Labeling Fish with an Activable Element Through Their Diet

Abstract

Stable samarium, one of the rare earth elements, was fed to medaka (Oryzias latipes) and goldfish (Carassius auratus). The concentration of samarium in the labeled fish was determined by neutron activation analysis. In O. latipes, samarium was detectable even 1 yr after the labeled diet was eaten. In C. auratus, samarium was retained in the fifth branchial arch, scales, and gills.Key words: fish marking, Oryzias latipes, Carassius auratus, activation analysis, activable tracer, samarium