Tenacibaculum piscium sp. nov., isolated from skin ulcers of sea-farmed fish, and description of Tenacibaculum finnmarkense sp. nov. with subdivision into genomovars finnmarkense and ulcerans .

Results of previous multilocus sequence and whole-genome-based analyses have suggested that a homogeneous group of isolates belonging to the genus Tenacibaculum , represented by strain TNO020 ^T and associated with skin ulcer development in sea-farmed fish, represents an as-yet-undescribed species. Comparative whole-genome analysis performed in the present study clustered five isolates, including TNO020 ^T , in a distinct lineage within the genus Tenacibaculum . Phenotypic differences, high intra-cluster average nucleotide identity (ANI) values and low ANI values with other Tenacibaculum species support the proposal of a novel species, for which we propose the name Tenacibaculum piscium sp. nov. with strain TNO020 ^T (=CCUG 73833 ^T =NCIMB 15240 ^T ) as the type strain. Further, large-scale genome analyses confirmed the existence of two different phylogenetic lineages within ' T. finnmarkense ', a species effectively but not validly published previously. ANI values just above the species delineation threshold of 95-96 % confirmed that both lineages belong to the same species. This result was also supported by DNA-DNA hybridization values. Phenotypically, the two conspecific lineages are distinguishable by differences in growth temperature range and ability to degrade l-proline. For the group of isolates already commonly known as ' T. finnmarkense ', we propose the name Tenacibaculum finnmarkense sp. nov., with strain TNO006 ^T (=CCUG 73831 ^T =NCIMB 15238 ^T ) as the type strain. We further propose the subdivision of T. finnmarkense sp. nov. into two genomovars, T. finnmarkense genomovar finnmarkense with strain TNO006 ^T (=CCUG 73831 ^T =NCIMB 15238 ^T ) as the type strain and T. finnmarkense genomovar ulcerans with strain TNO010 ^T (=CCUG 73832 ^T =NCIMB 15239 ^T ) as the type strain.