Studies on Lipids in Fresh-Water Fishes 7. Comparison of Lipid Components among Wild and Cultured Eel (Anguilla japonica), and Conger Eel (Astroconger myriaster)

This study was designed to compare the lipid components among wild and cultured eel, Anguilla japonica, and conger eel, Astroconger myriaster. The lipid components of cultured eel were analyzed and compared with those of wild and conger eel. In the content of total lipid, the lipid content in cultured eel was slightly higher than that in wild one, but 2 times higher than that in conger eel. The lipid contents in edible portion of wild and cultured eel were 5 times higher than those in viscera, but the lipid content in edible portion of conger eel showed a similar trend to that in viscera. In the fatty acid composition of neutral lipid in edible portion, percentages of in cultured eel were higher than those in wild one, while percentages of lower, and percentages of in conger eel were noticeably higher than those in wild and cultured eels. In the case of phospholipid in edible portion, percentages of in cultured eel were higher than those in wild one, while percentages of lower. The unsaturation (TUFA/TSFA) of neutral lipid was no significant difference among wild and cultured eel, and conger eel, but that of phospholipid in wild eel was higher than that in cultured eel and conger eel. The essential fatty acid content(TEFA) of neutral lipid in edible portion of wild eel was 3 times higher than that of cultured one. but the TEFA of phospholipid in edible portion was no significant difference among wild and cultured eels, and conger eel. The w3 highly unsaturated fatty acid content (w3 HUFA) of neutral lipid in edible portion of wild eel was 2.0 to 2.5 times higher than that of cultured eel and conger eel, but the w3 HUFA of phospholipid in edible portion of wild eel was noticeably higher than that of cultured eel and conger eel. In the ratio (A/B) of fatty acid content (A) in cultured eel to that (B) in diet, the A/B ratios of were 0.23 to 0.48 much lower than the other fatty acid. Consequently, it is considered that the ratios of w3 HUFA is related to the biosynthesis of polyenoic acid and growth rate of cultured eel.