The nutritional diversity of resources can affect the adaptive evolution of consumer metabolism and consumer diversification. The omega-3 long-chain polyunsaturated fatty acids eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) have a high potential to affect consumer fitness, through their widespread effects on reproduction, growth, and survival. However, few studies consider the evolution of fatty acid metabolism within an ecological context. In the paper associated with this dataset, we document the extensive diversity in both primary producer and consumer fatty acid distributions among major ecosystems, between habitats, and among species within habitats. This dataset on fatty acid composition on primary producers and consumers from marine, freshwater, and terrestrial ecosystems is used to create Figure 2 in the paper. The data consists of alpha linolenic acid (ALA; 18:3n-3), EPA, and DHA as percent of total fatty acids.

We synthesized data on the fatty acid composition of primary producers and consumers from marine, freshwater, and terrestrial ecosystems. We collected data presented as percent or fraction of total fatty acids because this was the most commonly reported form of data and we focused on collecting data on ALA, EPA, and DHA because these three n-3 LCPUFA were the main compounds of interest to us. We used data from several previously published meta-analyses (Rumpold et al. 2013; Galloway and Winder 2015; Hixson et al. 2015; Hixson et al. 2016; Guil-Guerrero and Torija-Isasa 2016; Twining et al. 2016; Colombo et al. 2017; Ishikawa et al. 2019) as well as numerous additional recent studies covering additional taxa, such as birds, bats, and aquatic insects, with limited representation in previous meta-analyses.

In our database, we present meta-data on the meta-analysis where we found the data, when applicable, and original study. Because several meta-analyses had major overlaps in original studies cited, we removed replicate studies from our database such that original studies were only represented once. While matching up studies in previous meta-analyses with original studies, we corrected any errors in author and/or taxonomic name spellings, in year of study, and in citations (i.e., first author only listed when a study had multiple authors). We removed several primary producer observations from previous meta-analyses because we either could not locate the original study or because the original cited study was on a different taxa from that provided in the database and we could not locate any studies from the same authors on the taxa in the database: Floreto et al. 1993 (from Hixson et al. 2016), Thompson et al. 2002 (from Hixson et al. 2016), Martins et al. 2007 (from Colombo et al. 2017), James et al. 2012 (from Colombo et al. 2017), James et al. 2013 (from Hixson et al. 2016), and Teoh et al. 2013 (from Colombo et al. 2017). We also excluded one observation on aphid fatty acid composition from the Colombo et al. 2017 dataset because we could not locate the original Environment Canada study.

We identified taxa to the lowest possible taxonomic level reported in original studies and then added additional data on Phylum, Class, Order, and Family. We also report the tissue analyzed based on information from original studies (e.g., blubber for marine mammals). We then categorized observations by ecosystem (i.e., marine, freshwater, and terrestrial) based upon information (e.g., reported ecosystem, habitat, or species) provided in original studies. When available within the original study, we reported data on habitat (e.g., pelagic or benthic), common name, and tissue sampled. We also corrected miss-citations in previously published meta-analyses and spelling errors in species names using the taxize package in R (Chamberlain et al. 2014). When multiple data points rather than means per taxa (e.g., species or lowest available taxonomic unit) per study were included in either meta-analyses or original studies, we took the mean values of ALA, EPA, DHA for each taxa reported.

For primary producers, we identified each observation to genus. If observations were not identifiable to the genus or species level, they were excluded from the dataset. We report genus-level averages, if multiple observations were available for a single genus. For consumers, we included data on either the whole organism, as was commonly reported for both invertebrates and fish, or one tissue per species/lowest taxonomic unit. When data on multiple tissues were presented, we selected either muscle tissue or adipose tissue based upon which was available in the original study. Data on the fatty acid composition of muscle tissue was more commonly presented in studies on birds and terrestrial mammals whereas most studies on marine mammals presented data on blubber. Some studies included data on consumers sampled multiple times over the year and/or at multiple age classes. In addition, data on both males and females were presented in some studies. Because we were primarily interested in inter-specific differences in fatty acid composition, we calculated means across seasons, sex, and age classes at the genus level or the lowest taxonomic resolution possible based upon taxonomic information provided in the original study.

References for Fatty Acid Database

https://paperpile.com/shared/IGegrQ