Metabarcoding and metabolome analyses of copepod grazing reveal feeding preference and linkage to metabolite classes in dynamic microbial plankton communities

Jessica L. Ray, Julia Althammer, Katrine S. Skaar, Paolo Simonelli, Aud Larsen, Diane Stoecker, Andrey Sazhin, Umer Z. Ijaz, Christopher Quince, Jens C. Nejstgaard, Marc Frischer, Georg Pohnert, Christofer Troedsson

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)

Abstract

In order to characterize copepod feeding in relation to microbial plankton community dynamics, we combined metabarcoding and metabolome analyses during a 22-day seawater mesocosm experiment. Nutrient amendment of mesocosms promoted the development of haptophyte (Phaeocystis pouchetii)- and diatom (Skeletonema marinoi)-dominated plankton communities in mesocosms, in which Calanus sp. copepods were incubated for 24 h in flow-through chambers to allow access to prey particles (<500 μm). Copepods and mesocosm water sampled six times spanning the experiment were analysed using metabarcoding, while intracellular metabolite profiles of mesocosm plankton communities were generated for all experimental days. Taxon-specific metabarcoding ratios (ratio of consumed prey to available prey in the surrounding seawater) revealed diverse and dynamic copepod feeding selection, with positive selection on large diatoms, heterotrophic nanoflagellates and fungi, while smaller phytoplankton, including P. pouchetii, were passively consumed or even negatively selected according to our indicator. Our analysis of the relationship between Calanus grazing ratios and intracellular metabolite profiles indicates the importance of carbohydrates and lipids in plankton succession and copepod–prey interactions. This molecular characterization of Calanus sp. grazing therefore provides new evidence for selective feeding in mixed plankton assemblages and corroborates previous findings that copepod grazing may be coupled to the developmental and metabolic stage of the entire prey community rather than to individual prey abundances.

Original languageEnglish
Pages (from-to)5585-5602
Number of pages18
JournalMolecular Ecology
Volume25
Issue number21
DOIs
Publication statusPublished - 1 Nov 2016

Keywords

  • Calanus grazing
  • eukaryote V7 SSU
  • metabarcoding
  • metabolome profiling
  • Phaeocystis pouchetii
  • seawater mesocosms
  • Skeletonema marinoi
  • symbiosis

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