Differential involvement of mussel hemocyte sub-populations in the clearance of bacteria.

Abstract Mussels are filter-feeders living in a bacteria-rich environment. We have previously found that numerous bacterial species are naturally present within the cell-free hemolymph, including several of the Vibrio genus, whereas the intra-cellular content of hemocytes was sterile. When bacteria were injected into the circulation of the mussel, the number of living intra-hemocyte bacteria dramatically increased in less than an hour, suggesting intense phagocytosis, then gradually decreased, with no viable bacteria remaining 12 h post-injection for Micrococcus lysodeikticus, 24 h for Vibrio splendidus and more than 48 h for V ibrio anguillarum. The total hemocyte count (THC) was dramatica…