The collapse of the spring bloom is often followed by a clear water phase. When, after a few calm and beautiful days, the sea shines at night it is almost certain that the sea sparkle Noctiluca scintillans (Dinophyta) is inhabiting our waters. This very large (½ mm in diameter) and transparent gelatinous dinoflagellate emits a sparkle of light when touched to frighten its enemies. This phytoplankton species cannot, due to lack of chlorophyll, use sunlight as an energy source and therefore needs to ingest food particles from the water column to gain its carbon. The image shows Noctiluca scintillans with two filled food vacuoles.