Fatty acids differentiate consumers despite variation within prey fatty acid profiles

Austin Happel, Christopher Maier, Nicholas Farese, Sergiusz Czesny, Jacques Rinchard

Research output: Contribution to journalArticlepeer-review


Techniques that biochemically trace foraging habits of predators rely on the assumption that intra-specific variation in prey species is smaller than variation among them. At the same time, these techniques often show that diets can induce drastic changes in the biochemical profiles of prey species, especially across different ecosystems. We tested if intra-specific variation in fatty acid profiles of prey species added enough noise to confound quantitative fatty acid signature analysis (QFASA) using a controlled feeding experiment. Steelhead trout (Oncorhynchus mykiss) were fed either alewife (Alosa pseudoharengus) or round goby (Neogobius melanostomus) from either Lake Ontario or Cayuga Lake for a period of 8 weeks. Fatty acid profiles were significantly different between prey species and between lake of origin within each species. Differences in fatty acid profiles of steelhead trout strongly reflected prey species differences, whereas differences related to prey origin (lakes) were noted at a much lesser extent. QFASA performed remarkably well given the differences observed between the lakes prey originated from. Our results indicate that QFASA models for steelhead trout are probably not specific to one lake, and could provide estimates for other freshwater systems where alewife and round goby serve as the primary forage.

Original languageEnglish (US)
Pages (from-to)1416-1426
Number of pages11
JournalFreshwater Biology
Issue number8
StatePublished - Aug 2019


  • diets
  • fatty acid profile
  • feeding experiment
  • quantitative fatty acid signature analysis
  • trophic ecology

ASJC Scopus subject areas

  • Aquatic Science


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