Assessment of short-term spatio-temporal variability in the structure of mesozooplankton communities integrating microscopy and multigene high-throughput sequencing

Variability in composition and structure of the mesozooplankton communities in the Bay of Malaga (SW Mediterranean) were characterized during a 26 h cycle using an integrative taxonomic approach. We combined microscopic identification of organisms, with metabarcoding for the genes of the mitochondrial DNA COI and the V9 hypervariable region of the ribosomal RNA 18S. Richness and diversity obtained by microscopy were higher than those measured with COI, as COI did not detect some phyla. COI however allowed for the identification to species level of several taxa that were left at higher taxonomic rank under the microscope. 18S detected a wider range of taxa than COI and microscopy, although with lower taxonomic resolution. Differences between coastal-night and shelf-day zooplankton communities structure were detected by both microscopy and metabarcoding. The combination of these two approaches increased the known copepod species in the SW Mediterranean Sea by 9%. An integrative approach combining morphology and COI metabarcoding is proposed to further facilitate mesozooplankton biodiversity studies.

Automated summary

This study characterized the variability in composition and structure of mesozooplankton communities in the Bay of Malaga using an integrative taxonomic approach. The combination of microscopic identification and metabarcoding allowed for higher resolution in species identification and broader taxonomic coverage. Differences in zooplankton communities between coastal-night and shelf-day were detected using both microscopy and metabarcoding. The integrative approach increased the knowledge of copepod species in the Southwest Mediterranean Sea by 9%.