scholarly journals Genetic Variation in the Timing of Gonadal Maturation and Spawning of the Eastern Oyster, Crassostrea virginica (Gmelin)

1991 ◽  
Vol 181 (2) ◽  
pp. 216-221 ◽  
Author(s):  
B. J. Barber ◽  
S. E. Ford ◽  
R. N. Wargo
Keyword(s):  
Genetic Variation ◽  
Crassostrea Virginica ◽  
Eastern Oyster ◽  
Gonadal Maturation

Evolutionary Change in the Eastern Oyster, Crassostrea Virginica, Following Low Salinity Exposure

2021 ◽  
Author(s):  
Joanna S Griffiths ◽  
Kevin M Johnson ◽  
Morgan W Kelly
Keyword(s):  
Genetic Variation ◽  
Crassostrea Virginica ◽  
Larval Stage ◽  
Genetic Load ◽  
Early Life History ◽  
Eastern Oyster ◽  
Evolutionary Change ◽  
Low Salinity ◽  
Multiple Loci ◽  
Breeding Grounds

Synopsis The presence of standing genetic variation will play a role in determining a population's capacity to adapt to environmentally relevant stressors. In the Gulf of Mexico, extreme climatic events and anthropogenic changes to local hydrology will expose productive oyster breeding grounds to stressful low salinity conditions. We identified genetic variation for performance under low salinity (due to the combined effects of low salinity and genetic load) using a single-generation selection experiment on larvae from two populations of the eastern oyster, Crassostrea virginica. We used pool-sequencing to test for allele frequency differences at 152 salinity-associated genes for larval families pre- and post-low salinity exposure. Our results have implications for how evolutionary change occurs during early life history stages at environmentally relevant salinities. Consistent with observations of high genetic load observed in oysters, we demonstrate evidence for purging of deleterious alleles at the larval stage in C. virginica. In addition, we observe increases in allele frequencies at multiple loci, suggesting that natural selection for low salinity performance at the larval stage can act as a filter for genotypes found in adult populations.

scholarly journals Transgenerational plasticity and the capacity to adapt to low salinity in the eastern oyster, Crassostrea virginica

2021 ◽  
Vol 288 (1951) ◽  
pp. 20203118
Author(s):  
Joanna S. Griffiths ◽  
Kevin M. Johnson ◽  
Kyle A. Sirovy ◽  
Mark S. Yeats ◽  
Francis T. C. Pan ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Crassostrea Virginica ◽  
Salinity Tolerance ◽  
Eastern Oyster ◽  
Important Species ◽  
Transgenerational Plasticity ◽  
Low Salinity ◽  
Breeding Grounds ◽  
Commercially Important ◽  
Local Hydrology

Salinity conditions in oyster breeding grounds in the Gulf of Mexico are expected to drastically change due to increased precipitation from climate change and anthropogenic changes to local hydrology. We determined the capacity of the eastern oyster, Crassostrea virginica , to adapt via standing genetic variation or acclimate through transgenerational plasticity (TGP). We outplanted oysters to either a low- or medium-salinity site in Louisiana for 2 years. We then crossed adult parents using a North Carolina II breeding design, and measured body size and survival of larvae 5 dpf raised under low or ambient salinity. We found that TGP is unlikely to significantly contribute to low-salinity tolerance since we did not observe increased growth or survival in offspring reared in low salinity when their parents were also acclimated at a low-salinity site. However, we detected genetic variation for body size, with an estimated heritability of 0.68 ± 0.25 (95% CI). This suggests there is ample genetic variation for this trait to evolve, and that evolutionary adaptation is a possible mechanism through which oysters will persist with future declines in salinity. The results of this experiment provide valuable insights into successfully breeding low-salinity tolerance in this commercially important species.

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.

Transcriptomic signatures of temperature adaptation in the eastern oyster Crassostrea virginica

2021 ◽  
Author(s):  
Kevin M. Johnson ◽  
Hollis R. Jones ◽  
Sandra M. Casas ◽  
Jerome F. La Peyre ◽  
Morgan W. Kelly
Keyword(s):  
Crassostrea Virginica ◽  
Eastern Oyster ◽  
Temperature Adaptation

scholarly journals Heritability of acute low salinity survival in the Eastern oyster (Crassostrea virginica)

Aquaculture ◽  
2020 ◽  
Vol 529 ◽  
pp. 735649
Author(s):  
Alexandra J. McCarty ◽  
K. McFarland ◽  
J. Small ◽  
S.K. Allen ◽  
L.V. Plough
Keyword(s):  
Crassostrea Virginica ◽  
Eastern Oyster ◽  
Low Salinity
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