Organic production of herbivorous and omnivorous aquaculture
species such as tilapia and catfish appears to be relatively straight forward as organic feedstuff may largely cover their nutritional needs
and therefore readily replace conventional feedstuff (e.g., Craig and
Mclean, 2005; Li et al., 2006). Formulating organic diets for carnivorous species is a much larger challenge due to their high protein/
essential amino acid requirement and the ban against adding
synthetic amino acids in organic feed (EU, 2007). The present study