Abstract: A method for rearing commercially desirable bivalve molluscs such as oysters, clams, mussels, and scallops under artificial conditions to any marketable size in substantially reduced time periods. Oyster spat (<0.5mm) produced by known means are placed in growing tanks and fed at certain regular times with certain species of algae in unusually large quantities, at unusually high algal cell concentrations, and maintained at unusually high temperatures until oysters reach the desired size. The tanks and oysters are meticulously cleansed and seawater or other source of salts and minerals is added at regular times during the rearing period.