Facing the finite size of fisheries resources, the important increase of aquaculture production during the last decades has led to the evolution of feed composition with an increasing substitution of fish meal and fish oil with terrestrial plant products. During the same period, selective breeding has been developed in fish and major improvements were achieved on growth, resulting in 4 to 20 % gain per fish generation (Olesen, Gjedrem, Bentsen et al. (2003); Chevassus, Quillet, Krieg et al. (2004)), and also on health and flesh quality traits.