Figure 1.

The Hawaiian bobtail squid, Euprymna scolopes, and its hemocytes. (A) Adult E. scolopes. Scale, 3 mm. (B) Hemocyte of the host as viewed by DIC imaging. The macrophage-like hemocyte is the only circulating blood cell type found in the host. These cells can infiltrate the crypt spaces of the light organ where they can interact with the symbiont, V. fischeri. Scale, 10 μm. (C) Host hemocyte stained with CellTracker (red) and viewed by confocal microscopy. A sole V. fischeri cell (green; arrow) can be seen bound to the hemocyte. Scale, 10 μm. n, nucleus; c, cytoplasm.