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VIMS Articles

1996

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Articles 1 - 30 of 31

Full-Text Articles in Life Sciences

Density-Dependent Settler-Recruit-Juvenile Relationships In Blue Crabs, Aj Pile, Rom Lipcius, J Van Montfrans, R J. Orth Aug 1996

Density-Dependent Settler-Recruit-Juvenile Relationships In Blue Crabs, Aj Pile, Rom Lipcius, J Van Montfrans, R J. Orth

VIMS Articles

Current theory on the population dynamics of marine species with complex life history patterns posits that a suite of physical and biotic forces (e.g., habitat structure and density-dependent predation or emigration) control survival and abundance in early life history, particularly after settlement. We have conducted a long-term sampling effort accompanied by a series of field and laboratory experiments examining the joint effects of habitat type, body size, and population density upon abundance and survival of early juveniles of the blue crab, Callinectes sapidus. In addition, the chance occurrence of a tropical storm during one set of experiments provided an ...


Simulation Of Annual Plankton Productivity Cycle In The Black Sea By A One-Dimensional Physical-Biological Model, Temel Oguz, Hugh Ducklow, Paola Malanotte-Rizzoli, Nikolai P. Nezlin, Umit Unluata Jul 1996

Simulation Of Annual Plankton Productivity Cycle In The Black Sea By A One-Dimensional Physical-Biological Model, Temel Oguz, Hugh Ducklow, Paola Malanotte-Rizzoli, Nikolai P. Nezlin, Umit Unluata

VIMS Articles

The annual cycle of the plankton dynamics in the central Black Sea is studied by a one-dimensional vertically resolved physical-biological upper ocean model, coupled with the Mellor-Yamada level 2.5 turbulence closure scheme. The biological model involves interactions between the inorganic nitrogen (nitrate, ammonium), phytoplankton and herbivorous zooplankton biomasses, and detritus. Given a knowledge of physical forcing, the model simulates main observed seasonal and vertical characteristic features, in particular, formation of the cold intermediate water mass and yearly evolution of the upper layer stratification, the annual cycle of production with the fall and the spring blooms, and the subsurface phytoplankton ...


Histopathology Of The Thymus Of Coho Salmon Oncorhynchus Kisutch Experimentally Infected With Renibacterium Salmoninarum, E Flano, Sl Kaattari, B Razquin, Aj Villena Jul 1996

Histopathology Of The Thymus Of Coho Salmon Oncorhynchus Kisutch Experimentally Infected With Renibacterium Salmoninarum, E Flano, Sl Kaattari, B Razquin, Aj Villena

VIMS Articles

We report on the histopathological changes occurring in the thymus of coho salmon Oncorhynchus kisutch experimentally infected with Renibacterium salmoninarum. Coho salmon were intraperitoneally infected, and the thymi were collected weekly from 1 to 7 wk post-infection, and processed for ultrastructural study. The thymus appeared to be infected only in fish collected at 6 and 7 wk post-infection. The first stage of the infection was characterized by the presence of a low number of bacteria scattered in the connective tissue of the capsule. Further progression of the thymic infection was characterized by the rupture of the capsular-thymic barrier, and by ...


Concentrations And Uptake Of Neutral Monosaccharides Along 14°W In The Equatorial Pacific: Contribution Of Glucose To Heterotrophic Bacterial Activity And The Dom Flux, James Rich, Hugh Ducklow, David L. Kirchman Jun 1996

Concentrations And Uptake Of Neutral Monosaccharides Along 14°W In The Equatorial Pacific: Contribution Of Glucose To Heterotrophic Bacterial Activity And The Dom Flux, James Rich, Hugh Ducklow, David L. Kirchman

VIMS Articles

We examined concentrations and uptake of dissolved neutral monosaccharides (DNMS) in order to determine the contribution of DNMS to heterotrophic bacterial production and to the flux of dissolved organic matler (DOM) in the equatorial Pacific. DNMS concentrations were greater during El Niño‐affected months of February–April 1992 than during August–October 1992; in contrast, glucose turnover was the opposite— turnover was faster in August–October than in February–April. The variation in sugar concentrations and turnover probably resulted from El Niño‐induced changes in primary production; as El Niño waned primary production increased, which appeared to stimulate bacterial activity ...


