Carotenoid Accumulation in Common and Orange-Muscle Mutant of Abalone, Haliotis gigantea, Fed with Different Macroalgae

Abstract

Aquatic animals cannot synthesize carotenoids, thus they must come from diet or from symbionts. Previous studies have found that orange-muscle abalones are rich in carotenoids, but the effects of different diets on the accumulation of carotenoids are unknown. In this study, the effects of macroalgae (Gracilaria lemaneiformis), fresh and dried kelp (Laminaria japonica) on the contents of the predominant carotenoids, including zeaxanthin, β-carotene, and fucoxanthin, between the common and orange-muscle mutant of Haliotis gigantea were compared through a one-year culture experiment. Our study confirmed that carotenoids in abalones mainly come from diets, and the carotenoid types in the muscles were similar to their diets. We also found that feeding on G.lemaneiformis played an important role in maintaining a stable carotenoid content over time, especially zeaxanthin in H.gigantea. Our data also provided that abalones had a good growth performance under the feeding conditions of G.lemaneiformis. Finally, compared with common abalones, orange-muscle abalones had a notably enhanced ability to accumulate carotenoids through their diet, especially zeaxanthin ( $P<0.01$ ). However, the growth performance of orange-muscle abalones was lower than those of common abalones fed the same diets. These results inferred that the content of carotenoid in abalone may be controlled by genetic factors, and diet had a significant influence on the accumulation of carotenoid in abalone to some extent.