A two and a half year study was conducted to compare the performance of sibling diploid and triploid Sydney rock oysters Saccostrea commercialis (Iredale and Roughley) at three intertidal and one subtidal site in Port Stephens, New South Wales (NSW).

The findings of this study have major implications for the NSW oyster industry as triploid Sydney rock oysters have good consumer acceptability, reach market size 6-18 months faster and maintain better meat condition than diploid oysters without an increased risk of winter mortality.

This project has been very successful and has generated considerable demand for triploid oysters from Tasmanian oyster farmers. From the batch of triploids, described above and produced by the FROG research team and Shellfish Culture Pty Ltd, 800 000 triploid spat were made available to Tasmanian and South Australian farmers. Feedback was generally favourable. A new research grant application (Commercialisation of triploid Sydney rock and Pacific oysters) was made to FROG to help overcome problems in hatcheries which previously had been unsuccessful with meeting this demand.

Keywords: farming, triploid, oysters, growth, disease