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.

氮与碳的稳定同位素（δ¹⁵N和δ¹³C）是食物网生态学领域的重要研究工具，可用于确定消费者的食性与营养级位置。该方法得以恰当且可靠应用的核心前提之一，是使用物种特异性营养富集因子（trophic enrichment factors, TEFs，又称食性-组织判别因子（diet-tissue discrimination factors, DTDFs））。本研究针对水生甲壳类的碳、氮TEFs汇编了一份最新的综合数据集，所有数据均来自已发表文献。具体而言，2022年9月20日，研究团队通过多检索标准，在ISI Web of Science与Scopus两大在线数据库中开展文献检索，检索关键词组合为“trophic enrichment factor”或“discrimination factor”，同时搭配“stable isotopes”与“crustacean”。此外，本研究补充了使用相同关键词在Google Scholar（https://scholar.google.com/）中检索得到的结果，并通过免费软件Harzings’s Publish or Perish ver. 7.27.284953完成结果保存。本次文献检索共获取564条条目；随后，研究人员对这些条目的标题与摘要进行筛选，剔除了未以水生甲壳类物种为研究对象，或针对血液样本估算TEFs值的野外调查与实验室研究。对剩余87篇文献的全文进行详细审阅后，筛选出至少明确报告了氮同位素相关TEFs或DTDFs，且包含消费者与食物资源的分类学信息、消费者生活史阶段、分析所用组织样本、脂质提取处理方式、实验持续时长与实验温度的文献。最终纳入23篇符合上述标准的文献，发表时间跨度为1978年至2019年。本数据集收录于表1，其中除TEFs数值外，还包含文献来源、消费者与猎物物种的学名或通用名、生境信息（M代表海洋，F代表淡水）、物种生活史阶段信息、分析的组织样本、脂质提取处理方式（N代表未处理；Y代表化学提取或数学归一化）、实验持续时长（单位：天）与实验温度（单位：℃），以及食物的类型与同位素值（δ¹³C和δ¹⁵N）。表2则列示了本次数据提取所使用的文献的补充信息，若存在永久标识符（文献引用DOI）也将一并给出。