The aeromonads share many biochemical characteristics with members of the
Enterobacteriaceae, from which they are primarily differentiated by being
oxidase-positive. The genus includes at least 13 genospecies, among which are
the mesophilic A. hydrophila, A. caviae, A. sobria, A. veronii, and A. schubertii,
and the non-motile, psychrophilic A. salmonicida