Natura - nature
   actualia - actual entities
     Mundus Plinius - physical world
       naturalia - natural bodies
         Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
           Domain Bacteria Woese et al. 2024
             Kingdom Pseudomonadati (Gibbons and Murray 1978) Oren and Göker 2024
               Phylum Pseudomonadotaᵀ Garrity et al. 2021
                 Class Betaproteobacteria Garrity et al. 2006
                   Order Neisseriales Tønjum 2006
                     Family Aquaspirillaceae Chen et al. 2022
                       Genus Aquaspirillumᵀ Hylemon et al. 1973 (Approved Lists 1980)
                         01 ?Aquaspirillum dispar Hylemon et al. 1973 (Approved Lists 1980)
                         02 Aquaspirillum arcticum Butler et al. 1990
                         03 Aquaspirillum polymorphum (Williams and Rittenberg 1957) Hylemon et al. 1973 (Approved Lists 1980)
                         04 Aquaspirillum putridiconchylium (Terasaki 1961) Hylemon et al. 1973 (Approved Lists 1980)
                         05 Aquaspirillum serpens (Müller 1786) Hylemon et al. 1973 (Approved Lists 1980)