The Use of Reproductive Technology to Improve Flounder Growth

Summer flounder (Paralichthys dentatus) are a valuable commercial and recreational species with a natural range from the southern Gulf of Maine to South Carolina. Landings of Atlantic flounders decreased from 90,000 mt in 1984 to 25,000 mt in 1994. Total annual landings of summer flounder peaked at 39.9 million pounds in 1979, but recently from 1990-2003 landings have been much lower, fluctuating from 9 million pounds to 14 million pounds, well off historic demand. This decline is primarily due to overfishing, as the stock is dominated by immature fish aged two years or younger. Significant increases in production from wild stocks are unlikely, since they are now being harvested beyond their maximum sustainable yield. The increasing demand for these seafood products can only be satisfied through aquaculture and stock enhancement programs. Growth rate remains the dominant factor controlling profitability of land-based culture of this species. If a breeding program could improve growth rate two-fold over a period of years, the cost of production would drop from $2.80 to only $2.00/lb. The purpose of this project is to develop the techniques to produce broodstock summer flounder that when spawned will produce only genetic females. Females of this flounder species grow faster than males and would be more economical to produce than males