The decline in wild fish populations requires more intensive development of fish farms and the search for new nutritious feeds for artificial cultivation of seafood. Scientists evaluated the use of fly larvae grown on a mixture with the addition of camelina oil as one of the feed components in aquaculture. Such an additive increases the amount of polyunsaturated fatty acids in the larvae, which will be transferred to the fish eating it and make it healthier. The results of the study were published in the Journal of the Siberian Federal University. Biology.

The harvesting of wild fish on an industrial scale has reached its limits. Further intensive fishing may become an environmental disaster. In contrast, aquaculture, namely, fish breeding in artificial conditions, is rapidly developing. However, aquaculture feeds are often based on wild fish as well. Fish farming consumes up to 75% of the extracted fish oil. For further development of this industry, it is necessary to develop feeds made from other raw materials. In particular, insects can become a source for them. However, their fatty acid composition does not often meet the necessary requirements.
A team of Krasnoyarsk scientists from the Federal Research Center "Krasnoyarsk Science Center SB RAS” and SibFU raised larvae of green blowflies Lucilia sericata suitable for application in aquaculture feed. The larvae raised on supplemented feed contained a large amount of polyunsaturated fatty acids and had a rich aminoacid composition.

One of the most important components of fish feed is omega-3 polyunsaturated fatty acids, in particular, docosahexaenoic and eicosapentaenoic acids. They are necessary for the normal growth and development of fish and determine its high nutritional value. The researchers tried to find a fatty acid composition of fly feed that would provide enough omega-3 PUFA to make it a nutritious fish feed. Experts studied the composition and content of fatty acids in the larvae of the green blowfly Lucilia sericata, grown on a standard feed from poultry waste and feed with the addition of camelina oil rich in alpha-linolenic acid.

“Increased demand for quality wild fish feed for aquaculture leads to a reduction in the number of wild fish and to an increase in the cost of such feed. As a result, the cost of fish produced is sometimes more than half determined by the cost of feed. Further growth in the volume of products grown in aquaculture is possible with partial or complete replacement of some feed components. Insects can be one of those options. Additional positive factors include the absence of a negative effect of feed from insect larvae on the gastrointestinal tract of fish. Excessive use of herbal supplements can directly be harmful by provoking inflammatory processes. In addition, insect larvae can be grown year-round and require less land and water than other protein and lipid supplements. Since the fatty acid composition of the larvae can be modified, and the amino acid profile, with the exception of methionine, corresponds to the optimum parameters, we believe that the larvae of the green blowfly Lucilia sericata can be considered as one of the feed components for aquaculture, ” presented the results of the study, Doctor of Biology, Professor, Olesya Makhutova, Leading Researcher at the Institute of Biophysics SB RAS.

Comprehensive studies of the nutritional value of various inhabitants of water bodies, development of the foundations for modern aquaculture are priority topics for scientists from the Institute of Biophysics SB RAS. Previously, they studied the characteristics of the fatty acid composition of fish from the Yenisei River, discovered one of the most valuable fish in the world in terms of PUFA content in the north of the Krasnoyarsk Region, and initiated a project to breed it in aquaculture.

“Production of feed for aquaculture is a matter of industrial safety, where until recently we have been heavily dependent on imports. Since the quality of feed directly affects the value of the product obtained in aquaculture, such technologies can be classified as critical for public health. On the one hand, we focus on local, extremely valuable species of northern fish. On the other hand, given the impossibility of our Siberian ecosystems to provide high catches, it is better to move on to artificial cultivation. This requires their own, inexpensive and biochemically valuable feeds. Now we are looking at different options for supplements. The study mentioned above is one of the stages of prospective work aimed at ensuring our food sefety,” said Mikhail Gladyshev, Corresponding Member of RAS, Head of the Laboratory at the Institute of Biophysics SB RAS.

The work was supported by the Krasnoyarsk Regional Science Foundation within the framework of the project "Development of import-substituting technologies for aquaculture of salmon fish in the conditions of the Krasnoyarsk Region", which is implemented jointly with specialists from the Krasnoyarsk State Agrarian University.