Lipid metabolism in fish and shellfish

Lipid metabolism encompasses many important and often complicated biochemical reactions, mostly involved in pathways for the synthesis of structural and functional lipids to meet the requirements of organ development and growth, and for the breakdown of storage lipids to provide energy to support all physiological processes. In aquaculture, dysfunctions of lipid metabolism are common and observed in a number of phenotypes, such as, for example, excessive lipid deposition in liver and/or mesenteric tissue. In addition, different dietary lipid sources can differentially impact growth performance and health status. Therefore a thorough understanding of the key processes and regulatory mechanisms of lipid metabolism is, not only helpful to explain why and how lipid metabolism-related diseases happen, but also useful to inform precise aquafeed formulation and develop new feeds and additives. This chapter covers the key enzymes, cellular processes, and major regulatory pathways of anabolism (biosynthesis) and catabolism (utilization) of lipids in aquatic animals.