CONTROLLED BREEDING, LARVICULTURE, AND INTENSIVE GROWOUT OF HIGH VALUE MARINE FINFISH SPECIES FOR U.S. AGRICULTURE

Southern flounder (SF, Paralichthys lethostigma) Based on research conducted in NC, culture technologies for SF are being transferred to commercial users. Solutions to the following constraints are needed to expand commercial production: Currently, we rely on wild-caught broodstock, but domesticating SF will require breeding cultured progeny for improved performance. F1 females are difficult to spawn using hormone therapies developed for wild-caught adults, and alternative hormone therapies for F1 females are needed to facilitate selective breeding programs and establish improved lines of SF. Economic analysis of a SF recirculating aquaculture system growout operation showed that fingerling costs represent 24-29% of production costs, with live rotifers representing the largest component (~15%) of fingerling production costs. Developing artifical microdiets in substitution of rotifers can significantly lower fingerling costs to farmers. The proposed research aims to enhance the development of the SF aquaculture industry in NC by solving key constraints to broodstock husbandry and to cost-effective production of fingerlings. Specific objectives are as follows: 1. Standardize hormone therapies for induced breeding of F1 females. 2. Reduce fingerling production costs by minimizing reliance on live prey through developing artificial microdiets for co-feeding and early weaning. Black Sea Bass (BSB, Centropristis striata) BSB is now in the transitional phase between research and commercial production in the eastern US. The current proposed work addresses a critical constraint to the development of a viable marine finfish culture industry in the U.S.: The use of wild-caught fish for production of fish meal as a source of protein and oil for aquaculture diets threatens wild stocks and creates economic uncertainty in aquaculture ventures. The goals of the proposed research are to promote sustainable marine finfish aquaculture by developing lower-cost feeds that rely less on dietary inclusion of fish meal. For BSB, specific objectives are as follows: 3. Evaluate substitution limits of alternative proteins (underutilized plant and animal by-products) as a fish meal replacement in diets. 4. Determine the effects of these feeds on fish biochemical composition. Red porgy We have made significant progress in understanding the spawning and larval culture requirements of RP, and post-metamorphic juveniles have been produced in our laboratory. We propose to optimize hatchery technologies and lower fingerling production costs for large-scale production of RP fingerling for pilot commercial nursery and growout projects. Specific objectives are as follows: 5. Optimize enrichment methods for live feeds. 5.1 Compare practical enrichment media, including concentrated non-viable microalgae and state-of-the-art commercial formulations. 5.2 Determine the effects of feeding cold-banked prey on larval performance. 6. Transfer technologies to the commercial end-users.