Fatty Acids of Sestonic Lipid Classes as a Tool to Study Nutrition Spectra of Rotifers and Ciliates in a Siberian Eutrophic Reservoir

Abstract

Fatty acid composition of triacylglycerols (TAG) and polar lipids (PL) of seston from the Siberian Reservoir Bugach was analyzed to reveal the spectra of nutrition of micro- and mesozooplankton (protozoa and rotifers). The seasonal changes of micro- and mesozooplankton nutrition were observed. Bacteria comprised relatively constant part in feeding protozoa and rotifers during the whole vegetation season. The maximum consumption of higher plants detritus occurred at the beginning of August. Phytoplankton was consumed more intensively in spring during the rapid growth of diatoms (Stephanodiscus sp.) and from the middle to the end of June when cyanobacteria (Anabaena flos-aquae, Aphanizomenon flos-aquae, Planktothrix agardhii), dynophytes (Peridinium sp.) euglenas (Euglena proxima) and diatoms (Stephanodiscus sp.) were dominated in Bugach Reservoir. The dominant species of protozoa differed in their nutrition spectra: Holophrya sp. was feeding on diatoms in spring and bacteria in the middle of summer; Tintinidium sp. was consuming diatoms and cyanobacteria; Nassula picta was feeding on cyanobacteria.