GROWTH AND BIOCHEMICAL PROFILE OF JUVENILE MUSSELS (MYTILUS-GALLOPROVINCIALIS LMK) FED ON DIFFERENT ALGAL DIETS

The food value of different microalgal diets to juvenile Mytilus gallo provincialis Lmk was assessed. Three different marine microalgae speci es (Tetraselmis suecica, Dunaliella tertiolecta and Phaeodactylum tric ornutum) were fed singly and in various mixtures. Composition of the m ixtures was based on the dry weight of the cells. Significantly higher growth rates in length and volume were obtained with diets containing T. suecica. Differences in food value between diets containing T. sue cica and the remainder also were observed in terms of growth in dry an d organic weights, gross growth efficiencies and condition indexes. Al l these parameters were correlated significantly with each other. The biochemical profile of the mussels also was modified by the diet. Muss els fed on diets containing D. tertiolecta showed increased levels of carbohydrates. Growth rates, gross growth efficiencies and condition i ndexes were correlated significantly with the protein and lipid deposi ted as body constituents, and lipid content (%DW) of the mussels. In t he diets of higher growth, 44-47% of algal protein supplied was deposi ted as body protein, against 4.2-4.5% of lipids and 33-64% of carbohyd rates.