An Unidentified Haplosporidian Parasite Of Bay Scallop Argopecten Irradians Cultured In The Shandong And Liaoning Provinces Of China, Fle Chu, Em Burreson, F Zhang, K Chew May 1996

An Unidentified Haplosporidian Parasite Of Bay Scallop Argopecten Irradians Cultured In The Shandong And Liaoning Provinces Of China, Fle Chu, Em Burreson, F Zhang, K Chew

VIMS Articles

Since 1988 growers of bay scallop Argopecten irradians in China have been experiencing mortality in their cultured stocks. Although poorly documented, mortality apparently began near Qingdao and has since spread to other areas of Shandong and Liaoning provinces. Samples of cultured scallops were collected from several growing areas in these provinces and analyzed by histological methods for pathogens. An unidentified haplosporidian parasite was observed in a high proportion of scallops from two of the stocks examined. Most infections were of low intensity, but one heavy infection was also observed. Only plasmodia stages were observed; they occurred intercellularly in connective tissues ...


Effects Of Sunlight On Bacteriophage Viability And Structure, Ke Wommack, Rt Hill, Ta Muller, Rr Colwell Apr 1996

Effects Of Sunlight On Bacteriophage Viability And Structure, Ke Wommack, Rt Hill, Ta Muller, Rr Colwell

VIMS Articles

Current estimates of viral abundance in natural waters rely on direct counts of virus-like particles (VLPs), using either transmission or epifluorescence microscopy. Direct counts of VLPs, while useful in studies of viral ecology, do not indicate whether the observed VLPs are capable of infection and/or replication. Rapid decay in bacteriophage viability under environmental conditions has been observed. However, it has not been firmly established whether there is a corresponding degradation of the virus particles, To address this question, viable and direct counts were carried out employing two Chesapeake Bay bacteriophages in experimental microcosms incubated for 56 h at two ...


Enhanced Immunogenicity Of Renibacterium Salmoninarum In Chinook Salmon After Removal Of The Bacterial Cell Surface-Associated 57 Kda Protein, Pa Wood, Sl Kaattari Apr 1996

Enhanced Immunogenicity Of Renibacterium Salmoninarum In Chinook Salmon After Removal Of The Bacterial Cell Surface-Associated 57 Kda Protein, Pa Wood, Sl Kaattari

VIMS Articles

A study was conducted to determine the effect of endogenous serine protease activity on the immunogenicity of Renibacterium salmoninarum cells in chinook salmon Oncorhynchus tshawytscha. Salmon were immunized with either R. salmoninarum cells possessing p57 (p57(+)) or substantially depleted of p57 (p57(-)). The resultant antisera were examined by whole cell ELISA and immunoblot procedures using p57(+), p57(-), proteinase-K-treated, and periodate-treated whole cells. These analyses revealed that the removal of p57 by the endogenous serine protease significantly enhanced the immunogenicity of the cell, resulting in a 20-fold increase in detectable antibody titers. The bulk of this antibody activity was directed at ...


Histopathology Of The Renal And Splenic Haemopoietic Tissues Of Coho Salmon Oncorhynchus Kisutch Experimentally Infected With Renibacterium Salmoninarum, E Flano, P Lopez-Fierro, B Razquin, S Kaattari, A Villena Feb 1996

Histopathology Of The Renal And Splenic Haemopoietic Tissues Of Coho Salmon Oncorhynchus Kisutch Experimentally Infected With Renibacterium Salmoninarum, E Flano, P Lopez-Fierro, B Razquin, S Kaattari, A Villena

VIMS Articles

We report the histopathological changes occurring in the renal and splenic haemopoietic tissues of coho salmon Oncorhynchus kisutch experimentally infected with renibacterium salmoninarum. In both tissues we were able by light microscopy to distinguish 3 different grades in the progression of the infection. The grades of infection were characterized according to the location of the bacteria and the tissue injuries. Ultrastructural observation revealed sinusoidal cells, macrophages, reticular and barrier cells to be infected by the pathogen, and necrosis of the tissue to be general in advanced stages of the infection. Despite destruction of the haemopoietic tissue, plasmacytopoietic foci were frequently ...


