Differential interference contrast (DIC) light micrograph of Pyrocystis lunula algae. Pyrocystis lunula is a crescent-shaped bioluminescent microalga. When disturbed, it creates bioluminescence due to a chemical reaction with the enzyme luciferase. Pyrocystis is a dinoflagellate, an aquatic organism that has characteristics of both plants and animals. Magnification: x260 when printed at 10 centimetres wide.