Outlines development strategies of firms which have engaged in giant clam mariculture, particularly Australian firms, with special attention being given to Reefarm Pty. Ltd., the longest surviving commercial company involved in giant clam mariculture. Considers methods which companies in this area have used for coping with business uncertainty; examines the development of Reefarm Pty. Ltd and the choice of product-mix by Reefarm. The product mix involves pearl oysters, and supply of giant clams for a variety of markets (the aquarium trade, seed sales, the restaurant trade for food and provision of tourism/educational services). The analysis indicates the importance of considering the development of firms from an evolutionary perspective.