Definition
A dinoflagellate is a single-celled eukaryotic organism, often a type of algae. They have two flagella for movement, one wrapped around a groove in the middle, making them spin. Many are photosynthetic, but some eat other organisms. They're known for causing red tides, which can be harmful. Think of them as tiny, spinning, and sometimes toxic, underwater dancers. They differ from diatoms, which have silica shells.