oa Biogeochemistry of the Digestive System of Antarctic Krill, Euphausia Superba – A Lipidomic and Metabolomic Study

Antarctic krill (Euphausia superba), with an estimated biomass of 379 million tonnes, the largest biomass of a wild living animal, is a key species in the Southern Ocean ecosystem. Krill is acting as a direct link from primary/secondary producers to top predators and play a central role in biogeochemical cycles by exporting carbon outside the euphotic zone via the excretion of faecal pellets. In this context, the collective digestive systems of Antarctic krill can be considered one of the largest bioreactors on Earth for the processing of organic material. Transcriptomic-proteomic and metagenomic studies of the digestive system of Antarctic krill have already revealed its enormous metabolic potential. This study presents the first comprehensive overview of the lipidome and metabolome of the digestive system of Antarctic krill. It thus makes an important contribution to understanding the biogeochemical processes in this bioreactor, which plays a key role in the carbon cycle of the Southern Ocean. Future studies should use the same approach to investigate the composition of ingested food and excreted faecal pellets in order to gain a holistic understanding of the turnover of biomass in the Southern Ocean and the export of carbon driven by E. superba.