Essential fatty acid requirements of aquatic animals with emphasis on fish larvae and fingerlings

A great deal of research has been conducted during the last 3 decades on the essential fatty acid (EFA) requirements of fish. It has been clearly demonstrated that warmwater fishes, such as carp and eels, require both n‐6 and n‐3 fatty acids, whereas cold‐water fishes, like salmonids, require only n‐3 fatty acids. Considering seawater fish as a group, we find that among the n‐3 fatty acids, the effect of linolenic acid (LNA) as an EFA is lower compared with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Larval marine fish exhibit a distinct need for DHA. The EFA requirement of other aquatic animals, such as shrimp and mollusca, also have been investigated. There exists a wide variation in the EFA requirement patterns of aquatic animals.