Three different ecotypes or potential species have been defined, based on their adaptation to light intensity. One (O. lucimarinus) is adapted to high light intensities and corresponds to surface-isolated strains. The second (RCC141) has been defined as low-light and includes strains from deeper in the water column. The third (O.tauri) corresponds to strains isolated from a coastal lagoon and can be considered light-polyvalent. Comparative analysis of Ostreococcus sp will help to understand niche differentiation in unicellular eukaryotes and evolution of genome size in eukaryotes.
Publication: (2007) The tiny eukaryote Ostreococcus provides genomic insights into the paradox of plankton speciation. Proc Natl Acad Sci U S A., 104, 7705-7710.