On the Uptake of 65Zn and the Concentration Factor on Zn in Marine Organisms I. Uptake of 65Zn in Marine Organisms

Abstract

In order to know the concentration factor of Zn in marine organisms, shellfish, echinoderm and fish were kept in sea water containing ⁶⁵Zn and the uptake of radioactivity by organisms was traced. Two series of experiments were carried out. In the experiment A, the distribution of the nuclide and concentration factor in each organ and tissue were observed. In the experiment B, the influence of Zn content in sea water on the uptake of radioactive Zn was checked by means of the whole body counting. Zn determination was made on the muscle of T. japonica to obtain the concentration factor which was compared with that obtained by tracer experiment. The concentration factors of Zn are different in different organisms as well as in different tissues and the following figures were obtained; 3-20 for fish, 50-400 for shellfish and 15-500 for sea urchin. However, as the equilibrium was not reached in many of organs and tissues within 42 days of experimental period, higher values should be considered as the concentration factor at the equilibrium condition. The concentration factor for the muscle of T. japonica was observed to be 5, 600 by chemical analysis and 50 by tracer experiment. The cause of this big discrepancy is yet unknown but may be partly due to the fact that Zn content of sea water changed greatly during the rearing experiment.