Using nutrigenomics to evaluate microdiet performance in pike silverside larvae

This work aimed to evaluate the nutrigenomic effect of feeding pike silverside larvae with rotifer versus a formulated microdiet. Survival of larvae was evaluated across the experiment, while growth performance and transcriptional expression profiles in both dietary treatments were compared at the end. Larvae fed with rotifers achieved higher growth and survival, and in accordance, relevant genes associated with growth and development were overexpressed. Moreover, genes associated with digestive enzymes were overexpressed in larvae fed with rotifers, suggesting this to be an average expression profile that may give insight into the digestive status/capacity of pike silverside larvae. On the contrary, the overexpression of genes related to stress, genome instability and epigenetic marks could explain the low larval performance observed in the microdiet fed larvae. These findings point out the relevance of a nutrigenomic approach as an important tool to assess artificial diet performance in fish and the necessity to re‐evaluate formulation, type and proportion of the ingredients in the microdiet which may reflect similar expression profiles found in the rotifer group and provide adequate growth in early larval stages of pike silverside. This information contributes to the knowledge of the limitations of microdiets in pike silverside and other fish larvae.