Allometry is a matter of metal bioaccumulation in animals.While it is not clear whether the effects are due to body size per se or the physiological traits during the animals development.We therefore investigated the biokinetics of copper (Cu) and predicted Cu bioaccumulation during the development of a fish model, the marine medaka.The results revealed that the waterborne Cu uptake rate constant decreased and dietary Cu assimilation efficiency increased from larvae to adults.The allometric dependency of the biokinetic parameters in juveniles and adults cant be simply extrapolated to the whole life cycle.