Class Proteobacteria Stackebrandt et al. 1988 see Phylum Proteobacteria Garrity and Holt 2001
   Subclass gamma see Class Gammaproteobacteria nom. inval.
     Family Alteromonadaceae Ivanova and Mikhailov 2001
       Genus Colwellia Deming et al. 1988
         Colwellia psychrotropica Bowman et al. 1998