Determination of copper in embryos and very young specimens of Sepia officinalis

The total amount of copper in embryos and newly hatched young individuals of Sepia officinalis L. has been determined by microtechnique, using bathocuproine-sulfonate as complexing reagent. During embryonic life, the total amount of copper does not change; it remains at a level close to 3.8 g. The copper is found in the yolk sac of very early embryos; it is subsequently transferred into the embryo proper. After hatching, the copper content diminishes quickly in starved individuals. Fed S. officinalis also usually lose copper. The reason for this may be that the inner yolk sac of newly hatched individuals contains a great deal of the total copper, which is excreted with the yolk after the latter has become superfluous. Later on, copper must be taken up from the food. The mobilization of protein and copper from the yolk into the blood may account for the early appearance of embryonic hemocyanin in the blood.