What is Dinoflagellates ?

Dinoflagellata or dinoflagellates, are characteristically unicellular photosynthetic organisms that usually have two flagellae. One flagellum typically surrounds the cell like a belt and undulates in a groove called a girdle, and the other flagellum usually trails. The direction of movement is perpendicular to the girdle.

Dinoflagellates are aquatic, and most of the species live in marine habitats. A large number of species are "armored." That is, they have cellulose plates that combine with silica to produce a tough shell around themselves.

Dinoflagellates have various modes of nutrition - most have chlorophyll a and c, and are photosynthetic, some are colorless, and some are able to eat other organisms. Several species of dinoflagellates live symbiotically within other organisms, most notably jellyfish, corals and mollusks, and are referred to as zoozanthellae.

Dinoflagellates are also notorious for causing red tides. Red tides are named after the red color that is produced by large numbers of dinoflagellate cells in the water column. These massive plankton "blooms" result from huge population explosions that occur from time to time. The dinoflagellates that reproduce in large numbers contain a powerful toxin that builds up in the filter feeders that eat the plankton. The filter feeders such as clams, mussels, and oysters are not affected by the toxin buildup, but when fish, birds and sea mammals eat them, death results. Even humans are susceptible to the respiratory failure caused by the toxin.