Influence of feeding regime on fatty acid composition in young red-spotted grouper Epinephelus akaara

Abstract

ABSTRACT: Young red-spotted grouper Epinephelus akaara with an average total length of 3.4 cm were divided into five groups in floating net-cages, and reared under satiated conditions with different feeding frequencies (0.5, 1, 2, 4 and 8 times per day) for 40 days. Total food intake increased with feeding frequency. Feeding four times per day resulted in the highest growth and food conversion efficiency. Total lipid accumulation in the muscle, liver and intraperitoneal fat body (IPF) increased with feeding frequency. Red-spotted grouper were found to contain a high proportion of docosahexaenoic acid (DHA) in the muscle. Fish fed 0.5 times per day were characterized as having a high proportion of DHA in triglycerides (TG) in muscle (80%), liver (69%) and IPF (18%). Increasing saturated fatty acids and a relative reduction of DHA were observed in the muscle TG as the feeding frequency increased. Frequent feeding accelerated the accumulation of eicosapentaenoic acid and saturated acids in the liver and IPF. Low saturated acids and a subsidiary proportional increase in DHA were the result of the low lipid reserves. A possible role for DHA and saturated acids are discussed with regard to lipid reserves.