Comparative characteristics of the size-mass parameters and lipid composition of wild and cultured eggs of the muksun Coregonus muksun (Pallas, 1814)
A. A. Lyutikov
Saint Petersburg Branch of the Russian Federal Research Institute of Fisheries and Oceanography (GosNIORKH named after L. S. Berg), Saint Petersburg, Russia
Keywords: muksun, eggs, fatty acid composition, n atural populations, cultivated mature fish
Abstract
Comparative analysis of the size-mass and biochemical parameters (total lipid content and their fractional and fatty acid composition) of eggs of wild and cultured producers of the Ob muksun showed significant differences between them. Wild eggs is characterized by smaller size (by 7 %) and weight (by 15 %), higher fat content (by 13 %) and the level of diacylglycerols (by 33 %), and lower phospholipid content (by 30 %) in comparison with factory eggs. At the same time, factory eggs differs from wild eggs by a higher level of physiologically significant docosahexaenoic 22:6n-3 (1.8 times) and linoleic 18:2n-6 (7.1 times) acids, but a relatively lower level of eicosapentaenoic 20:5n-3 (in 1.5 times) and arachidonic 20:4n-6 (4.2 times), respectively. Such changes in the fatty acid status led to a decrease in the commercial eggs of n-3/n-6 ratio (by 52 %), palmitic 16:0/ oleic 18:1n-9 (32 %) and α-linolenic 18:3n-3/18:2n-6 (by 45 %), and to an increase of 22:6n-3/20:5n-3 (by 63 %). In addition, in the eggs of factory muksun, 68 % of the total lipids are 4 acids - 16:0, 18:1n-9, 22:6n-3 and 18:2n-6, in wild eggs the share of these acids was 47 %. The established differences in the size-mass parameters, the total lipid content and their fractional and fatty acid composition of wild and hatchery eggs of the Ob muksun are most likely associated with a different diet and habitat conditions of the sexually mature fish in captivity and nature.
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