Vibrio related bacteria comprise a significant portion of the heterotrophic bacteria of the world's oceans, costal waters and estuaries. The systematics of these organisms is of major importance in understanding biodiversity at the microbial level. Numerous studies in systematics have been done using traditional traits and, more recently, RNA and DNA data. This study seeks to incorporate phenotypic and genotypic attributes to define more accurately the systematics of the Vibrionaceae, Aeromonadaceae and related organisms. Previous investigations carried out in the laboratory of the PIs focused on collection of morphological and RNA data, as well as developing a number of analyses of this information. This effort will add further RNA and DNA data to the data bank. Our ultimate goal is a complete set of information for reference strains of the genera Vibrio, Aeromonas, Photobacterium, Alteromonas (Shewanella), and others.