We describe the polyphasic characterization of four Vibrio isolates which formed a tight AFLP group in a former study. The group was closely related to V. cyclitrophicus, V. lentus and V. splendidus (98.2-98.9% similarity) on the basis of the 16S rDNA sequence analysis, but by DNA-DNA hybridisation experiments it had at maximum 61% DNA similarity towards V. splendidus. Thus, we propose that the isolates represent a new Vibrio species i.e. V. tasmaniensis (LMG 20012T; EMBL under the accession numbers AJ316192; mol% G+C of DNA of the type strain is 44.7). Useful phenotypical features for discrimination of V. tasmaniensis from other Vibrio species include gelatinase and beta-galactosidase activity, fatty acid composition (particularly 14:0), utilisation and fermentation of different compounds (e.g. sucrose, melibiose and D-galactose) as sole carbon source.