Dietary fat concentrations influence fatty acid assimilation patterns in Atlantic pollock (Pollachius virens)

Philosophical Transactions of the Royal Society B: Biological Sciences
By: , and 

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Abstract

A key aspect in the use of fatty acids (FA) to estimate predator diets using Quantitative FA Signature Analysis (QFASA) is the ability to account for FA assimilation through the use of calibration coefficients (CC). Here, we tested the assumption that CC are independent of dietary fat concentrations by feeding Atlantic pollock (Pollachius virens) three formulated diets with very similar FA proportions but different fat concentrations (5 – 9 % of diet) for 20 weeks. CC calculated using FA profiles of diet and triacylglycerols in pollock liver were significantly different for the three diets. To test the robustness of diet estimates to these differences, we used the CC set derived from feeding the diet with the lowest fat concentration, published prey FA profiles and realistic diet estimates of pollock to construct ‘pseudo-predators’. Application of QFASA to each pseudo-predator using the three sets of CC and the same prey FA profiles resulted in diet estimate biases of 2-fold for major prey items and ~ 5-fold for minor prey items. This work illustrates the importance of incorporating diets with fat concentrations that are similar to natural prey when conducting feeding experiments to calculate CC.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Dietary fat concentrations influence fatty acid assimilation patterns in Atlantic pollock (Pollachius virens)
Series title Philosophical Transactions of the Royal Society B: Biological Sciences
DOI 10.1098/rstb.2019.0649
Volume 375
Issue 1804
Year Published 2020
Language English
Publisher Royal Society Publishing
Contributing office(s) Alaska Science Center Biology MFEB
Description 20190649, 9 p.
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