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ARS Home » Northeast Area » Orono, Maine » National Cold Water Marine Aquaculture Center » Research » Publications at this Location » Publication #359369

Research Project: Genetic Improvement Of Marine Fish and Shellfish

Location: National Cold Water Marine Aquaculture Center

Title: Variation in tolerance to dermo disease within an eastern oyster breeding population

item Proestou, Dina
item BEN-HORIN, TAL - University Of Rhode Island
item Markey Lundgren, Kathryn
item SULLIVAN, MARY - University Of Rhode Island
item SMALL, JESSICA - Virginia Institute Of Marine Science
item ALLEN, STANDISK - Virginia Institute Of Marine Science

Submitted to: Aquaculture America Conference
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/2018
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Resistance to Dermo is a primary target for genetic improvement in the eastern oyster; however, the trait is incompletely defined and the resistance-specific phenotypes required for precision selection are difficult to quantify. Recent disease challenge experiments indicate multiple mechanisms, including parasite avoidance and parasite elimination/inhibition, contribute to ‘resistance’. Tolerance, or the ability to sustain an intense infection without a decrease in fitness, also can affect resistance measures. Here, we present an experiment intended to characterize Dermo tolerance and how/if it varies within a breeding population. Twelve families from the Aquaculture Genetics and Breeding Technology Center’s (ABC) selective breeding program were exposed to multiple doses of the Dermo-causing parasite, Perkinsus marinus, following optimized laboratory protocols. Individual one-year old oysters from each family were injected with 106, 107, or 108 P. marinus cells per gram wet weight (N = 50 · family-1 · dose-1) and survival was monitored for eight weeks post exposure. Percent survival was calculated for each family at each dose and the relationships between survival and dose served as proxy measures for tolerance. Most families demonstrated high tolerance to P. marinus infection (80-90% survival at the highest dose), but survival fell below 65% in three families. Our preliminary analyses suggest that prior selection for field survival at sites with high parasite levels has produced Dermo-tolerant oysters, but existing variation for the trait within the breeding population can be exploited for further genetic improvement.