Species Boundaries, Specialization, And The Radiation Of Sponge-Dwelling Alpheid Shrimp, J Duffy Jan 1996

Species Boundaries, Specialization, And The Radiation Of Sponge-Dwelling Alpheid Shrimp, J Duffy

VIMS Articles

Microevolutionary studies and natural history suggest that host-specialization has promoted the high diversity of tropical sponge-dwelling snapping shrimps (Decapoda, Alpheidae, Synalpheus). Yet the taxonomic difficulty of this genus has precluded rigorous tests of this hypothesis. S. rathbunae Coutiere is among the most abundant invertebrates inhabiting the framework of sponges and dead coral that forms the floor of Caribbean coral reefs. Even within a small area S. rathbunae exhibits the apparently wide variation in size, color, and morphology that has long frustrated efforts to identify and define species boundaries within this large (> 100 described species) genus. Here I show that sympatric ...


A Retrospective Time Series Analysis Of Oyster, Crassostrea Virginica, Recruitment (1946-1993), Herbert Austin, David Evans, Dexter Haven Jan 1996

A Retrospective Time Series Analysis Of Oyster, Crassostrea Virginica, Recruitment (1946-1993), Herbert Austin, David Evans, Dexter Haven

VIMS Articles

Temporal patterns of eastern oyster, Crassostrea virginica (Gmelin 1791), spatfall in the Virginia tributary rivers to the Chesapeake Bay showed a decline in all rivers from 1946 through the early 1970s, with a subsequent leveling off. The decline was most severe in the James and less so moving north to the York and Rappahannock Rivers; it was least severe in the Potomac River. Yearling patterns generally mirrored the spat. Cluster analyses grouped the bars naturally by up- and downriver spatfall patterns. They also clustered this way when between-river comparisons were made. Spatfall showed a significant cross-correlation with yearlings a year ...


A Comparison Of Crassostrea Gigas And Crassostrea Virginica: Effects Of Temperature And Salinity On Susceptibility To The Protozoan Parasite, Perkinsus Marinus, Fu-Lin C. Chu, Aswani Volety, G Constantin Jan 1996

A Comparison Of Crassostrea Gigas And Crassostrea Virginica: Effects Of Temperature And Salinity On Susceptibility To The Protozoan Parasite, Perkinsus Marinus, Fu-Lin C. Chu, Aswani Volety, G Constantin

VIMS Articles

The susceptibility of diploid and triploid (2N and 3N) Crassostrea gigas to Perkinsus marinus was compared, in the laboratory, with that of Crassostrea virginica al three test temperatures (10, 15, and 25 degrees C) at 20-22 ppt and at three test salinities (3, 10, and 20 ppt) at a temperature of 19-22 degrees C. Experimental oysters were challenged twice with freshly isolated P, marinus meronts, after acclimation to test temperatures and salinities. Although infection prevalence and intensity increased with temperature (p = 0.0001) and salinity in P. marinus-challenged oysters of both oyster species: they were highest in C. virginica groups ...


History Of Perkinsus Marinus, A Pathogen Of Oysters In Chesapeake Bay 1950-1984, Jd Andrews Jan 1996

History Of Perkinsus Marinus, A Pathogen Of Oysters In Chesapeake Bay 1950-1984, Jd Andrews

VIMS Articles

The pathogen Perkinsus marinus (Dermo) was discovered in Chesapeake Bay in 1950. It was already widely distributed in the Bay and caused annual mortality below the mouth of the Rappahannock River. Annual mortality in trayed oysters at the Virginia Institute of Marine Science (VIMS) varied annually from 24% to 57% at this most favorable site for the disease. Over 2 million bushels of seed oysters from the James River public beds were transplanted annually to private beds in 4 major growing areas. These were Hampton Roads, lower Bay proper, Mobjack Bay at mouth of York River, and the Rappahannock River ...


