Tags: Bacteria.
The SAR11 clade or Pelagibacteraceae defines a lineage of bacteria that is extremely common in the ocean. Bacteria in the SAR11 clade make up roughly one in three cells at the ocean’s surface. Overall SAR11 bacteria are estimated to make up between a quarter and a half of all prokaryotic cells in the ocean.SAR11 bacteria are classified as alphaproteobacteria and include the highly abundant marine species Pelagibacter ubique.