Evaluation of the Microalgal Substitute M-1 as a Diet for Juvenile Sydney Rock Oyster, Saccostrea glomerata (Gould 1850)

To investigate ways to reduce Sydney rock oyster, Saccostrea glomerata (Gould 1850) hatchery operational costs, an artificial diet “M-1” was tested for use with S. glomerata spat. The “M-1” diet was either fed as a sole food source or combined with fresh algae, Chaetoceros muelleri, at various concentrations ranging from 10% M-1 to 90% M-1 in 10% increments. Spat were fed each of the diets for 10 days and their growth and survival were compared with spat fed the current commercial hatchery diet of 50% C. muelleri, 25%, Tahitian Isochrysis aff. galbana and 25% Pavlova lutheri. A diet of solely M-1 produced comparatively poor growth, while diets containing between 30-80% M-1 produced growth comparable to that of the current commercial hatchery diet. The greatest growth rate recorded in this trial was produced by a diet of 50% M-1 and 50% C. muelleri. Although this diet does not overcome the need for live algal cultures, it significantly reduces the cost and complexity of the diet in comparison to that currently used for commercial S. glomerata production.