Effect of Greater Duckweed Spirodela polyrhiza Supplemented Feed on Growth Performance, Digestive Enzymes, Amino and Fatty Acid Profiles, and Expression of Genes Involved in Fatty Acid Biosynthesis of Juvenile Common Carp Cyprinus carpio

The greater duckweed Spirodela polyrhiza (Lemnaceae) is a free-floating freshwater macrophyte. effect of dietary inclusion in the feed common carp Cyprinus carpio fry was evaluated. control (SP0) contained soybean meal as primary protein source. In four experimental feeds, incorporated at levels 5% (SP5), 10% (SP10), 15% (SP15), and 20% (SP20) replacing meal. Broken-line regression showed that incorporation 10 13.4% were breakpoint for final weight specific growth rate (SGR) fish, respectively. SGR fed diet SP20 significantly higher compared with those others. conversion ratio lowest treatment. fish feeds linear relationships amylase, trypsin, chymotrypsin, lipase activities. content crude SP10, SP15, treatments Significantly lipid ash contents found diet-fed other fish. essential amino acids composition similar five different supplemented influenced fatty acid monounsaturated (MUFA) an inverse relationship level feed. highest MUFA SP0 diet. linoleic n-3 PUFA increasing trend duckweed, A expression fas SP5 fads2d6 SP10 expressions elovl2 elovl5 SP5, SP15 diets improved performance nutritional value carp.