摘要: 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 (D13C) and N discrimination (D15N) 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 D13C (-1.5 to 1.3; min–max), but shredders exhibited a lower variability and had negative D13C values (-2.1 to-1.8). Values of D15N 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 D13C enrichment, and to a minor degree also D15N enrichment, may not always occur in tropical freshwater invertebrates.