Analysis of tributyltin in estuarine sediments and oyster tissue,Crassostrea virginica

1987 ◽  
Vol 1 (6) ◽  
pp. 541-544 ◽  
Author(s):  
C D Rice ◽  
F A Espourteille ◽  
R J Huggett
Keyword(s):  
Crassostrea Virginica ◽  
Estuarine Sediments ◽  
Oyster Tissue

Phages Infecting Vibrio vulnificus Are Abundant and Diverse in Oysters (Crassostrea virginica) Collected from the Gulf of Mexico

1998 ◽  
Vol 64 (1) ◽  
pp. 346-351 ◽  
Author(s):  
Angelo DePaola ◽  
Miles L. Motes ◽  
Amy M. Chan ◽  
Curtis A. Suttle
Keyword(s):  
Gulf Of Mexico ◽  
Crassostrea Virginica ◽  
Vibrio Vulnificus ◽  
Gulf Coast ◽  
Morphological Evidence ◽  
Broad Host Range ◽  
Oyster Tissue ◽  
Mobile Bay ◽  
Apalachicola Bay ◽  
Transmission Electron

ABSTRACT Phages infecting Vibrio vulnificus were abundant (>104 phages g of oyster tissue−1) throughout the year in oysters (Crassostrea virginica) collected from estuaries adjacent to the Gulf of Mexico (Apalachicola Bay, Fla.; Mobile Bay, Ala.; and Black Bay, La.). Estimates of abundance ranged from 101 to 105 phages g of oyster tissue−1 and were dependent on the bacterial strain used to assay the sample. V. vulnificus was near or below detection limits (<0.3 cell g−1) from January through March and was most abundant (103 to 104 cells g−1) during the summer and fall, when phage abundances also tended to be greatest. The phages isolated were specific to strains of V. vulnificus, except for one isolate that caused lysis in a few strains of V. parahaemolyticus. Based on morphological evidence obtained by transmission electron microscopy, the isolates belonged to the Podoviridae,Styloviridae, and Myoviridae, three families of double-stranded DNA phages. One newly described morphotype belonging to the Podoviridae appears to be ubiquitous in Gulf Coast oysters. Isolates of this morphotype have an elongated capsid (mean, 258 nm; standard deviation, 4 nm; n = 35), with some isolates having a relatively broad host range among strains of V. vulnificus. Results from this study indicate that a morphologically diverse group of phages which infect V. vulnificus is abundant and widely distributed in oysters from estuaries bordering the northeastern Gulf of Mexico.

scholarly journals Predatory blue crabs induce stronger nonconsumptive effects in eastern oystersCrassostrea virginicathan scavenging blue crabs

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3042 ◽  
Author(s):  
Avery E. Scherer ◽  
Miranda M. Garcia ◽  
Delbert L. Smee
Keyword(s):  
Habitat Selection ◽  
Food Webs ◽  
Crassostrea Virginica ◽  
Prey Availability ◽  
Oyster Tissue ◽  
Alarm Cues ◽  
Blue Crabs ◽  
Nonconsumptive Effects ◽  
Diet Cues ◽  
Reduced Risk

By influencing critical prey traits such as foraging or habitat selection, predators can affect entire ecosystems, but the nature of cues that trigger prey reactions to predators are not well understood. Predators may scavenge to supplement their energetic needs and scavenging frequency may vary among individuals within a species due to preferences and prey availability. Yet prey reactions to consumers that are primarily scavengers versus those that are active foragers have not been investigated, even though variation in prey reactions to scavengers or predators might influence cascading nonconsumptive effects in food webs. OystersCrassostrea virginicareact to crab predators by growing stronger shells. We exposed oysters to exudates from crabs fed live oysters or fed aged oyster tissue to simulate scavenging, and to controls without crab cues. Oysters grew stronger shells when exposed to either crab exudate, but their shells were significantly stronger when crabs were fed live oysters. The stronger response to predators than scavengers could be due to inherent differences in diet cues representative of reduced risk in the presence of scavengers or to degradation of conspecific alarm cues in aged treatments, which may mask risk from potential predators subsisting by scavenging.

scholarly journals Maximizing Recovery and Detection of Cryptosporidium parvum Oocysts from Spiked Eastern Oyster (Crassostrea virginica) Tissue Samples

2007 ◽  
Vol 73 (21) ◽  
pp. 6910-6915 ◽  
Author(s):  
Autumn S. Downey ◽  
Thaddeus K. Graczyk
Keyword(s):  
Crassostrea Virginica ◽  
Cryptosporidium Parvum ◽  
Environmental Protection Agency ◽  
Eastern Oyster ◽  
Tissue Homogenate ◽  
Human Consumption ◽  
Oyster Tissue ◽  
Recovery Efficiency ◽  
Tissue Samples ◽  
Contamination Levels

ABSTRACT Numerous studies have documented the presence of Cryptosporidium parvum, an anthropozoonotic enteric parasite, in molluscan shellfish harvested for commercial purposes. Getting accurate estimates of Cryptosporidium contamination levels in molluscan shellfish is difficult because recovery efficiencies are dependent on the isolation method used. Such estimates are important for determining the human health risks posed by consumption of contaminated shellfish. In the present study, oocyst recovery was compared for multiple methods used to isolate Cryptosporidium parvum oocysts from oysters (Crassostrea virginica) after exposure to contaminated water for 24 h. The immunomagnetic separation (IMS) and immunofluorescent antibody procedures from Environmental Protection Agency method 1623 were adapted for these purposes. Recovery efficiencies for the different methods were also determined using oyster tissue homogenate and hemolymph spiked with oocysts. There were significant differences in recovery efficiency among the different treatment groups (P < 0.05). We observed the highest recovery efficiency (i.e., 51%) from spiked samples when hemolymph was kept separate during the homogenization of the whole oyster meat but was then added to the pellet following diethyl ether extraction of the homogenate, prior to IMS. Using this processing method, as few as 10 oocysts could be detected in a spiked homogenate sample by nested PCR. In the absence of water quality indicators that correlate with Cryptosporidium contamination levels, assessment of shellfish safety may rely on accurate quantification of oocyst loads, necessitating the use of processing methods that maximize oocyst recovery. The results from this study have important implications for regulatory agencies charged with determining the safety of molluscan shellfish for human consumption.

