A toxin is a naturally occurring poison produced by metabolic activities of living cells or organisms. They occur especially as proteins, often conjugated. The term was first used by organic chemist Ludwig Brieger (1849–1919) and is derived from the word "toxic".
Saxitoxin (STX) is a potent neurotoxin and the best-known paralytic shellfish toxin. Ingestion of saxitoxin by humans, usually by consumption of shellfish contaminated by toxic algal blooms, is responsible for the illness known as paralytic shellfish poisoning (PSP).
Palytoxin, PTX or PLTX is an intense vasoconstrictor, and is considered to be one of the most poisonous non-protein substances known, second only to maitotoxin in terms of toxicity in mice.
Okadaic acid, C44H68O13, is a toxin produced by several species of dinoflagellates, and is known to accumulate in both marine sponges and shellfish. One of the primary causes of diarrhetic shellfish poisoning, okadaic acid is a potent inhibitor of specific protein phosphatases and is known to have a variety of negative effects on cells. A polyketide, polyether derivative of a C38 fatty acid, okadaic acid and other members of its family have shined light upon many biological processes both with respect to dinoflagellete polyketide synthesis as well as the role of protein phosphatases in cell growth.
Paralytic shellfish poisoning (PSP) is one of the four recognized syndromes of shellfish poisoning, which share some common features and are primarily associated with bivalve mollusks. These shellfish are filter feeders and accumulate neurotoxins, chiefly saxitoxin, produced by microscopic algae, such as dinoflagellates, diatoms, and cyanobacteria. Dinoflagellates of the genus Alexandrium are the most numerous and widespread saxitoxin producers and are responsible for PSP blooms in subarctic, temperate, and tropical locations. The majority of toxic blooms have been caused by the morphospecies Alexandrium catenella, Alexandrium tamarense, Gonyaulax catenella and Alexandrium fundyense, which together comprise the A. tamarense species complex. In Asia, PSP is mostly associated with the occurrence of the species Pyrodinium bahamense.
Amnesic shellfish poisoning (ASP) is an illness caused by consumption of shellfish that contain the marine biotoxin called domoic acid. In mammals, including humans, domoic acid acts as a neurotoxin, causing permanent short-term memory loss, brain damage, and death in severe cases.
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.
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 can produce yesotoxins: for example, strains of Gonyaulax spinifera from New Zealand are yessotoxin producers.
Yessotoxins are a group of lipophilic, sulfur bearing polyether toxins that are related to ciguatoxins. They are produced by a variety of dinoflagellates, most notably Lingulodinium polyedrum and Gonyaulax spinifera.
Azaspiracids (AZA) are a group of polycyclic ether marine algal toxins produced by the small dinoflagellate Azadinium spinosum that can accumulate in shellfish and thereby cause illness in humans.
Coolia tropicalis is a species of dinoflagellates, first found in Belize.
Canadian Reference Materials (CRM) are certified reference materials of high-quality and reliability produced by the National Metrology Institute of Canada – the National Research Council Canada. The NRC Certified Reference Materials program is operated by the Measurement Science and Standards portfolio and provides CRMs for environmental, biotoxin, food, nutritional supplement, and stable isotope analysis. The program was established in 1976 to produce CRMs for inorganic and organic marine environmental analysis and remains internationally recognized producer of CRMs.
Dinophysis acuminata is a marine plankton species of dinoflagellates that is found in coastal waters of the north Atlantic and Pacific oceans. The genus Dinophysis includes both phototrophic and heterotrophic species. D. acuminata is one of several phototrophic species of Dinophysis classed as toxic, as they produce okadaic acid which can cause diarrhetic shellfish poisoning (DSP). Okadiac acid is taken up by shellfish and has been found in the soft tissue of mussels and the liver of flounder species. When contaminated animals are consumed, they cause severe diarrhoea. D. acuminata blooms are constant threat to and indication of diarrhoeatic shellfish poisoning outbreaks.
Karenia selliformis is a species from the genus Karenia, which are dinoflagellates. It was first discovered in New Zealand. Karenia selliformis produces the highly toxic gymnodimine, and as such is a potentially harmful ocean dweller. Gymnodimine is a nicotinic acetylcholine receptor-blocking phycotoxin, a source of shellfish poisoning.
Antillatoxin (ATX) is a potent lipopeptide neurotoxin produced by the marine cyanobacterium Lyngbya majuscula. ATX activates voltage-gated sodium channels, which can cause cell depolarisation, NMDA-receptor overactivity, excess calcium influx and neuronal necrosis.
Gonyautoxins (GTX) are a few similar toxic molecules that are naturally produced by algae. They are part of the group of saxitoxins, a large group of neurotoxins along with a molecule that is also referred to as saxitoxin (STX), neosaxitoxin (NSTX) and decarbamoylsaxitoxin (dcSTX). Currently eight molecules are assigned to the group of gonyautoxins, known as gonyautoxin 1 (GTX-1) to gonyautoxin 8 (GTX-8). Ingestion of gonyautoxins through consumption of mollusks contaminated by toxic algae can cause a human illness called paralytic shellfish poisoning (PSP).
Pinnatoxins are paralytic chemical compounds that inhibit neuronal and muscle-type nicotinic acetylcholine receptors. Although first discovered in shellfish, they are produced by the peridinoid dinoflagellate Vulcanodinium rugosum. Eight subtypes, designated pinnatoxin A-H, have been described.
Decarbamoylsaxitoxin, abbreviated as dcSTX, is a neurotoxin which is naturally produced in dinoflagellate. DcSTX is one of the many analogues of saxitoxin (STX).
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.
