The effects of seasons and different feeds on fatty acid composition in fillets of cultured gilthead sea bream (Sparus aurata L.) and European sea bass (Dicentrarchus labrax L.) in Turkey

Abstract

Dietary and seasonal effects on the fatty acid composition in the fillets of sea bream Sparus aurata and sea bass Dicentrarchus labrax were studied. Samples of the fish and feed were taken at 4 fish farms on the Aegean coast of Turkey during the summer, winter and spring seasons of 2004. The 2 commercial pelleted feeds (A and C) and 2 commercial extruded feeds (B and D) used in the fish farms were analyzed. There were not significant differences among the seasonally fatty acid composition in feed and fish samples except for MUFA (monounsaturated fatty acid) in the fillets of sea bream. Sea bream fillets had significantly higher total MUFA concentration in winter samples (33.5 +/- 1.40%) than summer (32.0 +/- 0.37%) and spring (31.8 +/- 0.87%) samples (P < 0,05). Predominant fatty acids of all feeds and fish fillets were 14:0, 16:0. 18:0. 16:1n-7, 18:1n-9. 18:2n-6, 20:5n-3 (eicosapentaenoic acid, EPA) and 22:6n-3 (docosahexaenoic acid, DHA). The feeds generally had ArA (arachidonic acid) level ranging from 0.6% to 0.9% of the total fatty acids. Fatty acid composition in fish fillets generally reflected the fatty acid composition of the feeds. The changes in fatty acid composition of the fillets indicate that the MUFA were probably dispensable for sea bream and sea bass. EPA, DHA and ArA levels in the commercial feeds were adequate for both fish species. The results of this study indicated that both fish species were as a good source of n-3 HUFA in different seasons.