Aurantiochytrium sp. and Nannochloropsis spp. meals as substitutes for fish oil in practical diets for Pacific white shrimp Penaeus vannamei

This study aimed to evaluate the use of microalgae meal (Aurantiochytrium sp. and Nannochloropsis spp.) as a substitute for fish oil in the diet of shrimp Penaeus vannamei reared in a clear water system. In the diet of these animals, the concentration of fish oil decreased as microalgae meal was inserted, and these were used in five different substitutions: 0, 25, 50, 75, and 100%. The treatments were carried out in triplicate, and after 49 days of cultivation, the zootechnical parameters and the composition of fatty acids in the animals' muscles were analyzed. In zootechnical performance, the shrimp obtained an average final weight of 16.59 ± 0.3 g, and the growth was approximately 1.89 ± 0.30 g week-1. In addition, feed conversion was, on average, 1.47 ± 0.28, and survival was greater than 97%. However, no significant difference was observed in these parameters. Regardless of the levels of fish oil replacement by microalgae meal, the composition of fatty acids in the shrimp muscle was ensured, as well as their quantity within groups, such as n-3 and n-6 polyunsaturated fatty acids. Thus, with the results obtained in the present study, it is suggested that it is possible to formulate a high-performance diet without any ingredients of marine origin (fish oil or fish meal), contributing to aquaculture's sustainability.