Packaging line for packaging molluscs with an external shell, comprising loading trays (2) for molluscs with an external shell, the loading trays being provided with compartments for receiving a mollusc and being carried by a transfer conveyor (1), and a device (10) for marking molluscs with an external shell, comprising engraving means that are able to engrave an impression onto a shell, and control means that are able to control the engraving of the impression onto the shells of the molluscs located in compartments in a loading tray.