Genetic parentage reconstruction as a practical tool applied to aquaculture and restoration programs for the European flat oyster, <i>Ostrea edulis</i>

Preserving and maximizing genetic diversity in conservation programs, including for restocking, are of high importance. The threatened European flat oyster ( Ostrea edulis ) is currently the subject several applied restocking but concerns have been raised over potential negative side effects these example due to our limited knowledge about natural populations releasing offspring hatchery origin. Here, we developed an effective, easily applicable highly reliable method assess parental contributions production based on analyses 17 microsatellite loci. We analysed four broodstocks their hatchery-reared spat (total n = 354) compared that wild samples adults from broodstock source Limfjorden 138). Based tank experiments with fully resolved parentage assignments, found five swarming events (larval releases) were characterized by a single maternal multiple paternal contributions, number contributing parents varied greatly both among individual tanks, between within tank. On average, effective breeders was only one third actual size. Although exhibited variation, reproductive skew resulted produced representing relatively small subset this variation. work demonstrates impact reared decreasing populations, also monitoring can be integrated programs minimize restoration supplementary utilize spats support populations.