title: The significance of linoleic acid in food sources for detritivorous benthic invertebrates.
abstract: Chemical composition of organic matter (OM) is a key driver for detritus consumption by macroinvertebrates and polyunsaturated fatty acid (PUFA) content is considered a candidate indicator of food palatability. Since traditionally used complex natural OM covaries in many quality attributes, it remains uncertain whether benthic invertebrates developed an actual preference for PUFA-rich food. Therefore we aimed to test the influence of the PUFA linoleic acid on OM consumption by aquatic macroinvertebrates using standardized surrogate substrates (decomposition and consumption tablet, DECOTAB) with added linoleic acid (PUFA) in comparison to consumption of DECOTAB containing only cellulose (Standard) or ground macrophytes (Plant). In microcosms, we observed a higher consumption rate of PUFA DECOTAB in comparison to Standard DECOTAB in two functionally distinct invertebrate species (Lumbriculus variegatus and Asellus aquaticus). This effect appeared to be overruled in the field due to unknown sources of natural variation. Although we observed higher consumption rates in species-rich ditches compared to species-poor ditches, consumption rates were comparable for all three types of DECOTAB deployed. Upon reduced food quality and palatability, results presented here hint that PUFA like linoleic acid may be a key OM attribute driving the performance of benthic macroinvertebrates and inherent functioning of aquatic ecosystems.
authors: Department of Aquatic Environmental Ecology, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands.
authors: J Arie
authors: JA
authors: Vonk
authors: Department of Aquatic Environmental Ecology, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands.
authors: Bernd F
authors: BF
authors: van Kuijk
authors: Department of Aquatic Environmental Ecology, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands.
authors: Mick
authors: M
authors: van Beusekom
authors: Institute of Environmental Sciences (CML), Leiden University, PO Box 9518, 2300 RA Leiden, The Netherlands.
authors: Ellard R
authors: ER
authors: Hunting
authors: Department of Aquatic Environmental Ecology, Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Sciencepark 904, 1098 XH Amsterdam, The Netherlands.
authors: Michiel H S
authors: MH
authors: Kraak
mesh_terms: D000818:Animals; D004032:Diet; D017753:Ecosystem; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D005504:Food Analysis; D005518:Food Preferences; D033321:Isopoda / Q000378:metabolism*; D019787:Linoleic Acid / Q000032:analysis*; D009835:Oligochaeta / Q000378:metabolism*
chemical_list: D005231:Fatty Acids, Unsaturated; D019787:Linoleic Acid