but the yield from RAS in the second experiment was only half of the FTS yield. Our results with mean survival in FTS of 47.4% and yield of 40.2% of D3 compares well with the first results from a large volume (4700 L) flow-through culture on yield of pediveligers of 50% obtained by Andersen et al. (2000).The results were higher than the first results obtained in our system by Magnesen et al. (2006), who found that mean survival was 20% (range 0–70%) and yield 7% (range 0–20%). The results compares well with results from later studies in the same system, when Magnesen and Christophersen (2008) found 30–64% survival and 18.5–58.7% yield in the 3500 L system