浮游动物是河口营养网络的关键组成部分。然而,常规监测受到基于形态学识别的困难的阻碍。基于DNA的方法使我们能够规避其中的一些障碍,提供精确的物种识别,无论研究者的分类学专业知识或标本的发育阶段。然而,该过程取决于参考库的完整性。在这项研究中,我们试图评估DNA元编码的潜力,以评估季节性(夏季,秋天,和早春)和浮游动物的空间动态(四个位置跨越约6公里)在利马河口(葡萄牙西北部)。使用了两个遗传标记:细胞色素c氧化酶亚基I和核糖体18SrRNA基因的V4高变区。总的来说,回收了327种,和两个标记显示分钟重叠(7%用两个标记检测)。物种丰富,composition,分类学差异主要受季节影响,从夏季开始呈下降趋势(独家物种数量最多,n=74)到弹簧。第二季,类群组成受到空间变异的影响,其中最下游的站点显示出最高数量的专有物种,n=53。共检测到16种非本地物种,但是在河口中只记录了一个(Austrominusmodestus)。总之,季节和空间梯度都影响了恢复的丰富度,composition,和分类学上的独特性,证实了DNA的巨大能力,可以提供更高密度的监测,并为复杂浮游动物群落的组成和动态提供新的思路。
Zooplankton are key components of estuarine trophic networks. However, routine monitoring is hindered by the difficulty of morphology-based identification. DNA-based methods allow us to circumvent some of these hurdles, providing precise species identifications regardless of the taxonomic expertise of the investigator or the developmental stage of the specimens. However, the process is dependent on the completeness of the reference libraries. In this study, we sought to evaluate the potential of DNA metabarcoding to assess the seasonal (summer, autumn, and early spring) and spatial dynamics of zooplankton (four locations spanning ca. 6 km) in the Lima estuary (NW Portugal). Two genetic markers were used: the cytochrome c oxidase subunit I and the V4 hypervariable region of the ribosomal 18S rRNA genes. Overall, 327 species were recovered, and both markers displayed minute overlap (7% were detected with both markers). Species richness, composition, and taxonomic distinctness were majorly influenced by the season, with a declining tendency from summer (highest number of exclusive species, n = 74) to spring. Second to season, the taxa composition was influenced by spatial variation where the most downstream site displayed the highest number of exclusive species, n = 53. A total of 16 non-indigenous species were detected using metabarcoding, but only one (Austrominus modestus) has been documented out in the estuary. In conclusion, both the seasonal and spatial gradients influenced the recovered richness, composition, and taxonomic distinctness, confirming the great aptitude of DNA metabarcoding for providing higher density monitoring and shedding new light on the composition and dynamics of complex zooplankton communities.