EN
This paper describes the first report of gill disease in gilthead sea bream (Sparus aurata L.), cultured in the Northern Adriatic near the island of Cres in Croatia. The pathological findings of cultured gilthead sea bream were examined in detail, using prompt clinical and necropsy examination, bacterial and hematological analysis. Beside yellowish-brown, swollen and clumped gills, there were no other apparent changes in the diseased fish. Bacterial analysis of these fish revealed the presence of mixed infections. The predominant bacterium from affected gills was Stenotrophomonas maltophilia. Furthermore Aeromonas salmonicida masoucida/achromogenes and Empedobacter brevis were also identified. Fish with affected gills had significantly decreased serum proteins, specific weight and haematocrit compared to fish without changes of the gills.