AGE-RELATED CELLULAR REACTIONS TO COPPER IN THE MARINE MUSSEL MYTILUS-EDULIS

Marine mussels Mytilus edulis (L.) of different ages were exposed to c opper (50 mug l-1) for up to 6 d and then transferred back to clean se awater. Copper exposure induced lysosomal destabilisation in the diges tive cells of mussels of all ages. However, the mussel's ability to re store lysosomal integrity declined with increasing age. Lipid in the d igestive cells of all mussels was associated with lysosomes after 6 d of copper exposure but its distribution returned to normal in all but the oldest mussels following reimmersion in clean seawater. The lipofu scin content of the digestive glands of all the mussels remained uncha nged during copper exposure but increased in the oldest mussels follow ing reimmersion in seawater. These findings indicate that mussels of a ll ages display a similar susceptibility to stress, but their capacity to recover and hence adapt to environmental changes declines with inc reasing age.