ELEMENTAL DISTRIBUTION IN ORGANS OF MEDAKA, Oryzias laptipes, BURDENED WITH X-RAY IRRADIATION AND SALTY WATER

Balance of essential elements in organisms is possibly changed by environmental stresses. Small toleost fish, Medaka, was burdened with X-ray irradiation (total dose: 17Gy) and salty water (70% NaCl of sea water). These stresses are not lethal dose. Essential elements in various organs in the fish were. measured by PIXE method and compared with a control fish to determine the effect of two types of the burdens in the elemental contents. Fe, Cu, Zn and Mn are examined in brain, eye, liver, ovary, spleen and intestine. In the liver and spleen, the contents of these elements in stressed fishes are higher than in the control fish. The change of the contents of the elements in brain was small in both cases of X-ray and salty water. It is provided that the balance shift of essential elements occurred in Medaka with the stresses can be observed using PIXE method.