Dinoflagellate

Dinoflagellate

Dinophyceae
Noctiluciphyceae
Syndiniophyceae

The dinoflagellates (Greek δῖνος dinos "whirling" and Latin flagellum "whip, scourge") are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats, as well. Their populations are distributed depending on temperature, salinity, or depth. Many dinoflagellates are known to be photosynthetic, but a large fraction of these are in fact mixotrophic, combining photosynthesis with ingestion of prey. Dinoflagellates are the largest group of marine eukaryotes aside from the diatoms. Being primary producers makes them an important part of the aquatic food chain. Some species, called zooxanthellae, are endosymbionts of marine animals and play an important part in the biology of coral reefs. Other dinoflagellates are colorless predators on other protozoa, and a few forms are parasitic (see for example Oodinium, Pfiesteria). Some dinoflagellates produce resting stages, called dinoflagellate cysts or dinocysts, as part of their life cycles.

Dinoflagellates are considered to be protists, with their own division, Dinoflagellata.

About 1,555 species of free-living marine dinoflagellates are currently described. Another estimate suggests ca. 2000 living species, of which more than 1700 are marine and about 220 are from freshwater. The latest estimates suggest a total of 2,294 living dinoflagellate species, which includes marine, freshwater and parasitic dinoflagellates.

An algal bloom of dinoflagellates can result in a visible coloration of the water colloquially known as red tide.

Many reviews have been written on dinoflagellates.