Susceptibility of Common Carp to the New Ulcer Disease-Causing Atypical Aeromonas salmonicida is Temperature-Dependent, but Not Body Size-Dependent

In this study, we investigated the influence of body-size and temperature on the susceptibility of carp Cyprinus carpio to the new ulcer disease caused by atypical Aeromonas salmonicida. ​We observed that 4–7 cm long carp, weighing 1.6–8.6 g, exhibited similar susceptibility to the disease. ​Furthermore, A. salmonicida cultured at 25°C demonstrated significantly reduced virulence compared to the bacterium cultured at 20°C. ​Additionally, a higher disease occurrence rate was noted at a water temperature of 25°C during infection, with faster symptom recovery.