Laboratory Investigations Of Susceptibility, Infectivity, And Transmission Of Perkinsus Marinus In Oysters, Fu-Lin C. Chu Jan 1996

Laboratory Investigations Of Susceptibility, Infectivity, And Transmission Of Perkinsus Marinus In Oysters, Fu-Lin C. Chu

VIMS Articles

The protozoan parasite, Perkinsus marinus (Dermo), has caused significant mortality in the eastern oyster, Crassostrea virginica, along the east coast of the United States and the Gulf of Mexico, since the 1950s. Because of its current expanded distribution and increased abundance, P. marinus is now considered more prevalent in the mid-Atlantic waters and the Chesapeake Bay in particular, than another protozoan pathogen, Haplosporidium nelsoni (MSX). The susceptibility, infectivity/pathogenicity, and transmission of P. marinus in eastern oysters were investigated in numerous laboratory studies, The influence of environmental factors such as temperature, salinity, and pollution on the interaction between the host ...


Propagation And In Vitro Studies Of Perkinsus Marinus, Jerome F. Lapeyre Jan 1996

Propagation And In Vitro Studies Of Perkinsus Marinus, Jerome F. Lapeyre

VIMS Articles

The development of continuous cultures of Perkinsus marinus (Apicomplexa) is a major breakthrough that will lead to a better understanding of this deadly oyster pathogen. More than 10 P. marinus isolates are currently in continuous cultures. Culture media used to propagate P. marinus range from media designed for the culture of mammalian cells to protein-free chemically defined media. Continuous cultures of P. marinus can be initiated from a variety of infected oyster tissues or from isolated hypnospores (i.e., the enlarged stage of P. marinus from oyster tissue incubated in Ray's fluid thioglycollate medium). P. marinus cells adapt well ...


Mitochondrial Dna Diversity And Divergence Among Sharpnose Sharks, Rhizoprionodon Terraenovae, From The Gulf Of Mexico And Mid-Atlantic Bight, Edward J. Heist, John Musick, John Graves Jan 1996

Mitochondrial Dna Diversity And Divergence Among Sharpnose Sharks, Rhizoprionodon Terraenovae, From The Gulf Of Mexico And Mid-Atlantic Bight, Edward J. Heist, John Musick, John Graves

VIMS Articles

The Atlantic sharpnose shark, Rhizoprionodon terraenovae, is a small coastal shark that is harvested in both directed and nondirected fisheries throughout its range. Because pups of this species are found both along the southeastern U.S. Atlantic coast and the Gulf of Mexico, it is possible that multiple isolated breeding stocks exist. Restriction fragment length polymorphism analysis of mitochondrial DNA was used to test the hypothesis that Atlantic sharpnose sharks from the U.S. Atlantic coast and the western Gulf of Mexico have identical mitochondrial haplotype frequencies and therefore no apparent genetic stock structure. Seven mitochondrial haplotypes were detected among ...


Characterization Of Soft-Bottom Benthic Habitats Of The Aland Islands, Northern Baltic Sea, E Bonsdorff, Rj Diaz, R Rosenberg, A Norkko Jan 1996

Characterization Of Soft-Bottom Benthic Habitats Of The Aland Islands, Northern Baltic Sea, E Bonsdorff, Rj Diaz, R Rosenberg, A Norkko

VIMS Articles

Sediment surface and profile imaging (SPI) was used in combination with grab sampling of sediment (sediment type, organic content, benthic infauna) and hydrography (temperature, oxygen saturation of bottom water) to analyze and describe the soft-bottom benthic habitats of the Aland archipelago (60 degrees 00' to 60 degrees 30' N, 19 degrees 30' to 20 degrees 30' E) in the northern Baltic Sea. The SPI analysis covered 42 stations (5 to 263 m depth), from inner sheltered bays to open coastal waters, with varying sediment types (soft mud with high organic content to sandy substrates with low organic content; loss on ...


