Fig. 3: Detected archaeal intact polar lipids (IPLs) in nanograms per liter (green stars) in the Black Sea water column, and predicted archaeal IPLs (shaded area) considering different estimates of membrane lipid production and cell size for the archaeal groups found.

Total archaeal cells and Ca. Cloacimonetes cells per liter based on qPCR and amplicon sequencing data are also indicated. All calculations are available in Supplementary File 1.