Whole-genome sequencing reveals that Shewanella haliotis Kim et al. 2007 can be considered a later heterotypic synonym of Shewanella algae Simidu et al. 1990

Previously, experimental DNA-DNA hybridization (DDH) between Shewanella haliotis JCM 14758(T) and Shewanella algae JCM 21037(T) had suggested that the two strains could be considered different species, despite minimal phenotypic differences. The recent isolation of Shewanella sp. MN-01, with 99% 16S rRNA gene identity to S. algae and S. haliotis, revealed a potential taxonomic problem between these two species. In this study, we reassessed the nomenclature of S. haliotis and S. algae using available whole-genome sequences. The whole-genome sequence of S. haliotis JCM 14758(T) and ten S. algae strains showed >= 97.7% average nucleotide identity and >78.9% digital DDH, clearly above the recommended species thresholds. According to the rules of priority and in view of the results obtained, S. haliotis is to be considered a later heterotypic synonym of S. algae. Because the whole-genome sequence of Shewanella sp. strain MN-01 shares >99% ANI with S. algae JCM 14758(T), it can be confidently identified as S. algae.