Definition
Genus Peridinium refers to a group of dinoflagellates known for having distinct cellulose plates called theca. These plates act like armor. They're single-celled algae found in various aquatic habitats, from oceans to lakes. They have two flagella, allowing a spinning movement. Many are photosynthetic. Some can create harmful algal blooms (HABs). Imagine them as little armored spinning tops.