An updated dataset of published carbon and nitrogen trophic enrichment factors (Δ13C and Δ15N) for aquatic crustacean taxa

Stable isotopes of nitrogen and carbon (δ15N and δ13C) represent an important tool in food web ecology, useful for the determination of consumers’ diet and trophic position. One of the key requirements for an appropriate and reliable use of this methodology is represented by the application of species-specific trophic enrichment factors (TEFs, also defined as diet-tissue discrimination factors, DTDFs). Here we present an updated synthesis of carbon and nitrogen TEFs for aquatic crustaceans collated from literature sources. Specifically, on September 20th, 2022 the online databases ISI Web of Science and Scopus were searched for publications by a multiple search criterion using the terms “trophic enrichment factor” or “discrimination factor” in conjunction with “stable isotopes” and “crustacean”. The results were complemented with those obtained from queries on Google Scholar (https://scholar.google.com/) using identical keywords and subsequently saved using the freeware Harzings’s Publish or Perish ver. 7.27.284953. The literature search resulted in a total of 564 entries; subsequently, their titles and abstracts were screened in order to remove field investigations and laboratory studies not performed on aquatic crustacean species or estimating TEFs values on blood. The full text of the remaining 87 sources was examined in detail to select those where TEFs or DTDFs were reported explicitly at least for nitrogen, together with information on the taxonomy of the consumer and dietary resource, the consumer life stage, the analysed tissues, lipid extraction treatment, duration and temperature at which the experiment was performed. 23 eligible literature sources matching the aforementioned criteria were eventually selected, published between 1978 and 2019. The dataset is contained in Table 1; it includes, together with TEFs values, the literature source, the consumer and prey species scientific or common names, information on the environment (M = marine, F = Freshwater), information on the species life stage, the analysed tissue, the treatment used for lipids extraction (N = no treatment; Y = chemical extraction or mathematical normalization), the duration (in days) and temperature at which the experiment was performed (in °C), and the type and the isotopic values of the diet (δ13C and δ15N). complementary information regarding the the literature sources used to extract the data including permanent identifiers (bibliographic Citation DOI) if available are reported in Table 2.