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Full-Text Articles in Life Sciences

Multiple Drivers Of Interannual Oyster Settlement And Recruitment In The Lower Chesapeake Bay, Brendan Turley, Kimberly S. Reece, Jian Shen, Jeong-Ho Lee, Ximing Guo, Jan Mcdowell May 2019

Multiple Drivers Of Interannual Oyster Settlement And Recruitment In The Lower Chesapeake Bay, Brendan Turley, Kimberly S. Reece, Jian Shen, Jeong-Ho Lee, Ximing Guo, Jan Mcdowell

VIMS Articles

Despite global investment in shellfish restoration activities, relatively little attention has been given to predicting optimal restoration sites and testing these expectations. We used a coupled biological-physical connectivity model as a guide to plant two distinct hatchery-spawned strains of the eastern oyster, Crassostrea virginica, in the Lafayette River, Virginia during the summer of 2013 at two locations corresponding to virtual spawning locations within the connectivity model. We utilized single nucleotide polymorphism markers to test the model predictions by genotyping oysters recruited after planting two hatchery-spawned strains and examining interannual recruitment variability for two successive years. Two spat were identified as ...


Tracking Triploid Mortalities Of Eastern Oysters Crassostrea Virginica In The Virginia Portion Of The Chesapeake Bay, Eric Guevelou, Ryan Carnegie, Ja Moss, Karen Hudson, Kimberly S. Reece, Molly M. Rybovich, Standish K. Allen Jr. Jan 2019

Tracking Triploid Mortalities Of Eastern Oysters Crassostrea Virginica In The Virginia Portion Of The Chesapeake Bay, Eric Guevelou, Ryan Carnegie, Ja Moss, Karen Hudson, Kimberly S. Reece, Molly M. Rybovich, Standish K. Allen Jr.

VIMS Articles

Since 2012, aquacultured eastern oysters Crassostrea virginica have been reported by oyster farmers to display mortality approaching 30%, and in some cases 85%, in areas of the lower Chesapeake Bay, VA. Based on accounts from industry, this mortality has typically affected 1-y-old oysters between May and early July, and has tended to occur in triploid oysters, which represent the vast bulk of production in the area. During this period, samples submitted for pathology have not revealed the presence of major pathogens as a cause. In 2015, to gain deeper insight into this mortality and determine whether specific sites, ploidy condition ...


Differential Effects Of Bivalves On Sediment Nitrogen Cycling In A Shallow Coastal Bay, Ashley Smyth, Anna E. Murphy, Iris C. Anderson, Bk Song Jan 2017

Differential Effects Of Bivalves On Sediment Nitrogen Cycling In A Shallow Coastal Bay, Ashley Smyth, Anna E. Murphy, Iris C. Anderson, Bk Song

VIMS Articles

In coastal ecosystems, suspension-feeding bivalves can remove nitrogen though uptake and assimilation or enhanced denitrification. Bivalves may also retain nitrogen through increased mineralization and dissimilatory nitrate reduction to ammonium (DNRA). This study investigated the effects of oyster reefs and clam aquaculture on denitrification, DNRA, and nutrient fluxes (NOx, NH4 6 +, O2). Core incubations were conducted seasonally on sediments adjacent to restored oyster reefs (Crassostrea virginica), clam aquaculture beds (Mercenaria mercenaria) which contained live clams, and bare sediments from Smith Island Bay, Virginia, USA. Denitrification was significantly higher at oyster reef sediments and clam aquaculture site than bare sediment in the ...


Observations Of Distribution, Size, And Sex Ratio Of Mature Blue Crabs, Callinectes Sapidus, From A Chesapeake Bay Tributary In Relation To Oyster Habitat And Environmental Factors, Jm Harding, R Mann Jan 2010

Observations Of Distribution, Size, And Sex Ratio Of Mature Blue Crabs, Callinectes Sapidus, From A Chesapeake Bay Tributary In Relation To Oyster Habitat And Environmental Factors, Jm Harding, R Mann

VIMS Articles

Blue crabs Callinectes sapidus (Rathbun, 1896) > 100 mm carapace width were sampled from a constructed oyster reef (1996 and 1997), a sand bar (1997) and a natural oyster bar (1997) in the Piankatank River, Chesapeake Bay, USA to describe habitat use, sex ratios, and demographics across a gradient of habitat types. Patterns of blue crab catch-per-unit-effort (CPUE), and demographics were similar on the oyster reef in 1996 and 1997. Average annual CPUE on the reef was 6-8 crabs pot(-1) with maximum CPUE of 15 crabs pot(-1). Daylength and water temperature significantly affected reef CPUE with more crabs observed ...


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 ...


Effect Of Neutral Red Stain On Settlement Ability Of Oyster Pediveligers, Crassostrea Virginica, Patrick Baker Jan 1991

Effect Of Neutral Red Stain On Settlement Ability Of Oyster Pediveligers, Crassostrea Virginica, Patrick Baker

VIMS Articles

The effect of neutral red stain on the settlement of oyster Crassostrea virginica (Gmelin) pediveligers was examined. Larvae were offered two types of substrate: oyster shell and acetate sheets. Settlement was measured as the proportion of pediveligers settled after 24 hours and analyzed with two-factor ANOV A. Staining did not significantly affect settlement, although settlement onto acetate was much lower than onto oyster shell.


