Light micrograph of Pyrocystis noctiluca(Gr.pyro, fire & Gr. kystis, bladder) marine dinoflagellate alga cells, showing bladder shaped cells with chloroplasts in daylight position, where 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: Darkfield contrast. Magnification 100x when printed at 10 centimetres width.