Spadefoot Pelobates vespertinus (Amphibia, Pelobatidae) as a transmitter of fatty acids from water to land in a forest-steppe floodplain.

The transfer of biomass and polyunsaturated fatty acids by the spadefoot P. vespertinus (previously subspecies of P. fuscus) from aquatic to terrestrial ecosystems was studied for five years in small floodplain water bodies of a forest-steppe zone.

Fatty Acid Composition and Contents of Fish of Genus from Natural Ecosystems and Aquaculture.

Fatty acids (FA) of muscle tissue of species and its forms, , , , and , from six Russian lakes and two aquacultures, were analyzed. Considerable variations in FA compositions and contents were found, including contents of eicosapentaenoic and docosahexaenoic acids (EPA and DHA), which are important indicators of fish nutritive value for humans. As found, contents of EPA+DHA (mg·g wet weight) in muscle tissue of species and forms varied more than tenfold.

Assessing the Reliability of Quantitative Fatty Acid Signature Analysis and Compound-Specific Isotope Analysis-Based Mixing Models for Trophic Studies.

The study of the trophic relationships of aquatic animals requires correct estimates of their diets. We compared the quantitative fatty acid signature analysis (QFASA) and the isotope-mixing model IsoError, based on the compound-specific isotope analysis of fatty acids (CSIA-FA), which are potentially effective models for quantitative diet estimations. In a 21-day experiment, was fed a mixture of two food items, and which were supplied in nearly equal proportions.

Transfer efficiency of carbon, nutrients, and polyunsaturated fatty acids in planktonic food webs under different environmental conditions.

The trophic transfer efficiency (TTE) is an important indicator of ecosystem functioning. However, TTE data from freshwater food webs are ambiguous due to differences in time scales and methods. We investigated the transfer of essential substances (carbon, nutrients, and polyunsaturated fatty acids) through plankton communities in 30 Polish lakes with different trophic status in the middle of summer.

Comparison of Fatty Acid Contents in Major Lipid Classes of Seven Salmonid Species from Siberian Arctic Lakes.

Long-chain omega-3 polyunsaturated fatty acids (LC-PUFA) essential for human nutrition are mostly obtained from wild-caught fish. To sustain the LC-PUFA supply from natural populations, one needs to know how environmental and intrinsic factors affect fish fatty acid (FA) profiles and contents. We studied seven Salmoniformes species from two arctic lakes.

Long-chain Omega-3 Polyunsaturated Fatty Acids in Natural Ecosystems and the Human Diet: Assumptions and Challenges.

Over the past three decades, studies of essential biomolecules, long-chain polyunsaturated fatty acids of the omega-3 family (LC-PUFAs), namely eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), have made considerable progress, resulting in several important assumptions. However, new data, which continue to appear, challenge these assumptions. Based on the current literature, an attempt is made to reconsider the following assumptions: 1.

Fatty Acid Composition and Contents of Seven Commercial Fish Species of Genus Coregonus from Russian Subarctic Water Bodies.

In several Russian northern lakes and rivers, Arctic cisco Coregonus autumnalis, least cisco C. sardinella, peled C. peled, tugun C.

Export of aquatic productivity, including highly unsaturated fatty acids, to terrestrial ecosystems via Odonata.

Based on 31-year field study of the abundance and biomass of 18 species of odonates in the Barabinsk Forest-Steppe (Western Siberia, Russia), we quantified the contribution of odonates to the export of aquatic productivity to surrounding terrestrial landscape. Emergence varied from 0.8 to 4.

Triploidy does not decrease contents of eicosapentaenoic and docosahexaenoic acids in filets of pink salmon Oncorhynchus gorbuscha.

Triploid fish has become an important item of commercial aquaculture, but data on its fatty acid (FA) composition are still controversial, especially regarding essential polyunsaturated fatty acids, eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA). We studied FA composition and content of diploid and triploid pink salmon Oncorhynchus gorbuscha, reared in aquaculture in a bay of the White Sea (Russia). FA composition, measured as percentages of total FA of triploids and immature diploid females significantly differed from that of mature diploid fish.

Comparison of fatty acid contents and composition in major lipid classes of larvae and adults of mosquitoes (Diptera: Culicidae) from a steppe region.

