For a sustainable aquaculture industry, current levels of fish meals/oils in aquafeeds
need to be drastically reduced and mostly replaced by alternate counterparts. In this contest, the use
of marine microalgae in aquafeeds has recently attracted much scientific attention due to their high
protein content and lipid levels, including ω-3 long-chain PUFAs. In the present study, we investigated
the growth performance and body composition of sea bass (Dicentrarchus labrax, L., 1758) in response
to diets where graded levels of a blend of two marine microalgae (Isochrysis aff. galbana (T-ISO) and
Tetraselmis suecica) were included in low fish meal/oil diets. The microalgae-containing aquafeeds were
also compared to a diet (negative control) with a 30:70 fish to vegetable protein-lipid ratios. Fish given
the positive control feed and those fed diets including graded levels of microalgae showed similar growth
performance and feed conversion ratios which were significantly better than those attained by fish fed
the negative control diet (B.W. 420 vs 388 g, SGR 0.69 vs 0.61, FCR, 1.7 vs 1.9, p<0.05). The effects
of the dietary microalgae inclusion on fillet fatty acid composition and intestinal brush border enzyme
activity were also considered.
