Use of Caviar and Fillet Biomarker Fatty Acids to Determine the Origin of Sterlet Acipenser ruthenus (Linnaeus, 1758).

Significant differences in the fatty acid (FA) composition of caviar and muscle tissue (fillet) were found in the sterlet Acipenser ruthenus (Linnaeus, 1758) between fish from the Yenisei River and aquaculture farms and were associated with different food sources. Caviar and muscle tissue of sterlet from the natural habitat showed significantly higher levels of the FAs that provide biomarkers of diatoms and bacterial matter. Oleic and linoleic acids, which are characteristic of higher plant oils, and long-chain monounsaturated fatty acids, which are biomarkers of marine copepods, displayed significantly higher contents in sterlet grown in aquaculture, apparently originating from artificial foods. A ratio of several biomarker FAs was for the first time proposed to assay, and its threshold value was established to determine whether sturgeon caviar and fillet originate from fish from natural habitats or aquaculture.