The dinoflagellates are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they also are common in freshwater habitats. Their populations vary with sea surface temperature, salinity, and depth. Many dinoflagellates are photosynthetic, but a large fraction of these are in fact mixotrophic, combining photosynthesis with ingestion of prey.
Karenia brevis is a microscopic, single-celled, photosynthetic organism in the genus Karenia. It is a marine dinoflagellate commonly found in the waters of the Gulf of Mexico. It is the organism responsible for the "Florida red tides" that affect the Gulf coasts of Florida and Texas in the U.S., and nearby coasts of Mexico. K. brevis has been known to travel great lengths around the Florida peninsula and as far north as the Carolinas.
Predatory dinoflagellates are predatory heterotrophic or mixotrophic alveolates that derive some or most of their nutrients from digesting other organisms. About one half of dinoflagellates lack photosynthetic pigments and specialize in consuming other eukaryotic cells, and even photosynthetic forms are often predatory.
Alexandrium fundyense is a species of dinoflagellates. It produces toxins that induce paralytic shellfish poisoning (PSP), and is a common cause of red tide. A. fundyense regularly forms massive blooms along the northeastern coasts of the United States and Canada, resulting in enormous economic losses and public health concerns.
Gambierdiscus toxicus is a species of photosynthetic unicellular eukaryote belonging to the Alveolata, part of the SAR supergroup. It is a dinoflagellate which can cause the foodborne illness ciguatera, and is known to produce several natural polyethers including ciguatoxin, maitotoxin, gambieric acid, and gambierol. The species was discovered attached to the surface of brown macroalgae.
Karenia is a genus that consists of unicellular, photosynthetic, planktonic organisms found in marine environments. The genus currently consists of 12 described species. They are best known for their dense toxic algal blooms and red tides that cause considerable ecological and economical damage; some Karenia species cause severe animal mortality. One species, Karenia brevis, is known to cause respiratory distress and neurotoxic shellfish poisoning (NSP) in humans.
The Gymnodiniales are an order of dinoflagellates, of the class Dinophyceae. Members of the order are known as gymnodinioid or gymnodinoid. They are athecate, or lacking an armored exterior, and as a result are relatively difficult to study because specimens are easily damaged. Many species are part of the marine plankton and are of interest primarily due to being found in algal blooms. As a group the gymnodinioids have been described as "likely one of the least known groups of the open ocean phytoplankton."
Karlodinium is a genus of athecate dinoflagellates that lives worldwide. They are often toxin producing, and compared to the other members of the Kareniaceae, are fairly small at <8-15 µm diameter. They are also able to form intense algal blooms. This species relies of photosynthesis and phagotrphy to grow.
Dinophysis is a genus of dinoflagellates common in tropical, temperate, coastal and oceanic waters. It was first described in 1839 by Christian Gottfried Ehrenberg.
Gonyaulax is a genus of dinoflagellates with the type species Gonyaulax spinifera Diesing. Gonyaulax belongs to red dinoflagellates and commonly causes red tides. It secretes a poisonous toxin known as "saxitoxin" which causes paralysis in humans.
Alexandrium is a genus of dinoflagellates. It contains some of the dinoflagellate species most harmful to humans, because it produces toxic harmful algal blooms (HAB) that cause paralytic shellfish poisoning (PSP) in humans. There are about 30 species of Alexandrium that form a clade, defined primarily on morphological characters in their thecal plates.
Cochlodinium polykrikoides is a species of red tide producing marine dinoflagellates known for causing fish kills around the world, and well known for fish kills in marine waters of Southeast Asia. C. polykrikoides has a wide geographic range, including North America, Central America, Western India, Southwestern Europe and Eastern Asia. Single cells of this species are ovoidal in shape, 30-50μm in length and 25-30μm in width.
Gambierdiscus pacificus is a species of toxic dinoflagellate. It is 67–77 μm long and 60–76 μm wide dorsoventrally and its surface is smooth. It is identified by a four-sided apical pore plate surrounded by 30 round pores. Its first plate occupies 20% of the width of the hypotheca.
Karenia bicuneiformis, also known as Karenia bidigitata is a microbial species from the genus Karenia, which are dinoflagellates. It was first discovered in New Zealand.
Gambierdiscus is a genus of marine dinoflagellates that produce ciguatoxins, a type of toxin that causes the foodborne illness known as ciguatera. They are usually epiphytic on macroalgae growing on coral reefs.
Polykrikos is one of the genera of family Polykrikaceae that includes athecate pseudocolony-forming dinoflagellates. Polykrikos are characterized by a sophisticated ballistic apparatus, named the nematocyst-taeniocyst complex, which allows species to prey on a variety of organisms. Polykrikos have been found to regulate algal blooms as they feed on toxic dinoflagellates. However, there is also some data available on Polykrikos being toxic to fish.
Coolia is a marine dinoflagellate genus in the family Ostreopsidaceae. It was first described by Meunier in 1919. There are currently seven identified species distributed globally in tropical and temperate coastal waters. Coolia is a benthic or epiphytic type dinoflagellate: it can be found adhered to sediment or other organisms but it is not limited to these substrates. It can also be found in a freely motile form in the water column. The life cycle of Coolia involves an asexual stage where the cell divides by binary fission and a sexual stage where cysts are produced. Some of the species, for example, Coolia tropicalis and Coolia malayensis, produce toxins that can potentially cause shellfish poisoning in humans.
Lepidodinium is a genus of dinoflagellates belonging to the family Gymnodiniaceae. Lepidodinium is a genus of green dinoflagellates in the family Gymnodiniales. It contains two different species, Lepidodiniumchlorophorum and Lepidodinium viride. They are characterised by their green colour caused by a plastid derived from Pedinophyceae, a green algae group. This plastid has retained chlorophyll a and b, which is significant because it differs from the chlorophyll a and c usually observed in dinoflagellate peridinin plastids. They are the only known dinoflagellate genus to possess plastids derived from green algae. Lepidodinium chlorophorum is known to cause sea blooms, partially off the coast of France, which has dramatic ecological and economic consequences. Lepidodinium produces some of the highest volumes of Transparent Exopolymer Particles of any phytoplankton, which can contribute to bivalve death and the creation of anoxic conditions in blooms, as well as playing an important role in carbon cycling in the ocean.
Kareniaceae is a accepted marine family of relatively small, toxic, unarmored dinoflagellates belonging to the order Gymnodiniales. Species in the Kareniaceae clade often times cause discolored green Harmful algea blooms (HABs) that pose a safety and health risk to humans and the regions around it. Such blooms also pose a risk to coastal aquaculture worldwide, especially places like France, Atlantic ocean, the English channel and the Mediterranean sea.
Warnowia is a genus of athecate dinoflagellates, characterized by having a very sophisticated photoreceptor organelle called the ocelloid. This genus is dispersed worldwide but is scarce and difficult to find and nearly impossible to culture. As a result, the history and taxonomy of this genus are confusing at best, and many basic characteristics like its life cycle are still unknown. Still, Warnowia has drawn scientific interest as a unicellular organism with a fascinatingly complex photoreceptor system.
