Light micrograph of Pyrocystis lunula (Gr.pyro, fire & Gr. kystis, bladder) marine dinoflagellate alga cell, showing spindle shaped cells, the right one in binary fission. The chloroplasts with brownish color are extended from the cell centre to the ends of the cell. Pyrocystis in mass reproduction causes a bright bioluminescent ocean glow at night. Culture material of the Culture Collection of Algae at the University of Cologne. Microscopic contrast method: Differential interference contrast. Magnification 180x when printed at 10 centimetres width.