Is the Fatty Acid Composition of Freshwater Zoobenthic Invertebrates Controlled by Phylogenetic or Trophic Factors?

Abstract

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., fish. The content and ratios of these FA varied significantly in the studied zoobenthic species, consequently, the invertebrates were of different nutritional quality for fish. Eulimnogammarus viridis (Crustacea) and Dendrocoelopsis sp. (Turbellaria) had the highest nutrition value for fish concerning the content of EPA and DHA and n-3/n-6 and DHA/ARA ratios. Using canonical correspondence analysis we compared the FA profiles of species of the studied taxa taking into account their feeding strategies and habitats. We gained evidence that feeding strategy is of importance to determine fatty acid profiles of zoobenthic species. However, the phylogenetic position of the zoobenthic species is also responsible and may result in a similar fatty acid composition even if species or populations inhabit different water bodies or have different feeding strategies.

The role of water bugs (Heteroptera) as a potential source of essential polyunsaturated fatty acids for terrestrial consumers in steppe and forest-steppe

“…The EPA content per unit mass of adult water bugs and larvae was, in general, comparable to that in other groups of amphibiotic insects with complete meta morphosis [5][6][7][8]. In contrast to EPA, the content of DHA in water bugs of the genera Sigara and Para corixa was maximal among the values known for amphibiotic insects.…”

“…Apparently, the amount of PUFAs transferred to the land in differ ent climatic zones and landscapes is determined by the amount of the biomass of insects emerged per year and the content of PUFAs at the adult stage. It is known that the fatty acid composition of aquatic inverte brates, including the content of PUFAs, is largely determined by their phylogenetic affiliation [5].The fatty acid composition of the members of the order of insects with complete metamorphosis, such as Diptera, Trichoptera, Ephemeroptera, and Odonata has been studied in most detail [6][7][8]. These taxo nomic groups of amphibiotic insects bring to the land significant amounts of EPA, whereas the content of DHA in them is negligible.…”

“…The collection and primary process ing of the samples of water bugs for the analysis of the fatty acid composition, moisture, and organic carbon content were performed as described previously for samples of dragonflies and mosquitoes [6,7]. The analysis of fatty acids by gas chromatography-mass spectrometry was described in detail in [5]. The calcu lations of the mean values and standard deviations, analysis of variance, Fisher's least significant differ ence (LSD) test, and discriminant analysis were per formed using the Statistica 9.0 program package (Stat Soft Inc., United States).…”

“…For example, the content of DHA in the members of the family Corixidae 2-4 times exceeded that in species Odonata, Plecoptera, Thich optera, Ephemeroptera, Chironomidae, and Culicidae (0.02-0.11 mg per gram wet weight) ( Table 2). According to some data, the high content of DHA in tissues may be due to the predatory type of foraging of animals [5]. However, despite the fact that the stud ied species of the family Corixidae were omnivores [10], they contained significantly more DHA than the obligately predatory water bugs of the families Notonectidae and Naucoridae (Table 2).…”

Comparison of fatty acids profile and antioxidant enzyme level of cladoceran Moina brachiata (jurine, 1820) from freshwater bodies of Chennai

“…Methyl ethers of fatty acids (FAMEs) were analyzed and identified using a Gas Chromato Graph-Mass Spectrometer (JEOL GCMATE II GC-MS, Agilent Technologies 6890N Network GC system for Gas Chromatography, SAIF, IIT-Madras, Chennai). The conditions are described in detail elsewhere [19].Peaks of FAMEs were identified by their retention time and mass spectra in comparison to those in the database (Agilent Technologies, IIT Madras) and to those of available authentic standards (Sigma, United States). The quantification of fatty acids was calculated according to the peak area of an internal standard.…”