Dinoflagellates are a group of single-celled organisms found primarily in marine environments. They are known for their unique features, including two flagella that allow them to move through water. Some species can produce light, creating a phenomenon known as bioluminescence, which can be seen in ocean waves at night. These organisms play a crucial role in aquatic ecosystems as primary producers, forming the base of the food web. However, certain dinoflagellate species can also cause harmful algal blooms, leading to issues like red tide, which can affect marine life and human health.