Study of body composition, lipid and fatty acid profile during larval development in Caspian Sea carp (Cyprinus carpio).
This study was aimed to gain knowledge on ontogeny of lipid and fatty acid profile in feral carp larvae and to determine nutritional requirements with a view to improving product quality. Real-time fatty acid profile was investigated in 1-33 day old larvae of Cyprinus carpio. This study was carried out at the governmental warm water fish aquaculture center of Shahid Rajaee in Sari, Mazandaran, Iran. Cyprinus carpio larvae obtained from breeders captured in an estuarine environment were analyzed for lipid/fatty acid composition. Feeding with rotifer started from day 3 to day 7 and then larvae were fed with dry diet from day 8 onwards. Decreased total lipid and fatty acid profile alterations indicated energy-directed preferential metabolism of studied nutrients within certain intervals. During early larval stages, reduced monounsaturated fatty acids showed that these fatty acids were utilized as an energy source (p<0.05). Increased contents of docosahexaenoic acid and eicosapentaenoic acid well proved that these polyunsaturated fatty acids were not energy-generating substrates (p<0.05) instead, were preserved as structural components for physiological processes. Marine carp larvae apparently metabolized dietary linolenic acid to eicosapentaenoic acid and docosahexaenoic acid and dietary linoleic acid to Arachidonic acid. Arachidonic acid was clearly insignificantly utilized (p>0.05). The percentage of body protein andash increased with body weight but percentage of body lipid and moisture decreased.