The Effects of Seaweed Diets on the Lipid and Fatty Acids of the Japanese Disc Abalone Haliotis discus hannai

Abstract

The effects of seaweed diets on the lipid and fatty acid (FA) composition of juvenile abalone Haliotis discus hannai were investigated by feeding seaweeds with different FA profiles: green (Ulva pertusa, rich in 16:4n-3, 18:3n-3, and 18:4n-3 polyunsaturated fatty acids or PUFAs), red (Grateloupia sparsa, high in 20:4n-6 and 20:5n-3 PUFAs), and brown (Undaria pinnatifida, rich in 18:3n-3, 18:4n-3, 20:4n-6, and 20:5n-3 PUFAs), in a 66-day feeding trial. The best growth was observed in juveniles fed U. pinnatifida. None of the seaweed diets affected the major lipid classes of abalone tissues. The PUFAs, 16:4n-3, 20:5n-3, and 22:5n-3 were major FAs of abalone tissues even if these were undetected or found only in very small amounts in the seaweed diet, suggesting their synthesis from dietary n-3 series of lower fatty acids. The poor growth rates were associated with seaweed diets deficient in 18:2n-6, 18:3n-3, 18:4n-3, or 20:4n-6.