Genetic Parameters For Crassostrea Virginica And Their Application To Family-Based Breeding In The Mid-Atlantic, Usa

A family-based breeding program was established at the Aquaculture Genetics and Breeding Technology Center (ABC) at the Virginia Institute of Marine Science beginning in 2004. Over the course of developing the program, data were acquired to determine the optimal way to structure the breeding population for the Eastern oyster, Crassostrea virginica, in the Chesapeake Bay estuary, and how best to implement our now-operational ?industrial breeding? program. Traits studied were survival, total weight, meat yield, and shell shape and decisions were based on estimates of heritability, genetic correlations, and genotype by environment interaction for these traits. Post-hoc, we examined the effect of genetic groups and genetic trends. Genetic variation was abundant and additive, with no evidence of large non-additive effects. Age: age correlations were high, allowing abbreviated field deployment to assess market qualities as early as possible. Survival at high and low salinity were poorly correlated, meaning the gene processes that control survival at each salinity zone are different, and therefore survival at high and low salinities were treated as separate traits. Total weight (indicator of growth rate) was moderately correlated between salinity zones and, while there was some commonality in genetic control across salinities (with 70% of genes in common), total weight was also treated as a separate trait at high and low salinities. Meat yield and shell shape were highly correlated among sites and can therefore be managed as a single trait across all site types. The mass selected lines from our previous work were used as a source of founders, which allowed genetic gains from those lines to be captured in the family program, thus making family-based selection a continuation of previous efforts rather than a restart. The ABC lines have found wide utility not only in the Chesapeake but also in the mid-Atlantic, defined as Rhode Island to South Carolina, USA. Familybased breeding, using the principles encapsulated in this strategy, would be appropriate as a common approach for contiguous breeding efforts for C. virginica along the east coast of the US from the Northeast to the Gulf coasts.