In Situ Grazing On Plankton <10 Mu M By The Boreal Sponge Mycale Lingua, Aj Pile, Mr Patterson, Jd Witman Jan 1996

In Situ Grazing On Plankton <10 Mu M By The Boreal Sponge Mycale Lingua, Aj Pile, Mr Patterson, Jd Witman

VIMS Articles

Ultraplankton, heterotrophic and autotrophic plankton < 5 mu m, are the most abundant food source in the world's oceans, yet their role as a food source for macroinvertebrates is largely unexamined. We quantified in situ feeding on heterotrophic and autotrophic plankton < 10 mu m by the boreal sponge Mycale lingua using measurements that quantified sponge feeding efficiencies, pumping rates, and abundance to determine the contribution of plankton < 10 mu m to sponge carbon intake. Using dual-beam now cytometry we identified 5 populations of plankton < 10 mu m: heterotrophic bacteria, Prochlorococcus, Synechococcus-type cyanobacteria, autotrophic eucaryotes < 3 mu m, and autotrophic eucaryotes 3 to 10 mu m Mycale lingua nonselectively grazed on all types of plankton < 10 mu m. Prochlorococcus was filtered with the highest efficiency (93%), followed by Synechococcus-type cyanobacteria (89%), autotrophic eucaryotes 3 to 10 mu m (86%), heterotrophic bacteria (74%), and autotrophic eucaryotes < 3 mu m (72%). We conservatively estimate that M. lingua al naturally occurring densities can obtain 29 mg C d(-1) m(-2) feeding on plankton < 10 mu m, with 74% resulting from ultraplankton, suggesting that ultraplankton are an important overlooked component of benthic-pelagic coupling.


Utilization And Turnover Of Labile Dissolved Organic Matter By Bacterial Heterotrophs In Eastern North Pacific Surface Waters, J Cherrier, Je Bauer, Erm Druffel Jan 1996

Utilization And Turnover Of Labile Dissolved Organic Matter By Bacterial Heterotrophs In Eastern North Pacific Surface Waters, J Cherrier, Je Bauer, Erm Druffel

VIMS Articles

Seawater incubation experiments were conducted in June and October 1992 to examine bacterial utilization of labile dissolved organic matter (DOM) in open ocean surface waters of the eastern North Pacific. Natural plankton extract-DOM (PE-DOM) and selected model compounds were added to seawater samples to evaluate bacterial utilization and respiration rates relative to bacterial carbon production rates for the various amendments. PE-DOM always stimulated bacterial production and DOM utilization, and the primary nitrogen source supporting this bacterial production was dissolved organic nitrogen (DON). Utilization of DON during exponential growth was balanced by the production of ammonium for samples amended with PE-DOM ...


Non-Structural Carbohydrate Reserves Of Eelgrass Zostera Marina, Mk Burke, Wc Dennison, Ka Moore Jan 1996

Non-Structural Carbohydrate Reserves Of Eelgrass Zostera Marina, Mk Burke, Wc Dennison, Ka Moore

VIMS Articles

The high minimum Light requirement of eelgrass Zostera marina L. suggests that this species has difficulty in maintaining a positive carbon balance except under high light conditions. The carbon balance of Z. marina can be studied by following seasonal changes in non-structural carbohydrate (NSC) reserves, however, little is known about the seasonal variation in NSC reserves in seagrasses or the influence of shading on NSC reserve content and distribution. Seasonal changes in eelgrass NSC reserves were measured in a shallow coastal lagoon, Chincoteague Bay, Maryland/Virginia, USA, near the southern edge of this species' distributional range. Concentrations of sugar varied ...


Seasonal Variability Of Particulate Organic Radiocarbon In The Northeast Pacific Ocean, Ellen R.M. Druffel, James E. Bauer, Peter M. Williams, Shelia Griffin, David Wolgast Jan 1996

Seasonal Variability Of Particulate Organic Radiocarbon In The Northeast Pacific Ocean, Ellen R.M. Druffel, James E. Bauer, Peter M. Williams, Shelia Griffin, David Wolgast

VIMS Articles

We present Delta(14)C measurements of particulate organic carbon (POC) collected on four cruises at our time series site (station M) in the northeast Pacific Ocean. We observe a large gradient with depth in the suspended POC Delta(14)C values (124-160 parts per thousand). These profiles display lower Delta(14)C values (by 20-30 parts per thousand) in samples between 2500 m and the bottom during June 1992 and July 1993 than those during February and October 1992. Values of Delta(14)C in sinking POC from deep-moored sediment trap collections suggest a semiannual trend that displays lower ...


