This study aims to provide a quantitative analysis of amino acids (AA) and fatty acids (FA) on samples of the Abarenicola
pusilla
Polychaeta , taken at different seasons along the year, and under three types of processing (eviscerated carcass, pressed cake, and the liquid remaining).
The results showed a clear seasonal difference, where essential nutrients significantly decreased in the winter. Regarding the essential fatty acids, the eicosapentaenoic acid (EPA) and arachidonic acid (ARA) resulted in a relationship close to 1. In comparison, docosahexaenoic acid (DHA) was absent in some extracts during winter.
At the same time, the highest protein values were observed in the spring and summer , while crude lipid values were the same, indicating that A. pusilla uses AAs more efficiently as energy source than lipids . Also, a significantly higher amount of free amino acids, essential (EAA) and non-essential (NEAA), were presented in winter.
The Polychaeta press cake was the product with the highest quality in terms of protein content and AA and FA composition, being a good source of functional amino acids LYS, GLU, GLY, ALA, and HIS. Also, the Polychaeta press cake would be a good source of EFA, such as EPA and ARA.
Finally, the conditions under which Polychaeta could be harvest and the type of extract recommended to produce a valuable additive for marine aquafeeds are also discussed. It is also proposed to study the culture possibilities into the integrated multitrophic aquaculture providing them the best possible conditions as spring and summer when the highest and most valuable nutrients are encountered.