Biochemical composition of three Tunisian silverside (fish) populations caught in open sea, lagoon and island coasts

Fatty acid and amino acid profiles were determined in three silverside populations caught in Tunisian waters Atherina boyeri (open sea), Atherina lagunae (lagoon) and Atherina sp. (island coasts). Saturated fatty acids reached in total lipids 43.54%, 36.96% in marine and 33.64% in insular silverside and A. lagunae, in which eicosapentaenoic acid, docosahexaenoic acid and linoleic acid were the prominent fatty acids. The n-3/n-6 index showed a significant level indicating a tendency to accumulate n-3 fatty acids in A. boyeri and A. lagunae and n-6 fatty acids in Atherina sp. Total amino acid content ranged from 528 to 588 mg/g crude protein, in which, glutamic acid was the most abundant. Methionine had the lowest essential amino acid score in A. boyeri and Atherina sp. (0.73 and 0.71, respectively)while tryptophan had the lowest in A. lagunae (0.07)