production of hard clams, Mercenaria mercenaria, in the lower Chesapeake Bay, Virginia, U.S.A., has increased dramatically within the last decade. In recent years concern has been raised that some growing areas may be approaching the exploitation carrying capacity for clam production. Preliminary calculations indicate that large-scale intensive clam aquaculture may be controlling nutrient and phytoplankton dynamics in this system. To date, carrying capacity models have not been applied to this system, but we are in the process of building models for that purpose. Moreover changing land use in the watersheds surrounding the clam-producing areas raises the need for an …
Mycobacterium-Inducible Nramp In Striped Bass (Morone Saxatilis), Erin J. Burge, David T. Gauthier, Christopher A. Ottinger, Peter A. Van Veld
Mycobacterium-Inducible Nramp In Striped Bass (Morone Saxatilis), Erin J. Burge, David T. Gauthier, Christopher A. Ottinger, Peter A. Van Veld
VIMS Articles
In mammals, the natural resistance-associated macrophage protein 1 gene, Nramp1, plays a major role in resistance to mycobacterial infections. Chesapeake Bay striped bass (Morone saxatilis) is currently experiencing an epizootic of mycobacteriosis that threatens the health of this ecologically and economically important species. In the present study, we characterized an Nramp gene in this species and obtained evidence that there is induction following Mycobacterium exposure. The striped bass Nramp gene (MsNramp) and a 554-amino-acid sequence contain all the signal features of the Nramp family, including a topology of 12 transmembrane domains (TM), the transport protein-specific binding-protein-dependent transport system inner membrane …
Seed Production From The Mixed Mating System Of Chesapeake Bay (Usa) Eelgrass (Zostera Marina; Zosteraceae), Jm Rhode, Je Duffy
Seed Production From The Mixed Mating System Of Chesapeake Bay (Usa) Eelgrass (Zostera Marina; Zosteraceae), Jm Rhode, Je Duffy
VIMS Articles
In monoecious plants, gametes can be exchanged in three ways: among unrelated genets (outbreeding), with close relatives (inbreeding), or within individuals (geitonogamous selling). These different mating systems may have consequences for population demography and fitness. The experiment presented herein used artificial crosses to examine the mating system of Chesapeake Bay, Virginia, USA eelgrass (Zostera marina L; Zosteraceae), a bisexual submerged aquatic plant that can outbreed, inbreed, and self. Genetic data indicate severe heterozygosity deficiencies and patchy genotype distribution in these beds, suggesting that plants therein reproduce primarily by vegetative propagation, autogamy, or geitonogamy. To clarify eelgrass reproductive strategies, flowers from …
Organisms Associated With Oysters Cultured In Floating Systems In Virginia, Usa, Fx O'Beirn, Paige G. Ross, Mark Luckenbach
Organisms Associated With Oysters Cultured In Floating Systems In Virginia, Usa, Fx O'Beirn, Paige G. Ross, Mark Luckenbach
VIMS Articles
The number and abundance of macro-faunal taxa was estimated from six floating structures (floats) used to culture the Eastern oyster (Crassostrea virginica) near Chincoteague Island. Virginia, USA. After a 10-mo grow-out period, all organisms found among and attached to the cultured oysters were counted. The final mean size of oysters was 80.5 (14.7 SD) mm. Overall, 45 species of macrofauna were recorded with the number of species in the floats ranging from 24 to 36. There was no relationship between the number of taxa and the density of oysters in the floats. Total abundances of associated organisms were estimated at …
Conserving Populations At Low Abundance: Delayed Functional Maturity And Allee Effects In Reproductive Behaviour Of The Queen Conch Strombus Gigas, J Gascoigne, Rom Lipcius
Conserving Populations At Low Abundance: Delayed Functional Maturity And Allee Effects In Reproductive Behaviour Of The Queen Conch Strombus Gigas, J Gascoigne, Rom Lipcius
VIMS Articles
Effectiveness of conservation measures for diminished populations depends on the mechanism producing low abundance. In queen conch, which is heavily exploited, reproductive activity is depressed where conch density is low, which may be due to the Allee effect, poor habitat quality, or delayed functional maturity. To determine the mechanism underlying impaired reproduction in shallow seagrass beds, mature conch were translocated from 'source' sites with high and low, ambient conch density (similar to1000 and similar to20 conch ha(-1), respectively), and kept at high density in enclosures within high- and low-density 'host' sites. We monitored reproductive activity, and modelled conch population dynamics …
Allee Effects In Marine Systems, J Gascoigne, Rom Lipcius
Allee Effects In Marine Systems, J Gascoigne, Rom Lipcius
VIMS Articles
The fitness or population growth rate of populations with Allee effects increases with increasing population size or density up to a certain threshold. Allee effects are possible in marine populations, as they are less open than has been assumed and may have a metapopulation structure. We modelled the population consequences of Allee effects and show that increases in mortality interact with critical Allee thresholds, such that an Allee effect with no population consequences at low mortality can drive a population to extinction when mortality is increased. In heavily fished species, populations with strong Allee effects go extinct at lower levels …
