Crossbreeding Pacific oysters for high yield through on-farm evaluation

SUMMARY: Improving broodstock for hatcheries is an urgent research focus for the molluscan shellfish aquaculture industry. Shellfish growers on the U.S. West Coast depend largely on hatchery-produced seed and are poised to take advantage of genetic improvement of farmed stocks. There is growing evidence that crossbreeding a within-species breeding innovation contributing to the massive improvement for major land crops can substantially improve yields for marine bivalves including the Pacific oyster (Crassostrea gigas). In the SBIR Phase I project we produced a cohort of multi-generation pair-mated families that expanded our broodstock repository to more than 100 distinct families including new hybrid lines. Field research at five farm sites revealed large variation in first-summer yield for seed between different families. Crossbreeding of top-performing lines to provide improved stocks for specific farm conditions will be evaluated through rigorous on-farm trials in this proposed Phase II efforts. Specifically we propose to (1) evaluate families during the second field season for yield gonadal development shell morphometrics and growth uniformity; (2) produce elite hybrid lines based on two years of field studies using inbred lines maintained in the broodstock repository; (3) produce commercial quantities of double hybrids for further on-farm evaluation at participating shellfish farms across the West Coast. This proposal builds on proven cases of hybrid vigor in marine bivalves and established facilities and resources of Pacific Hybreed. Outcomes of this research will provide the shellfish aquaculture industry hybrid lines to capitalize on benefits of hybrid vigor and establish important biological resources for the research community. SBIR TOPIC AREA 8.7: Aquaculture