Gas bubble disease in Nile Tilapia and Hybrid Red Tilapia (Cichlidae, Oreochromis spp.) under culture conditions

The supersaturated gases in water can cause gas bubble disease in fish and this can result in death. At the present study a case of gas bubble disease resulted from the gas supersaturation were investigated in Nile tilapia (Oreochromis niloticus) and hybrid red tilapia (Oreochromis sp.). Macroscopic and histological findings were obtained from the culture conditions to find more knowledge on this disease which is frequently seen in fish farming. Study was conducted as two steps in summer (August) and winter (December) months with experimentally cultured fish. According to clinical and histological examinations gas bubbles were found in the dorsal, pectoral and caudal fin, and petechial bleeding were found on pectoral, dorsal, caudal fins and the gill cover. The necropsy were revealed that the stomach and intestines were filled with gas bubbles and the gills were hemorrhagic. According to the histological findings hyperplasia and edema in the gills and hemorrhage in the liver and spleen were found, and gastrointestinal mucosa destruction was observed. The clinical findings were similar for both fishes except for a few special cases and it was observed that the effects of supersaturation were severe for both fish species