After several minutes of observation chloroplasts are transported to the cell center, maybe to save the nucleus and most of the chloroplasts against harmful amounts of UV radiation. The image was built up using several photomicrographic frames with manual stacking technique. Scale bar indicates 50 µm.
Sample from North Sea near Heligoland (spring diatom bloom). Images were taken using Zeiss Universal with Olympus C7070 CCD camera.