Data from: 18S rRNA V9 metabarcoding for diet characterization: a critical evaluation with two sympatric zooplanktivorous fish species

The potential of the 18S rRNA V9 metabarcoding approach for diet assessment was explored using MiSeq paired-end (PE; 2 × 150 bp) technology. To critically evaluate the method′s performance with degraded/digested DNA, the diets of two zooplanktivorous fish species from the Bay of Biscay, European sardine (Sardina pilchardus) and European sprat (Sprattus sprattus), were analysed. The taxonomic resolution and quantitative potential of the 18S V9 metabarcoding was first assessed both in silico and with mock and field plankton samples. Our method was capable of discriminating species within the reference database in a reliable way providing there was at least one variable position in the 18S V9 region. Furthermore, it successfully discriminated diet between both fish species, including habitat and diel differences among sardines, overcoming some of the limitations of traditional visual-based diet analysis methods. The high sensitivity and semi-quantitative nature of the 18S V9 metabarcoding approach was supported by both visual microscopy and qPCR-based results. This molecular approach provides an alternative cost and time effective tool for food-web analysis.

本研究采用MiSeq双端（Paired-End，PE；2×150 bp）测序技术，探究了18S核糖体RNA V9高变区元条形码（18S rRNA V9 metabarcoding）技术在食性评估中的应用潜力。为严谨评估该方法对降解/消化后DNA的检测性能，本研究对采自比斯开湾的两种浮游动物食性鱼类——欧洲沙丁鱼（Sardina pilchardus）与欧洲黍鲱（Sprattus sprattus）的肠道食性进行了分析。本研究首先通过计算机模拟、模拟群落样本及野外浮游生物样本，对18S V9元条形码技术的分类分辨率与定量潜力进行了评估。当18S V9区域存在至少一个可变位点时，本方法可可靠地从参考数据库中区分出对应物种。此外，该技术可有效区分两种鱼类的食性差异，包括沙丁鱼的栖息地与昼夜摄食差异，弥补了传统视觉食性分析方法的部分局限。18S V9元条形码技术的高灵敏度与半定量特性，得到了显微观测与实时定量PCR（quantitative PCR，qPCR）结果的验证。该分子技术为食物网分析提供了一种兼具成本效益与时间效益的备选工具。