Symptoms recalling a nutritional pathology and more precisely a process of lipid peroxydation were observed during the last years in seabass Dicentrarchus labrax and other fishes cultured in tropical marine condition, Ocyurus chrysurus and Lutjanus analis . They included dark coloration, skin ulceration, lethargy, anorexy, emaciation. Histological examinations showed hepatic fatty degenerative lesions, pancreatitis, muscular degeneration and retinal atrophy. Additional vitamins E and C in the food suppressed that pathological symptoms. The previously evoked clinical or histological signs were not achieved in spite of an increase of the level of hepatic, muscular or blood malondialdehyde and of the conjugated dienes of the perivisceral fat. In the same time, hepatic and muscular tocopherol decreased. These experiments also showed the feasibility and the interest of different analyses in the characterization of such a pathology: hemolysis test and activity of enzymes such as erythrocytic catalase or superoxyde dismutase and plasma glutathione peroxydase. Another nutritional disease is worth describing again, the Granulomatous Hypertyrosinaemia. It was essentially investigated in turbot Scophtalmus maximus but other fish species such as sea bream Chrysophris aurata are often affected.