What are Dinoflagellates?
Dinoflagellates are microscopic, (usually) unicellular, flagellated, often photosynthetic protists, commonly regarded as “algae” (Division Dinoflagellata). They are characterized by a transverse flagellum that encircles the body (often in a groove known as the cingulum) and a longitudinal flagellum oriented perpendicular to the transverse flagellum. This imparts a distinctive spiral to their s …
Dinoflagellates are single-celled organisms that live in oceans, estuaries, lakes, and ponds. Some of them are bioluminescent — they cause a sparkling of the sea at night as the waves break. Some of them cause “red tides,” which can kill fish or poison humans who eat the fish or shellfish that have eaten the dinoflagellates. The Red Sea may have gotten its name from dinoflagellate blooms. Dinoflagellates are most often considered to be plants because many make their own food using air, water, and sunlight. Some dinoflagellates eat other plants or eat small or large animals. Some live within animals such as corals. Many dinoflagellates have a complex life cycle that includes a resting stage. During this stage, the dinoflagellate may live in a very durable capsule called a dinocyst. The dinocyst is studied by paleontologists. Unlike many other fossils, the dinocyst is not a dead dinoflagellate. It is more like a cocoon. There is an opening in the dinocyst through which the dinoflagellat
Dinoflagellates are a group of flagellate unicellular organisms which are considered a type of algae. Their name is from the Greek dinos meaning “whirling” and flagella which means whip. This is a reference to their characteristic whirling motion as they move through the water using two flagella: a longitudinal flagellum and a transverse flagellum. Dinoflagellates make up a major portion of eukaryotic (complex unicellular) oceanic plankton, second in abundance only to the diatoms. Dinoflagellates are known as the source of red tides and one of the sources of oceanic bioluminescence. “Red tides,” also known as harmful algal blooms, occur when phytoplankton (photosynthesizing protists) release harmful chemicals into the water to kill fish and other organisms that threaten to eat them. These chemicals can get into airborne moisture and irritate the lungs and mucus membranes of people on the beach. The phenomenon is most common on the Gulf Coast of Florida. Sometimes red tides are cased by
Living dinoflagellates are one of the most important components in plankton. They are small single-celled organisms, which swim freely in water with a forward spiraling motion propelled by dimorphic flagella: one flagellum oriented around the cell, and the other directed posterior. Cells have plates as a cell covering, and numerous cellular structures: chloroplasts mitochondria and nucleus, which set them apart from other groups of land plants belonging to microscopic algae. Many dinoflagellates are primary producers of food in the aquatic food webs. Dinoflagellates are an integral part of the first link in the aquatic food chain: the initial transfer of light energy to chemical energy (photosynthesis). Almost all other organisms are dependent upon this energy transfer for their subsequent existence. This group of microorganisms comprises a large number of unusual algal species of many shapes and sizes.
The term dinoflagellate means whirling flagella, and refers to the two long, hair-like strands these organisms use for locomotion. Dinoflagellates may be best known for those that cause the summer red tides that can devastate populations of marine life. Fossils of dinoflagellates come in two different forms reflecting their two-stage life cycle: cysts and active stages. The resting-stage cysts are essentially spiny balls, while the active stages are made of many plates in various shapes. Dinoflagellates have been found in rocks as old as the Silurian. First known fossil occurrence: Silurian.Last known fossil occurrence: Quaternary. This group has living relatives.
