ABSTRACT
Current production level projections indicate that aquaculture can make a significant contribution to food security worldwide. But as with any other rapidly growing industry, it faces many challenges, among them, the use of natural resources to feed fish. Increasing aquaculture production necessarily implies more feed, increasing pressure on natural resources, marine or land based. One way to contribute toward more sustainable aquaculture growth, is to continuously improve feed conversion. To do so, improvement from both sides, the diet and its formulation as well as producing with genetically improved fish able to make more efficient use of nutrients, are absolutely necessary. A better understanding of what parameters can be used to monitor nutrient use, challenges associated with diet formulation and selecting fish, and a glimpse of the study of fish metabolism to identify pathways and markers associated with better feed conversion and nutrient retention are discussed in this chapter.
