SOME ANATOMIC AND MORPHOLOGIC CHARACTERISTICS OF CULTURED AND WILD TUNA
2008, 66 (2) p. 55-67
The main task of this paper is to describe digestive tract of bluefin tuna, with special focus on the liver. The samples for the research on tuna digestive tract where taken on the tuna farm »Sardina« d.d. Postira. The investigation were done on 22 samples (necropsy and photography of organs, Canon digital camera), 30 samples liver of unfatted tuna, 30 samples liver of fatted tuna and 20 histologic samples of liver before and after fattening. The quality of nutrition directly affects the differences of longitudinal and latitudinal values of the hepatosomatic index and the histology of liver of fatted and unfitted fish. Intensive, lipid–rich nutrition increases the quantity of the fat stored in liver therefore causing higher hepatosomatic index in fatted tuna. Histologic examination of fatted tuna indicates a beginning of hepatocytes degeneration with vacuolization of the cell and decentralized nuclei. Lack of eosinophilic granules in cytoplasm of hepatocytes indicates the cell’s inability of doing enzymatic activity, respectively its dysfunction.