Emerging aquatic insects, including mosquitoes, are known to transfer to terrestrial ecosystems specific essential biochemicals, such as polyunsaturated fatty acids (PUFA). We studied fatty acid (FA) composition and contents of dominant mosquito populations (Diptera: Culicidae), that is, Anopheles messeae, Ochlerotatus caspius, Oc. flavescens, Oc.

Fatty acid content and composition of sediments from Siberian eutrophic water bodies: implications for biodiesel production.

We studied lipids and fatty acids (FA) in bottom sediments from four Siberian water bodies, Bugach, Lesnoi and Krasnoyarsk freshwater reservoirs and brackish Shira lake, that differed in physico-chemical and biological conditions. We considered the potential of the bottom sediments as a feedstock for biodiesel production and estimated properties of the obtained biodiesel as a fuel on the basis of FA composition. Contents of lipids and FA in the sediments moderately varied and were generally close to the reported data from lacustrine and estuarine systems.

Production of EPA and DHA in aquatic ecosystems and their transfer to the land.

Most omnivorous animals, including humans, have to some degree relied on physiologically important polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from food. Only some taxa of microalgae, rather than higher plants can synthesize de novo high amounts of EPA and DHA. Once synthesized by microalgae, PUFA are transferred through trophic chain to organisms of higher levels.

Comparison of polyunsaturated fatty acids content in filets of anadromous and landlocked sockeye salmon Oncorhynchus nerka.

Fatty acid composition and content of 2 forms of sockeye salmon Oncorhynchus nerka from lakes in Kamchatka Peninsula (Russia) were compared. One form of sockeye salmon was anadromous ("marine"), that is, adult fish migrated in ocean to feed and grow and than return in the lake to breed. Fish of another form, kokanee, never migrate in the ocean.

Stable isotope composition of fatty acids in organisms of different trophic levels in the Yenisei River.

We studied four-link food chain, periphytic microalgae and water moss (producers), trichopteran larvae (consumers I), gammarids (omnivorous--consumers II) and Siberian grayling (consumers III) at a littoral site of the Yenisei River on the basis of three years monthly sampling. Analysis of bulk carbon stable isotopes and compound specific isotope analysis of fatty acids (FA) were done. As found, there was a gradual depletion in (13)C contents of fatty acids, including essential FA upward the food chain.

Is the fatty acid composition of freshwater zoobenthic invertebrates controlled by phylogenetic or trophic factors?

We studied the fatty acid (FA) content and composition of ten zoobenthic species of several taxonomic groups from different freshwater bodies. Special attention was paid to essential polyunsaturated fatty acids, eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), and arachidonic acid (ARA, 20:4n-6); and the n-3/n-6 and DHA/ARA ratios, which are important for consumers of higher trophic levels, i.e.

Efficiency of transfer of essential polyunsaturated fatty acids versus organic carbon from producers to consumers in a eutrophic reservoir.

One of the central paradigms of ecology is that only about 10% of organic carbon production of one trophic level is incorporated into new biomass of organisms of the next trophic level. Many of energy-yielding compounds of carbon are designated as 'essential', because they cannot be synthesized de novo by consumers and must be obtained with food, while they play important structural and regulatory functions. The question arises: are the essential compounds transferred through trophic chains with the same efficiency as bulk carbon? To answer this question, we measured gross primary production of phytoplankton and secondary production of zooplankton and content of organic carbon and essential polyunsaturated fatty acids of ω-3 family with 18-22 carbon atoms (PUFA) in the biomass of phytoplankton and zooplankton in a small eutrophic reservoir during two summers.

Content of essential polyunsaturated fatty acids in three canned fish species.

Three canned fish species--Pacific saury (Cololabis saira), Pacific herring (Clupea harengus) and Baltic sprat (Sprattus sprattus)--most common and popular in Russia, were analyzed for fatty acids. Special attention was paid to long-chain essential polyunsaturated fatty acids: eicosapentaenoic acid (20:5omega3) and docosahexaenoic acid (22:6omega3). Sums of eicosapentaenoic acid and docosahexaenoic acid in saury, herring and sprat were, on average, 2.