Abstract

Juvenile abalone Haliotis tuberculata groups hatched in the lab from wild broodstock were fed with diets free of long chain polyunsaturated fatty acids (LC-PUFAs) (restriction diet) but with high amount of molecular precursors like 18:3n-3 and 18:2n-6 from linseed and corn oils compared to a control diet formulated with fish oil. Three different temperatures (12, 16 and 20 °C) were chosen to measure the effect of fatty acid accumulation or synthesis compared to the control diet. After 200 days of experimentation, abalone exhibited different growth between each temperature, whereas no differences were observed between diets. However, a higher fatty acid accumulation was observed in muscle tissue at 12 °C. The relative amount of long chain polyunsaturated fatty acids (LC-PUFAs) in themuscle tissue was similar between those individuals fed with the restriction (LC-PUFA free) and full diets. This was clearly observed within the LC-PUFAs eicosapentaenoic acid (EPA) and docosapentaenoic acid (DPA), but not with docosahexaenoic acid (DHA), suggesting that H. tuberculata is able to synthesize the former FAs fromtheir precursors. This pattern was also observed with arachidonic acid (ARA). In general abalone is able to synthesize and accumulate the necessary fatty acids to sustain growth at a wide range of temperatures and dietary sources, especially at lower temperatures, that could mean that this species is able to cope with a broad range of environmental conditions. However, DHA requirement in the H. tuberculata seems to be much inferior than previously reported, and its biosynthesis is undetectable under the present experimental conditions.