Towards Fish Lipid Nutrigenomics: Current State and Prospects for Fin-Fish Aquaculture

TLDR

Lipids are the main energy source for fish, and their allocation to metabolism, growth, and reproduction is key to life‑history strategies; however, aquaculture relies heavily on fish oil, whose supply is at its maximum sustainable limit and is projected to fall short of demand, threatening the sector’s viability. The study aims to reduce fish‑oil usage in aquaculture by deepening knowledge of lipid storage, muscle growth, and by identifying alternative feed ingredients. The review surveys recent molecular and genomic research on fin‑fish lipid metabolism, focusing on fatty‑acid and HUFA biosynthesis pathways and their transcriptional and endocrine regulation. Comparative genomics reveals gene functions and distributions that illuminate lipid homeostasis and predict the effects of replacing fish oil in diets.

Abstract

Lipids are the predominant source of energy for fish. The mechanisms by which fish allocate energy from lipids for metabolism, development, growth, and reproduction are critical for understanding key life-history strategies and transitions. Currently, the major lipid component in aquaculture diets is fish oil (FO), derived from wild capture fisheries that are exploited at their maximum sustainable limit. The increasing demand from aquaculture for FO will soon exceed supply and threaten the viability of aquaculture. Thus, it is essential to minimize FO use in aquaculture diets. This might be achieved by a greater understanding of lipid storage and muscle growth, or the identification of alternatives to FO in feeds. This review focuses on recent research applying molecular and genomic techniques to the study of fin-fish lipid metabolism from an aquaculture perspective. Accordingly, particular emphasis will be given to fatty acid metabolism and to highly unsaturated fatty acid (HUFA) biosynthesis and to the transcriptional mechanisms and endocrine factors that regulate these processes in fish. Comparative studies of gene function and distribution are described, which, when integrated with recent fish genome sequence information, provide insights into lipid homeostasis and the outcomes associated with the replacement of FO in fish diets.