Stratigraphic Consistency And The Shape Of Things, Me Siddall Jan 1996

Stratigraphic Consistency And The Shape Of Things, Me Siddall

VIMS Articles

Huelsenbeck (1994) identified three unsolved issues regarding the use of temporal information in the fossil record: (1) how goodness of fit between stratigraphy and phylogeny should be determined, (2) how the significance of this fit should be determined, and (3) how those results might be employed other than for description. With respect to goodness of fit, Huelsenbeck (1994) suggested that his stratigraphic consistency index (SCI) was both intuitively simple and not subject to the biases inherent in other stratigraphic indices. With respect to these prior indices (Gauthier et ai., 1988; Norell and Novacek, 1992), apparent biases are the result of ...


Phylogenetic Covariance Probability: Confidence And Historical Associations, Me Siddall Jan 1996

Phylogenetic Covariance Probability: Confidence And Historical Associations, Me Siddall

VIMS Articles

The correlation that exists among multiple cladograms is often taken as evidence of some underlying macroevolutionary phenomenon common to the histories of those clades and, thus, as an explanation of the patterns of association of the constituent taxa. Such studies have various forms, the most common of which are cladistic biogeography and host-parasite coevolution. The issue of confidence has periodically been a theoretical consideration of vicariance biogeographers but in practice has been largely ignored by others. Previous approaches to assessing confidence in historical associations are examined here in relation to the difference between simple-event and cumulative probabilities and in relation ...


Growth Of Bacterioplankton And Consumption Of Dissolved Organic Carbon In The Sargasso Sea, C. A. Carlson, H. W. Ducklow Jan 1996

Growth Of Bacterioplankton And Consumption Of Dissolved Organic Carbon In The Sargasso Sea, C. A. Carlson, H. W. Ducklow

VIMS Articles

Lability of the bulk dissolved organic carbon (DOG) pool and the amount available to bacterioplankton on short time scales (hours to days) were examined in oligotrophic Sargasso Sea water (near Bermuda). We examined bacterial growth and DOC utilization using seawater culture methodology in combination with measurements of bacterial abundance, cell volume, and DOC. Bulk DOC concentrations were determined by high temperature combustion (HTC) analysis, which proved to be a sensitive method for detecting small changes in natural concentration of DOG. Measurable bacterial growth and DOC utilization only occurred in unamended cultures when initial DDC concentrations were greater than observed in ...


The Structure Of Perkinsus Marinus (Mackin, Owen And Collier, 1950) Levine, 1978 With Comments On Taxonomy And Phylogeny Of Perkinsus Spp., Frank O. Perkins Jan 1996

The Structure Of Perkinsus Marinus (Mackin, Owen And Collier, 1950) Levine, 1978 With Comments On Taxonomy And Phylogeny Of Perkinsus Spp., Frank O. Perkins

VIMS Articles

A description of the structure of the Crassostrea virginica pathogen Perkinsus marinus is provided from observations at the light and transmission electron microscope levels of detail and includes cellular multiplication (palintomy) in the host and zoosporulation in estuarine water as well as observations of cells in axenic culture. The description is primarily a review of previously published information; however, new information is provided on development of walled outgrowths from hypnospores derived from fluid thioglycollate medium treatment of infected host tissue. The protoplast within the outgrowths subdivides to yield small unicells which escape into the ambient water, or the protoplast emerges ...


Zostera Marina (Eelgrass) Growth And Survival Along A Gradient Of Nutrients And Turbidity In The Lower Chesapeake Bay, Ken Moore, Ha Neckles, R J. Orth Jan 1996

Zostera Marina (Eelgrass) Growth And Survival Along A Gradient Of Nutrients And Turbidity In The Lower Chesapeake Bay, Ken Moore, Ha Neckles, R J. Orth

VIMS Articles

Survival of transplanted Zostera marina L. (eelgrass), Z. marina growth, and environmental conditions were studied concurrently at a number of sites in a southwestern tributary of the Chesapeake Bay to elucidate the factors limiting macrophyte distribution in this region. Consistent differences in survival of the transplants were observed, with no long-term survival at any of the sites that were formerly vegetated with this species but that currently remain unvegetated. Therefore, the current distribution of Z. marina likely represents the extent of suitable environmental conditions in the region, and the lack of recovery into historically vegetated sites is not solely due ...


