Nutritional programming in fishes: insights from mammalian studies

Epidemiological evidence and subsequent studies using mammalian models have established a strong correlation between suboptimal nutritional status during early life and predisposition to metabolic diseases later, such as permanent growth retardation and impairment of neural development and key metabolic pathways. This phenomenon, termed nutritional programming or metabolic programming, is beginning to be studied in fishes. Despite important differences in maternal nutrient delivery and developmental processes between mammals and fishes, early nutrition of fishes from both endogenous (maternally derived) and exogenous (larval feeding) sources, could induce similar programming effects on development and metabolism. Documented programming effects in fishes include: growth, survival, brain development, and nutrient metabolism. These programming effects could be mediated through altered metabolic pathways and/or epigenetic regulation of gene expression during a critical window when organisms exhibit high plasticity in development. As a result, nutritional programming could be employed as a strategy in aquaculture to promote sustainable feeding strategies. In addition, this critical window overlaps with high mortality during the early life stages. This means programming effects could potentially translate into measurable consequences for the dynamics of wild populations. Given the wide variety of metabolic consequences of programming and the diversity of fishes, many important questions remain unanswered. This report summarizes research from mammalian and fish models and identifies knowledge gaps and priority areas for research into nutritional programming in fishes.