Abstract
During a PCR‐based CEV survey in Poland in 2015–2017, the virus was detected in many farms both in clinical and asymptomatic cases and in common as well as in koi carp ( Cyprinus carpio ). In order to evaluate the potential carrier role of fish species that share the same habitats with carp, an experimental trial was performed. Investigations carried out on specimens of bleak ( Alburnus alburnus ), crucian carp ( Carassius carassius ), European perch ( Perca fluviatilis ), Prussian carp ( Carassius gibelio ), roach ( Rutilus rutilus ) and tench ( Tinca tinca ) cohabited with CEV‐infected carp yielded positive results. These species of fish were experimentally cohabited with CEV‐infected common carp at a temperature of 16°C ± 1. Material from the brain, gills, spleen, kidneys, intestine and skin was investigated for the presence of CEV DNA. Similar investigations were performed with uninfected fish designated controls. Samples were tested for CEV by qPCR.