Production Of Chromophoric Dissolved Organic Matter (Cdom) In The Open Ocean By Zooplankton And The Colonial Cyanobacterium Trichodesmium Spp., Deborah K. Steinberg, Nb Nelson, Ca Carlson, Ac Prusak
Production Of Chromophoric Dissolved Organic Matter (Cdom) In The Open Ocean By Zooplankton And The Colonial Cyanobacterium Trichodesmium Spp., Deborah K. Steinberg, Nb Nelson, Ca Carlson, Ac Prusak
VIMS Articles
Chromophoric (or colored) dissolved organic matter (CDOM) has been identified as a major determinant of the optical properties of oligotrophic oceans. The factors controlling distribution of CDOM far from the direct influence of land are not well known, as CDOM abundance and distribution does not directly correlate with phytoplankton productivity or biomass, or with dissolved organic matter (DOM) concentration. As part of a larger study of the dynamics of CDOM in the open ocean, we investigated direct release from plankton as a factor contributing to distribution patterns of CDOM. We measured the production of CDOM by zooplankton (copepods, euphausiids, amphipods, …
Decadal Scale Changes In Seasonal Patterns Of Oyster Recruitment In The Virginia Sub Estuaries Of The Chesapeake Bay, Melissa Southworth, Roger L. Mann
Decadal Scale Changes In Seasonal Patterns Of Oyster Recruitment In The Virginia Sub Estuaries Of The Chesapeake Bay, Melissa Southworth, Roger L. Mann
VIMS Articles
Reproductive periodicity of sessile estuarine invertebrates reflects local seasonality of environmental (temperature, salinity) and biologic (food) parameters. Estuaries are ephemeral features in geologic time but considered somewhat constant in the course of recent human history (decadal time scales). Analyses of long-term trends in eastern oyster (Crassostrea virginica) settlement periodicity since 1960 in three major Chesapeake Bay rivers (James, Piankatank and Great Wicomico Rivers) of the Chesapeake Bay show marked changes within the 4-decade time frame. The 50th percentile of cumulative recruitment occurs between day 194 and 250 of the year depending on year and location. Significant coherence in interannual variation …
Evidence Of Shark Predation And Scavenging On Fishes Equipped With Pop-Up Satellite Archival Tags, David Kerstetter, Jeffery J. Polovina, John Graves
Evidence Of Shark Predation And Scavenging On Fishes Equipped With Pop-Up Satellite Archival Tags, David Kerstetter, Jeffery J. Polovina, John Graves
VIMS Articles
No abstract provided.
Site Selection For Oyster Habitat Rehabilitation In The Virginia Portion Of The Chesapeake Bay: A Commentary, Roger L. Mann, Da Evans
Site Selection For Oyster Habitat Rehabilitation In The Virginia Portion Of The Chesapeake Bay: A Commentary, Roger L. Mann, Da Evans
VIMS Articles
A significant body of knowledge has been generated during the past decade on disease tolerance of the native oyster Crassostrea virginica. A major opportunity to move into a large-scale field application phase of that knowledge has been presented by a 10-y commitment by the U.S. Army Corps of Engineers (ACOE) to a partnership in Virginia focused on widespread restoration of oyster resources for ecological purposes. The partnership involves ACOE, the Virginia Institute of Marine Science (VIMS), the Virginia Marine Resources Commission (VMRC), and the Chesapeake Bay Foundation (CBF). This collaboration will effect a sequenced restoration effort involving site selection, site …
Plasmablast And Plasma Cell Production And Distribution In Trout Immune Tissues, E S. Bromage, I M. Kaattari, P Zwollo, S L. Kaattari
Plasmablast And Plasma Cell Production And Distribution In Trout Immune Tissues, E S. Bromage, I M. Kaattari, P Zwollo, S L. Kaattari
VIMS Articles
These studies describe the in vitro and ex vivo generation of plasmablasts and plasma cells in trout (Oncorhynchus mykiss) peripheral blood and splenic and anterior kidney tissues. Cells were derived either from naive trout and cultured with the polyclonal activator, Escherichia coli LPS, or from trout that had been immunized with trinitrophenyl-keyhole limpet hemocyanin. Hydroxyurea was used to resolve populations of replicating (plasmablast) and nonreplicating (plasma cell) Ab-secreting cells (ASC). Complete inhibition of Ig secretion was only observed within the PBL. Both anterior kidney and splenic lymphocytes possessed a subset of ASCs that were hydroxyurea resistant. Thus, in vitro production …
Microcell Parasites Of Oysters: Recent Insights And Future Trends, Ryan Carnegie, Nathalie Cochennec-Laureau
Microcell Parasites Of Oysters: Recent Insights And Future Trends, Ryan Carnegie, Nathalie Cochennec-Laureau
VIMS Articles
Our understanding of the microcell oyster parasites of the genera Bonamia and Mikrocwos has expanded 111 recent years with the application of ultrastru ctural and espec ially molecular biological research approaches. Molecular phylogenetic analyses of SSU rRNA genes have united three species, Bonamia ostreae, Bonamia exitiosa, and Mikrocytos (now Bonamia) roughleyi, in a microcell clade within the Haplosporidia, supporting both early and recent ultrastructural observations. Ult rastructural and molecular phylogenetic ev idence has emerged that Mikrocytos mackini, on the other hand, is a unique proti st with unusual adaptations for a parasitic existence. DNA probes and polymerase chain reaction (PCR) …
