Influence of season and feeding intensity on the fatty acid composition of wild cobia (Rachycentron canadum, Linnaeus, 1766) in the Dungun coast, Malaysia
Cobia, Rachycentron canadum, is an important recreational marine fish of growing popularity in the aquaculture industry. Knowledge of the impact of environment on their fatty acids (FAs) utilization may contribute to the understanding their feeding in culture condition especially as cobia is been considered for low salinity culture. This study investigates the variations in the fatty acid contents of cobia from Dungun coast, Malaysia with respect to the changes in seasons and feeding intensity. Saturated fatty acids (FAs) comprised the majority of FAs in muscle, followed by monoenes, total poly-unsaturated fatty acids (PUFAs) (n-3) and then total PUFAs (n-6) with no seasonal variation in the quantity. A similar trend was observed in liver but total saturated FAs was significantly higher during the inter-monsoon while total monoenes significantly accumulate during monsoon. During low feeding intensity, there was a significant accumulation of PUFAs (n-6) in the muscle tissue (P < 0.05). Gut content analyses showed that cobia significantly increased the consumption of mollusks during the inter-monsoon (P < 0.05), although bony fishes dominated their diet throughout the year with no significant seasonal differences (P > 0.05). Our results suggest that cobia lipids are composed of a significant quantity of omega-3 and omega-6 FAs, which are considered to have important health benefits. While the environmental variability especially salinity fluctuations and prey abundance that accompany seasonal changes have a significant impact on the nutritional composition of cobia in Malaysian waters, their nutritional quality is maintained.