Abstract
During a survey for the presence of Aeromonas salmonicida, 45 Aeromonas isolates which could not be classified in the existing named species of the genus were recovered from water obtained from the River Avon in Hampshire, England. On the basis of a numerical taxonomy study, these isolates were clustered in three homogeneous phena. Phenon 1 was identified as a new species of Aeromonas, for which we propose the name Aeromonas media; strain RM (= ATCC 33907) is the type strain of this species.