Position in a system
| system | Vitae - living organisms |
| domain | Bacteria (Haeckel, 1894) Woese, Kandler Wheelis, 1990 - bacterians |
| phylum | Cyanobacteria Stanier ex Cavalier-Smith, 2002 - blue-green algae |
| class | Cyanophyceae Schaffner, 1909 |
| subclass | Synechococcophycideae |
| order | Synechococcales |
| family | Prochlorococcaceae Komárek & Strunecky |
| genus | Cyanobium Rippka & Cohen-Bazire, 1983 |