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Gambierdiscus Pacificus
''Gambierdiscus pacificus'' is a species of toxic (ciguatoxin- and maitotoxin-like toxicity) 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 Hypotheca may refer to: * The inner Frustule#Thecae, theca of the frustule (exoskeleton) of a diatom * Hypothec, in civil law, a sort of mortgage {{disambiguation .... References Further reading *Mai Anh, Nguyen Thi. "The morphology and growth characterizations of Gambierdiscus pacificus Chinain et Faust 1999." Journal of Biology 32.3 (2012): 36-43. * External links *AlgaeBase Gonyaulacales Protists described in 1999 Dinoflagellate species {{dinoflagellate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ciguatoxin
image:ciguatoxin.svg, 300px, class=skin-invert-image, Chemical structure of the ciguatoxin CTX1B Ciguatoxins are a class of toxic Polycyclic compound, polycyclic polyethers found in fish that cause ciguatera. There are several different chemicals in this class. "CTX" is often used as an abbreviation. * Ciguatoxin 1 - * Ciguatoxin 2 - * Ciguatoxin 3 - * Ciguatoxin 4B (Gambiertoxin 4b) - Toxic effect on humans Ciguatoxins do not seem to harm the fish that carry them, but they are poisonous to humans. They cannot be smelled or tasted and cannot be destroyed by cooking. Rapid testing for this toxin in food is not standard. Some ciguatoxins lower the threshold for opening excitatory voltage-gated sodium channels in the nervous system. Opening a sodium channel causes depolarization, which could sequentially cause paralysis, heart arrhythmia, and changing the senses of heat and cold. Such poisoning from ciguatoxins is known as ciguatera. Ciguatoxins are lipophilic, able to cros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maitotoxin
Maitotoxin (MTX) is an extremely potent toxin produced by ''Gambierdiscus toxicus'', a dinoflagellate species. Maitotoxin has been shown to be more than one hundred thousand times as potent as VX nerve agent. Maitotoxin is so potent that it has been demonstrated that an intraperitoneal injection of 130 ng/kg was lethal in mice. Maitotoxin was named from the ciguateric fish '' Ctenochaetus striatus''—called "maito" in Tahiti—from which maitotoxin was isolated for the first time. It was later shown that maitotoxin is actually produced by the dinoflagellate ''Gambierdiscus toxicus''. Mechanism of toxicity Maitotoxin activates extracellular calcium channels, leading to an increase in levels of cytosolic Ca2+ ions. The exact molecular target of maitotoxin is unknown, but it has been suggested that maitotoxin binds to the plasma membrane Ca2+ ATPase (PMCA) and turns it into an ion channel, similar to how palytoxin turns the Na+/K+-ATPase into an ion channel. Ultimate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinoflagellate
The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also 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 ( phagotrophy and myzocytosis). In terms of number of species, dinoflagellates are one of the largest groups of marine eukaryotes, although substantially smaller than diatoms. Some species are endosymbionts of marine animals and play an important part in the biology of coral reefs. Other dinoflagellates are unpigmented predators on other protozoa, and a few forms are parasitic (for example, '' Oodinium'' and '' Pfiesteria''). Some dinoflagellates produce resting stages, called dinoflagellate cys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI Unit, SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cell (biology), cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frustule
A frustule is the hard and porous cell wall or external layer of diatoms. The frustule is composed almost purely of silica, made from silicic acid, and is coated with a layer of organic substance, which was referred to in the early literature on diatoms as pectin, a fiber most commonly found in cell walls of plants. This layer is actually composed of several types of polysaccharides.Progress in Phycological Research: v. 7 (1991) by F.E. Round (Volume editor), David J. Chapman (Volume editor) The frustule's structure is usually composed of two overlapping sections known as thecae (or less formally as valves). The joint between the two thecae is supported by bands of silica (girdle bands) that hold them together. This overlapping allows for some internal expansion room and is essential during the reproduction process. The frustule also contains many pores called areolae and slits that provide the diatom access to the external environment for processes such as waste removal and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gonyaulacales
Gonyaulacales is an order of dinoflagellate The Dinoflagellates (), also called Dinophytes, are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered protists. Dinoflagellates are mostly marine plankton, but they are also commo ...s found in marine environments. References Dinoflagellate orders {{dinoflagellate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protists Described In 1999
A protist ( ) or protoctist is any eukaryotic organism that is not an animal, land plant, or fungus. Protists do not form a natural group, or clade, but are a paraphyletic grouping of all descendants of the last eukaryotic common ancestor excluding land plants, animals, and fungi. Protists were historically regarded as a separate taxonomic kingdom known as Protista or Protoctista. With the advent of phylogenetic analysis and electron microscopy studies, the use of Protista as a formal taxon was gradually abandoned. In modern classifications, protists are spread across several eukaryotic clades called supergroups, such as Archaeplastida (photoautotrophs that includes land plants), SAR, Obazoa (which includes fungi and animals), Amoebozoa and "Excavata". Protists represent an extremely large genetic and ecological diversity in all environments, including extreme habitats. Their diversity, larger than for all other eukaryotes, has only been discovered in recent decades thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
