Growth and biochemical profile of juvenile mussels (mytilus galloprovincialis Lmk) fed on different algal diets

Abstract

The food value of different microalgal diets to juvenile Mytilus galloprovincialis Lmk was assessed. Three different marine microalgae species (Tetraselmis suecica, Dunaliella tertiolecta and Phaeodactylum tricornutum) were fed singly and in various mixtures. Composition of the mixtures was based on the dry weight of(n~cells. Significantly higher growth rates in length and volume were obtained with diets containing T. suecica. Differences in food value between diets containing T. suecica and the remainder also were observed in terms of growth in dry and organic weights, gross growth efficiencies and condition indexes. All these parameters were correlated significantly with each other. The biochemical profile of the mussels also was modified by the diet. Mussels fed on diets containing D. tertiolecta showed increased levels of carbohydrales. Growth rates, gross growth efficiencies and condition indexes were correlated significantly with the protein and lipid deposited as body constituents, and lipid content (%DW) of the mussels. In the diets of higher growth, 44-47% of algal protein supplied was deposited as body protein, against 4.2-4.5% of Jipids and 33-64% of carbohydrates.