CYTOBIOLOGICAL STUDIES ON HEMOCYANIN METABOLISM IN THE BRANCHIAL HEART COMPLEX OF THE COMMON CUTTLEFISH SEPIA-OFFICINALIS (CEPHALOPODA, DIBRANCHIATA)

The present study confirms previous investigations that demonstrated a high copper content in the branchial heart and its appendage, and tha t gave the first indication that this organ complex might be involved in hemocyanin metabolism in Sepia officinalis L. Immunocytochemical lo calization of hemocyanin molecules within the endocytotic lysosomal sy stem of the ovoid cells and tracer experiments with I-125-labeled Sepi a hemocyanin suggest its endocytotic uptake. Energy-dispersive X-ray m icroanalysis and histochemical methods reveal a high copper content wi thin the ovoid cells of the branchial heart. In view of the turnover o f the respiratory pigment in the branchial heart of Sepia officinalis L., we believe that the ovoid cells are a site of hemocyanin catabolis m.