Choosing     BroodstocksÂ
Mass Selected vs. Family Selected Lines
Disease resistant and triploid stocks are produced under license with the the College of William and Mary. Breeding work by the Aquaculture Genetics, and Breeding Technology Center (ABC) at Virginia Institute of Marine Science (VIMS).
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Advancements in oyster breeding technology by VIMS-ABC is largely credited for the existence and widespread success of Virginia’s oyster aquaculture industry. The process of selective breeding has enabled ABC to create distinct lines of genetically superior, disease resistant brood stock made available for hatcheries to propagate and sell as seed. OSH offers 4 different product lines from ABC for our farmers to choose from to best suit their growing location: DEBY, LOLA, HNRY and LILY.
So, which one should you choose and what’s the difference? The two main differentiators when it comes to these line options are 1.) the mode of selection (mass selected vs. family breeding), and 2) the salinity in which they have been selected.​
MASS-SELECTED LINES
DEBY and LOLA
Mass selection was used as the principle means to attain disease resistance, by breeding survivors. Later, larger oysters were also selected. The resulting two lines (DEBY, LOLA) were the foundation of early releases of brood stock by ABC. Now, little selective pressure is applied to DEBY and LOLA and the focus is maintenance of genetic health of the lines.
FAMILY-SELECTED LINES
HNRY and LILY
The family selected lines are undergoing intense, directed selection by ABC, with continual improvements each generation. These newest improvements are provided to OSH each year. Family breeding provides a means of adding multiple traits, such as meat yield and cup shape to the principle ones of disease resistance and fast growth. HNRY (high salinity) and LILY (low salinity) are tested in separate environments to provide a full range of performance across mid-Atlantic conditions.
Virginia Stocks
1
MASS-SELECTED LINE
DEBY
A medium to high salinity stock. MSX resistant and Dermo tolerant. The ancestors of this stock are from Delaware Bay MSX resistant lines, but have been selected for disease resistance in York River for over 20 years. This stock is a good all around performer with a proven track record.
2
MASS-SELECTED LINE
LOLA
A low to medium salinity stock with moderate resistance auto MSX and high tolerance to Dermo. Notable for good growth performance at low salinities. The ancestors of this stock come from Louisiana and have been hybridized to mid-Atlantic lines. This stock exhibits fast growth, but less MSX resistance than others.
3
FAMILY-SELECTED LINE
HNRY
A medium to high salinity stock. MSX resistant and Dermo tolerant. The ancestors of this stock are a composite of early mass-selected high salinity lines that are now bred using family breeding techniques. Selection traits include: fast growth, high survival, shell shape, and high meat-shell ratio.
4
FAMILY-SELECTED LINE
LILY
A low salinity stock with less disease tolerance, but good growth performance at low salinity. The ancestors of this stock are a composite of early mass-selected lines with established disease tolerance that are now bred using family breeding techniques. Selection traits include: fast growth, high survival, shell shape, and high meat-shell ratio.
Triploids
Explained
To make the triploid, OSH uses tetraploid lines, also created and improved at ABC, to cross with the diploid line, which yields triploids.
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DIPLOID FEMALE x TETRAPLOID MALE = TRIPLOID SEED
HATCHERY TO FARM
The Special Case for
Making Triploids
As described above, growers have the ability to select from a number of lines that have shown their utility for various growing conditions in the mid-Atlantic. Finding the right one for you is ultimately a function of your specific farm conditions and grow out techniques and therefore a matter of trial and error. If you are currently using a particular line, and want to try another, try a small quantity of the new line before jumping ship. Whichever line you settle on, most people use the triploid version of it.
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There are several tetraploid lines available to OSH from ABC. OSH chooses what tetraploid line to use based on the latest information from ABC. We currently do not offer growers the opportunity to select which tetraploids are used in the cross as tetraploids have been specifically bred to be generalists across farm locations and tests by ABC have shown that triploids produced from any of the tetraploid lines perform equally.
