The use of preserved copepods in seabream aquaculture: biometric, biochemical and molecular implications.

The aim of the present study was to test the efficiency of a new technology able to produce preserved copepods to be used as a possible alternative to live preys (rotifers, Artemia nauplii and live copepods). Different feeding combinations and different preserved copepod sizes have been tested in order to verify the efficiency of this innovative larval food on a very common cultured species in the Mediterranean area: Sparus aurata. In this study, we demonstrated that during the early larval periods, a crucial role is played by prey motion and their biochemical characteristics. In fact, static live preys represent a limiting factor in larval rearing that in turn negatively affects growth and survival A 100% preserved copepod diet was not able to promote larval survival, however, a mixed diet based on live and preserved preys may be a good choice to enhance larval survival and growth in fish larvae. The technology herein developed underlines that preserved copepods can maintain their fatty acid composition and thus can be considered as a valid source of highly unsaturated fatty acids (HUFAs) in aquaculture. In fact, as already demonstrated in previous studies, HUFAs are able to positively modulate the expression of important genes involved in larval growth, lipid metabolism, food intake and stress tolerance.