Perkinsosis In Molluscs: A Review, Antonio Villalba, Kimberly S. Reece, M. Camino Ordas, Sandra M. Casas, Antonio Figueras
Perkinsosis In Molluscs: A Review, Antonio Villalba, Kimberly S. Reece, M. Camino Ordas, Sandra M. Casas, Antonio Figueras
VIMS Articles
The genus Perkinsus includes protistan parasites infecting marine molluscs throughout the world, some of which are associated with mass mortalities. Life cycle involves vegetative proliferation within the host, by which a cell named trophozoite undergoes successive bipartitioning. Other stages have been observed in vitro or in vivo, depending on the species: hypnospore, zoosporangium and zoospore. Molecular taxonomy supports a close affinity between dinoflagellates and Perkinsus spp. Six species of Perkinsus are currently considered valid: P. marinus, P. olseni, P. qugwadi, P. chesapeaki, P. andrewsi and P. mediterraneus. Histology and, above all, incubation of host tissues in Ray’s fluid thioglycollate medium …
Deterministic And Stochastic Capacity Estimation For Fishery Capacity Reduction, James Kirkley, Catherine Morrison Paul, Dales Squires
Deterministic And Stochastic Capacity Estimation For Fishery Capacity Reduction, James Kirkley, Catherine Morrison Paul, Dales Squires
VIMS Articles
Deterministic data envelopment analysis (DEA) and stochastic pro- duction frontier (SPF) models are alternative methods for estimating capacity in fisheries. Fishery managers should be aware of likely differences in the capacity estimates obtained from these approaches if such estimates are to be used to support capacity reduction programs. In this paper, we provide a comparative analysis of DEA and SPF capacity estimates for a variety of possible capacity concepts using a panel data set for 10 vessels in the U.S. Northwest Atlantic scallop fishery. We find that DEA capacity output measures are higher than cor- responding SPF measures, but that …
Short-Run Welfare Losses From Essential Fish Habitat Designations For The Surfclam And Ocean Quahog Fisheries, Robert L. Hicks, James Kirkley, Iver E. Strand Jr.
Short-Run Welfare Losses From Essential Fish Habitat Designations For The Surfclam And Ocean Quahog Fisheries, Robert L. Hicks, James Kirkley, Iver E. Strand Jr.
VIMS Articles
In this paper, we present a spatial model of fishing that can be used to assess some of the economic welfare losses to producers from setting aside essential fish habitat (EFH) areas. The paper demonstrates how spatially explicit behavioral models of fishing are estimated, how these models can be used to measure welfare losses to fishermen, and how these models can then, in turn, be used to simulate fishing behavior. In developing the spatial model of fishing behavior, the work incorporates ideas of congestion and information effects, and we show a modification of standard welfare measures that accounts for these …
A Review Of Recent Information On The Haplosporidia, With Special Reference To Haplosporidium Nelsoni (Msx Disease), E M. Burreson, S E. Ford
A Review Of Recent Information On The Haplosporidia, With Special Reference To Haplosporidium Nelsoni (Msx Disease), E M. Burreson, S E. Ford
VIMS Articles
The current status of the Haplosporidia is reviewed as well as recent information on Haplosporidium nelsoni, the causative agent of MSX disease in oysters. Recent molecular phylogenetic analyses with greatly increased taxon sampling support monophyly of the Haplosporidia and hypothesize placement of the group as sister taxon to the phylum Cercozoa. Oyster pathogens in the genus Bonamia should be considered haplosporidians based on molecular sequence data. Thus, the group contains 4 genera: Uropsoridium, Haplosporidium, Bonamia and Minchinia. Molecular phylogenetic analyses support monophyly of Urosporidium, Bonamia and Minchinia, but Haplosporidium forms a paraphyletic clade. Reports of haplosporidia worldwide are reviewed. Molecular …
Supplementation Of Perkinsus Marinus Cultures With Host Plasma Or Tissue Homogenate Enhances Their Infectivity, Cg Earnhart, M. A. Vogelbein, Gd Brown, Ks Reece, Sl Kaattari
Supplementation Of Perkinsus Marinus Cultures With Host Plasma Or Tissue Homogenate Enhances Their Infectivity, Cg Earnhart, M. A. Vogelbein, Gd Brown, Ks Reece, Sl Kaattari
VIMS Articles
The protozoan oyster parasite Perkinsus marinas can be cultured in vitro in a variety of media; however, this has been associated with a rapid attenuation of infectivity. Supplementation of defined media with products of P. marinus-susceptible (Crassostrea virginica) and -tolerant (Crassostrea gigas, Crassostrea ariakensis) oysters alters proliferation and protease expression profiles and induces differentiation into morphological forms typically seen in vivo. It was not known if attenuation could be reversed by host extract supplementation. To investigate correlations among these changes as well as their association with infectivity, the effects of medium supplementation with tissue homogenates from both susceptible and tolerant …