Effect Of Decreasing Oxygen Tension Of Swimming Rate Of Crassostrea Virginica (Gmelin, 1791) Larvae, Roger L. Mann, Julia S. Rainer Jan 1990

Effect Of Decreasing Oxygen Tension Of Swimming Rate Of Crassostrea Virginica (Gmelin, 1791) Larvae, Roger L. Mann, Julia S. Rainer

VIMS Articles

Four sizes of Crassostrea virginica Gmelin larvae (mean lengths 76.8, 118.1, 139.7 and 290.2 [Lm) were exposed to ·stepwise decreases in oxygen concentration from I 00% saturation (5 .38 mill at 22°C and 22 ppt salinity) to as low as 10% saturation and their swimming rates (net vertical movement per unit time) were recorded at each oxygen concentration. No cessation of swimming was observed and in only two conditions, that of 76.8 [Lm larvae at 10% saturation and 290.2 j.Lm larvae at 21% saturation, was swimming rate significantly lower than that of ...


Recruitment And Growth Of Oysters On Shell Planted At Four Monthly Intervals In The Lower Potomac River, Maryland, Reinaldo Morales-Alamo, Roger L. Mann Jan 1990

Recruitment And Growth Of Oysters On Shell Planted At Four Monthly Intervals In The Lower Potomac River, Maryland, Reinaldo Morales-Alamo, Roger L. Mann

VIMS Articles

Oyster shells were planted on four successive months (May to August 1986) in contiguous plots at Jones Shore Bar in the Potomac River, Maryland, to study the effect of differences in time of cultch planting on settlement and survival of oyster spat. The plots were usually sampled at two-week intervals from time of planting through November, 1986, and once in June, 1987. A massive concentration of the tunicate Molgula manhattensis covered the bottom in all plots within four to six or eight weeks following shell planting. A commercially acceptable number of spat per shell, between 1.8 and 2.2 ...


Settlement Patterns Of Crassostrea Virginica (Gmelin, 1791) Larvae In Relation To Tidal Zonation, G. Curtis Roegner, Roger L. Mann Jan 1990

Settlement Patterns Of Crassostrea Virginica (Gmelin, 1791) Larvae In Relation To Tidal Zonation, G. Curtis Roegner, Roger L. Mann

VIMS Articles

Experiments were conducted to determine the settlement distribution of the oyster Crassostrea virginica (Gmelin) in relation to tidal zonation in an area where adult populations are largely confined to the intertidal zone. Hatchery-reared pediveliger larvae were interned in PVC tubes positioned at known tidal heights. The influence of non-tidal factors was limited: mesh covering the ends of the tubes prevented loss of larvae to dispersal or predation, the settling substrate was not colonized by competitors, and the effects of light and horizontal currents were minimized. Settlement was found to occur throughout the intertidal zone but predominated at the bottom of ...


Anatomical Features In Histological Sections Of Crassostrea Virginica (Gmelin, 1791) As An Aid In Management Of Gonad Area For Reproductive Assessment, Reinaldo Morales-Alamo, Roger L. Mann Jan 1989

Anatomical Features In Histological Sections Of Crassostrea Virginica (Gmelin, 1791) As An Aid In Management Of Gonad Area For Reproductive Assessment, Reinaldo Morales-Alamo, Roger L. Mann

VIMS Articles

The relationship between gonad area in transverse histological sections of the American oyster Crassostrea virginica (Gmelin 1790) and body location from which the section was cut was studied in specimens collected from four stations in the James River, Virginia in 1984 and 1986. Gonad area, expressed as percentage of total body area, increases in an antero-posterior direction; this requires use of sections from the same body location in comparisons between oysters. Approximate body locations, identified according to the anatomy and arrangement of the internal organs in the sections, were grouped into five types with similar gonad area percentages. One of ...


Predation On Single Spat Oysters Crassostrea Virginica (Gmelin) By Blue Crabs Callinectes Sapidus Rathbun And Mud Crabs Panopeus Herbstii Milne-Edwards, Robert Bisker, Michael Castagna Jan 1987

Predation On Single Spat Oysters Crassostrea Virginica (Gmelin) By Blue Crabs Callinectes Sapidus Rathbun And Mud Crabs Panopeus Herbstii Milne-Edwards, Robert Bisker, Michael Castagna

VIMS Articles

Single spat oysters Crassostrea virginica of four size classes (3.4-24.6 mm mean shell heights [SH]) were offered to six size classes of blue crabs Ca/linectes sapidus (9.3-85.5 mm mean carapace width [CW]) and five size classes of mud crabs Panopeus herbstii (7.1-34.4 mm mean CW) for 48 hr. Predation rate, recorded as the number of dead oyster spat/crab/day, was directly proportional to crab size and inversely proportional to oyster size. Mud crabs of 34.4 mm CW and blue crabs of 85 .5 mm CW had predation rates of 22.5 ...