Hybrid striped bass (M. saxatilis ? x M. chrysops ?) (HSB) and its parental species, white bass (WB), and striped bass (SB) were evaluated for their susceptibility to three detrimental bacterial diseases: Columnaris disease, motile aeromonad septicemia, and streptococcosis. Using mean survival time in days post challenge (± SEM) as the measurable phenotypic trait, we found WB to be the most resistant and SB to be the most susceptible with the hybrid offspring in the middle (n = 225, 5-10g per species). Mean survival in days for three diseases was 5.1 (± 0.48), 4.6 (± 0.68) and 2.5 (± 0.67) for WB, HSB and SB respectively which were significantly different (P ≤ 0.05). The mean percent survival for the three diseases was 66.1 (± 33.1), 34.5 (± 31.9) and 1.1 (± 1.1) for WB, HSB and SB respectively. The culmination of the data generated by these experiments indicate that the striped bass is the most susceptible of the three species and thus the target of selection if improvement of disease resistance phenotype is to be achieved.