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Reference Category Journals
DOI 10.1007/s00027-014-0388-x
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Title (Primary) High variability in carbon and nitrogen isotopic discrimination of tropical freshwater invertebrates
Author de Carvalho, A.P.C.; Gücker, B.; Brauns, M.; Boëchat, I.G.
Journal Aquatic Sciences
Year 2015
Department FLOEK
Volume 77
Issue 2
Page From 307
Page To 314
Language englisch
Keywords Carbon and nitrogen fractionation; Stable isotopes; Riverine food webs
UFZ wide themes RU2;
Abstract Stable isotope techniques are widely applied in aquatic food web research to infer trophic position or to estimate the relative contributions of different dietary resources. The accurate consideration of carbon (C) and nitrogen (N) discrimination in organisms is a critical prerequisite for such studies. Isotopic discrimination of invertebrates may differ systematically between temperate and tropical freshwater environments, but there are little data available on discrimination factors of tropical invertebrates. Here, we analyzed the C (Δ13C) and N discrimination (Δ15N) of eight taxa of benthic freshwater invertebrates from a Southeastern Brazilian tropical catchment, six predator and two shredder species. Predators showed a high variability in Δ13C (−1.5 to 1.3; min–max), but shredders exhibited a lower variability and had negative Δ13C values (−2.1 to −1.8). Values of Δ15N were also highly variable among both predators and shredders, but shredders had negative and lower values (−0.9 to −0.1) than predators (0.0 to 9.1). Tissue turnover rates were equal to or higher than 0.02 d−1 for all invertebrates, suggesting that experiment durations of 50 days may be sufficient for future isotopic discrimination experiments with tropical freshwater invertebrates. Our results suggest that Δ13C enrichment, and to a minor degree also Δ15N enrichment, may not always occur in tropical freshwater invertebrates.
Persistent UFZ Identifier
de Carvalho, A.P.C., Gücker, B., Brauns, M., Boëchat, I.G. (2015):
High variability in carbon and nitrogen isotopic discrimination of tropical freshwater invertebrates
Aquat. Sci. 77 (2), 307 - 314