Carbon Isotopes (δ13C and Δ14C) in Shell Carbonate, Conchiolin, and Soft Tissues in Eastern Oyster (Crassostrea Virginica)

Radiocarbon ◽  
2018 ◽  
Vol 60 (4) ◽  
pp. 1125-1137 ◽  
Author(s):  
Carla S Hadden ◽  
Kathy M Loftis ◽  
Alexander Cherkinsky
Keyword(s):  
Organic Matter ◽  
Carbon Isotopes ◽  
Crassostrea Virginica ◽  
Environmental Samples ◽  
Soft Tissues ◽  
Dissolved Inorganic Carbon ◽  
Eastern Oyster ◽  
Oyster Tissue ◽  
Shell Matrix ◽  
Eastern Oysters

AbstractBiogeochemical analyses of eastern oysters (Crassostrea virginica) are frequently included in environmental monitoring and paleoecological studies because their shells and soft tissues record environmental and dietary signals. Carbon isotopes in the mineral phase of the shell are derived from ambient bicarbonate and dissolved inorganic carbon (DIC), while organic carbon present in soft tissue is of dietary origin. Mineral-bound organic matter within the carbonate shell matrix (“conchiolin”) is studied less frequently. The purpose of this study was to compare carbon isotope composition (δ13C and Δ14C) of conchiolin to those of shell carbonates and soft tissues in eastern oysters and assess the extent to which conchiolin can provide insight into paleoecological records. Eleven oyster specimens were live-collected from Apalachicola Bay, USA, as well as a set of environmental samples (water, sediment, and terrestrial plants). Overall, the δ13C values in all studied oyster tissue types record environmental signals related to carbon sources, with conchiolin being enriched in 13C by an average of 2.3‰ relative to bulk soft tissues. Δ14C values in oyster shell carbonates generally reflect the marine versus riverine source of DIC, while conchiolin Δ14C values are impacted by variable relative contributions of young and old organic matter. Environmental samples indicate a significantly large difference in Δ14C among sources, from –127‰ in particulate organic matter to approximately +15‰ in DIC. Conchiolin is significantly depleted in 14C relative to other tissue types, by as much as 56.6‰, posing a major obstacle to the use of conchiolin as an alternative material for radiocarbon dating.

Spherulitic crystal growth in the prodissoconch larval of Crassostrea virginica

1983 ◽  
Vol 41 ◽  
pp. 518-519
Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee
Keyword(s):  
Crystal Structure ◽  
Crassostrea Virginica ◽  
Crystal Orientation ◽  
Developmental Changes ◽  
Gastrula Stage ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Stages Of Growth ◽  
Early Stages ◽  
Initial Deposition

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.

Tracing Estuarine Sediments by Neutron Activation

1977 ◽  
Author(s):  
Richard M. Ecker ◽  
John F. Sustar ◽  
William T. Harvey
Keyword(s):  
Neutron Activation ◽  
Estuarine Sediments

Effects of resuspension of eastern oyster Crassostrea virginica biodeposits on phytoplankton community structure

2020 ◽  
Vol 640 ◽  
pp. 79-105
Author(s):  
ET Porter ◽  
E Robins ◽  
S Davis ◽  
R Lacouture ◽  
JC Cornwell
Keyword(s):  
Water Quality ◽  
Community Structure ◽  
Crassostrea Virginica ◽  
Skeletonema Costatum ◽  
Eastern Oyster ◽  
Energy Dissipation Rate ◽  
Negative Effects ◽  
Cell Densities ◽  
Sediment Bottom ◽  
Nitrite Nitrate

Anthropogenic disturbances in the Chesapeake Bay (USA) have depleted eastern oyster Crassostrea virginica abundance and altered the estuary’s environment and water quality. Efforts to rehabilitate oyster populations are underway; however, the effect of oyster biodeposits on water quality and plankton community structure are not clear. In July 2017, we used 6 shear turbulence resuspension mesocosms (STURMs) to determine differences in plankton composition with and without the daily addition of oyster biodeposits to a muddy sediment bottom. STURM systems had a volume-weighted root mean square turbulent velocity of 1.08 cm s-1, energy dissipation rate of ~0.08 cm2 s-3, and bottom shear stress of ~0.36-0.51 Pa during mixing-on periods during 4 wk of tidal resuspension. Phytoplankton increased their chlorophyll a content in their cells in response to low light in tanks with biodeposits. The diatom Skeletonema costatum bloomed and had significantly longer chains in tanks without biodeposits. These tanks also had significantly lower concentrations of total suspended solids, zooplankton carbon, and nitrite +nitrate, and higher phytoplankton carbon concentrations. Results suggest that the absence of biodeposit resuspension initiates nitrogen uptake for diatom reproduction, increasing the cell densities of S. costatum. The low abundance of the zooplankton population in non-biodeposit tanks suggests an inability of zooplankton to graze on S. costatum and negative effects of S. costatum on zooplankton. A high abundance of the copepod Acartia tonsa in biodeposit tanks may have reduced S. costatum chain length. Oyster biodeposit addition and resuspension efficiently transferred phytoplankton carbon to zooplankton carbon, thus supporting the food web in the estuary.

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