Abstract
The nonmotile, vibrioid, curly or ring-forming bacteria were examined to assess their systematic relationships through determination of the guanine-plus-cytosine contents of their deoxyribonucleic acids and the degrees of homology among the deoxyribonucleic acids of the various genera and species. Our results verify that Runella, Flectobacillus, Spirosoma, and Ancylobacter ("Microcyclus") are separate genera. However, our results also indicate that (i) "Ancylobacter eburneus" is not a separate species but is in fact a strain of Ancylobacter aquaticus, (ii) Flectobacillus marinus should not be used to create the new genus "Cyclobacterium" and the latter name should be discarded, and (iii) "Renobacter" is very similar to Ancylobacter, but these two genera exhibit very low levels of deoxyribonucleic acid-deoxyribonucleic acid homology and should probably remain separate at least until additional information is available.