Assessing the utility of eDNA as a tool to survey reef-fish communities in the Red Sea

Relatively small volumes of water may contain sufficient environmental DNA (eDNA) to detect target aquatic organisms via genetic sequencing. We therefore assessed the utility of eDNA to document the diversity of coral reef fishes in the central Red Sea. DNA from seawater samples was extracted, amplified using fish-specific 16S mitochondrial DNA primers, and sequenced using a metabarcoding workflow. DNA sequences were assigned to taxa using available genetic repositories or custom genetic databases generated from reference fishes. Our approach revealed a diversity of conspicuous, cryptobenthic, and commercially relevant reef fish at the genus level, with select genera in the family Labridae over-represented. Our approach, however, failed to capture a significant fraction of the fish fauna known to inhabit the Red Sea, which we attribute to limited spatial sampling, amplification stochasticity, and an apparent lack of sequencing depth. Given an increase in fish species descriptions, comple...极少量的水体即可携带足量的环境DNA（environmental DNA，简称eDNA），借助基因测序技术即可检出目标水生生物。为此，本研究评估了eDNA在记录红海中部珊瑚礁鱼类多样性方面的应用潜力。研究人员对海水样本中的DNA进行提取，采用鱼类特异性16S线粒体DNA引物完成扩增，并通过宏条形码（metabarcoding）测序流程完成测序。随后，借助现有基因数据库或由参考鱼类构建的定制化基因数据库，将所得DNA序列比对至对应分类单元。本研究方法在属水平上检出了多种显眼的、隐秘底栖的以及具备商业价值的礁栖鱼类，其中隆头鱼科（Labridae）的部分类群出现过度代表的情况。但该方法未能覆盖红海已知鱼类区系中的相当一部分类群，我们将这一结果归因于空间采样范围有限、扩增随机性以及测序深度明显不足。鉴于鱼类物种描述数量的持续增长，完整[...]