Effects Of The June 1995 Freshet On The Main Virginia Tributaries To The Chesapeake Bay, Herbert M. Austin, Christopher F. Bonzek Jan 1996

Effects Of The June 1995 Freshet On The Main Virginia Tributaries To The Chesapeake Bay, Herbert M. Austin, Christopher F. Bonzek

VIMS Articles

Environmental conditions in the Virginian waters of the Chesapeake Bay area during the summerof 1995 have been characterized as a severe drought. This drought was punctuated on 27 June with a headwater (James and Rappahannock River) rain storm that produced a "freshet". Although it did not rain in the Tidewater area of Virginia, surface salinities were depressed by the run-off, and main-stem bottom ox}'gen levels dropped to z.ero in the James and Rappahannock rivers. The effects of the reduced oxygen were apparent on the James River oyster stock, particularly the reduction in spatfall, and to a lesser degree ...


Optimal Culture Conditions For The Propagation Of The Oyster Pathogen Perkinsus Marinus (Apicomplexa) In Protein Deficient Medium, Jf Lapeyre, M Faisal Jan 1996

Optimal Culture Conditions For The Propagation Of The Oyster Pathogen Perkinsus Marinus (Apicomplexa) In Protein Deficient Medium, Jf Lapeyre, M Faisal

VIMS Articles

The protozoan, Perkinsus marinus, acclimated and proliferated in the culture medium JL-ODRP-1 without bovine serum albumin. The principal culture conditions for the optimal propagation of P. marinus in this protein deficient culture medium, were determined. The greatest growth rates of the parasite occurred at 28 degrees C, 661 mOsm/kg and pH 7.5. Decreasing seeding densities from 16 x 10(5) to 1 x 10(5) also increased growth rate. After several passages in the absence of 5% CO2 tension, the growth rate of P. marinus was similar to its original value in the presence of 5% CO2 tension ...


Shell Disease In The Gold Lip Pearl Oyster, Pinctada Maxima And The Eastern Oyster, Crassostrea Virginica, Frank O. Perkins Jan 1996

Shell Disease In The Gold Lip Pearl Oyster, Pinctada Maxima And The Eastern Oyster, Crassostrea Virginica, Frank O. Perkins

VIMS Articles

A description is provided of the anomalous conchiolin deposits which are formed by Pinctada maxima and which are associated with unusual morta]jties. Comparisons are made with brown ring disease found in Ruditapes philippinarum and juvenile Crassostrea virg inica. In P. maxima, the deposits are not organized into a ring but rather a.re broad-based and result in retraction of the mantle with the deposits lying outside the edge of the mantle. Vibrio sp. have been implicated in causing the di seases of P. max ima and R. philippinarum whereas the etiological agent of the disease in C. virginica is ...


Demographic Analysis Of The Sandbar Shark, Carcharhinus Plumbeus In The Western North Atlantic, Tr Sminkey, Ja Musick Jan 1996

Demographic Analysis Of The Sandbar Shark, Carcharhinus Plumbeus In The Western North Atlantic, Tr Sminkey, Ja Musick

VIMS Articles

The sandbar shark, Carcharhinus plumbeus, is the most common large coastal shark in Virginia waters and is an important component of recreational and commercial fisheries along the east coast of the United States. Sandbar shark demographic analyses, using known and estimated life history parameters, including fishing mortality (F) at ages and levels estimated in a recent stock assessment, were used to estimate potential population growth and exploitation. Life history tables were constructed by using best estimates of natural mortality (M) of O.11 or 0.07 for maximum ages of 30 or 60 yr, respectively. Natality was fixed at 2 ...


Foreword, Frank O. Perkins Jan 1996

Foreword, Frank O. Perkins

VIMS Articles

No abstract provided.