Temperature affects both larval and bacterial growth rate and hence, the success of larval culture (e.g. Douillet and Langdon, 1993; Robert and Nicholas, 2011). The higher temperature in RAS during the first experiment was, however, not unfavorable on larval yield. Merino et al. (2009) found higher growth rates and earlier settlement, but lower survival in RAS compared to a closed system when studying larval culture systems for Argopecten purpuratus. They attributed the results to reduced larval handling, more feed availability, higher temperature and more stable conditions.