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Polykrikos Kofoidii
''Polykrikos kofoidii'' is a species of phagotrophic marine pseudocolonial dinoflagellates that can capture and engulf other protist prey, including the toxic dinoflagellate, ''Alexandrium tamarense''. ''P. kofoidii'' is of scientific interest due to its status as a predator of other dinoflagellates, a behavior that is significant in the control of algal blooms. It has a complex life cycle of both vegetative (asexual) and sexual reproduction complicated by its pseudocolonial structure. References Species described in 1914 Gymnodiniales {{dinoflagellate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Microscopy
Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of microscopy: optical microscope, optical, electron microscope, electron, and scanning probe microscopy, along with the emerging field of X-ray microscopy. Optical microscopy and electron microscopy involve the diffraction, reflection (physics), reflection, or refraction of electromagnetic radiation/electron beams interacting with the Laboratory specimen, specimen, and the collection of the scattered radiation or another signal in order to create an image. This process may be carried out by wide-field irradiation of the sample (for example standard light microscopy and transmission electron microscope, transmission electron microscopy) or by scanning a fine beam over the sample (for example confocal laser scanning microscopy and scanning electro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polykrikos
''Polykrikos'' (from Greek “poly” - many, and “krikos” – ring or circle) 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. History of knowledge ''Polykrikos'' was first seen in 1868 by Uljanin and was mistakenly considered as a metazoan larva of a turbellarian flatworms. In 1873 Butschili re-examined the specimen and concluded that the cell was an unusual ciliate, and Bergh later, in 1881, clarified ''Polykrikos'' dinoflagellate affinities. Morphology ''Polykrikos'' is a colony of zooids (units of a colonial organism) that carry out simultaneous functions of a whole cell. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algal Bloom
An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in freshwater or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria. ''Algal bloom'' commonly refers to the rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest. Algal blooms are the result of a nutrient, like nitrogen or phosphorus from various sources (for example fertilizer runoff or other forms of nutrient pollution), entering the aquatic system and causing excessive growth of algae. An algal bloom affects the whole ecosystem. Consequences range from the benign feeding of higher trophic levels to more harmful effects like blocking sunlight from reaching other organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predator
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation, sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell. Many predatory animals, both vertebrate and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alexandrium Tamarense
''Alexandrium tamarense'' is a species of dinoflagellates known to produce saxitoxin, a neurotoxin which causes the human illness clinically known as paralytic shellfish poisoning (PSP). Multiple species of phytoplankton are known to produce saxitoxin, including at least 10 other species from the genus ''Alexandrium''. Recent molecular work shows that this species belongs to the ''Alexandrium tamarense'' complex (Atama complex, including ''A. tamarense,'' ''Alexandrium fundyense ''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 th ...,'' '' Alexandrium catenella'') and that none of the three original morphospecies designations forms monophyletic groups in the present SSU-based and previous LSU-based phylogenetic trees, i.e. these species designations are invalid. There is docosahexaenoic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protist
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exclusion of other eukaryotes means that protists do not form a natural group, or clade. Therefore, some protists may be more closely related to animals, plants, or fungi than they are to other protists. However, like the groups ''algae'', ''invertebrates'', and '' protozoans'', the biological category ''protist'' is used for convenience. Others classify any unicellular eukaryotic microorganism as a protist. The study of protists is termed protistology. History The classification of a third kingdom separate from animals and plants was first proposed by John Hogg in 1860 as the kingdom Protoctista; in 1866 Ernst Haeckel also proposed a third kingdom Protista as "the kingdom of primitive forms". Originally these also included prokaryotes, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phagotrophic
Phagocytosis () is the process by which a cell uses its plasma membrane to engulf a large particle (≥ 0.5 μm), giving rise to an internal compartment called the phagosome. It is one type of endocytosis. A cell that performs phagocytosis is called a phagocyte. In a multicellular organism's immune system, phagocytosis is a major mechanism used to remove pathogens and cell debris. The ingested material is then digested in the phagosome. Bacteria, dead tissue cells, and small mineral particles are all examples of objects that may be phagocytized. Some protozoa use phagocytosis as means to obtain nutrients. History Phagocytosis was first noted by Canadian physician William Osler (1876), and later studied and named by Élie Metchnikoff (1880, 1883). In immune system Phagocytosis is one main mechanisms of the innate immune defense. It is one of the first processes responding to infection, and is also one of the initiating branches of an adaptive immune response. Although mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Édouard Chatton
Édouard Chatton (; 11 October 1883 – 23 April 1947) was a French biologist who first characterized the distinction between the prokaryotic and eukaryotic cellular types. Chatton coined the terms and published them first in his 1937 paper ''"Pansporella perplex: Reflections on the Biology and Phylogeny of the Protozoa."'' Chatton was born in Romont, Switzerland. His initial interest was in various human pathogenic protozoa, members of the Apicomplexa and Trypanosomatids. He later expanded his studies to include marine protists, helping to contribute to the description of the dinoflagellate protists. At the Pasteur Institute he met and became a mentor to André Michel Lwoff, future Nobel Laureate in Physiology or Medicine. The two scientists remained associates until Chatton's death in 1947, in Banyuls-sur-Mer Banyuls-sur-Mer (; ) is a commune in the Pyrénées-Orientales department in southern France. It was first settled by Greeks starting in 400 BCE. Geography Lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polykrikaceae
The Polykrikaceae (also known as Polykrikidae) are a family of athecate dinoflagellates of the order Gymnodiniales. Members of the family are known as polykrikoids. The family contains two genera: '' Polykrikos'' and '' Pheopolykrikos''. Characteristics The most distinctive feature of polykrikoids is their formation of multinucleate "pseudocolonies" consisting of an even number of subunit zooids. The two genera differ in number of nuclei; possessing two nuclei regardless of the number of zooids is a synapomorphy for ''Polykrikos'', whereas ''Pheopolykrikos'' possess equal numbers of nuclei and zooids. Along with the Warnowiaceae (warnowiids), polykrikoids are known for possessing unusually complex subcellular structures. In particular, an extrusome complex of two organelles called the nematocyst and taeniocyst is considered a synapomorphy for ''Polykrikos''. Molecular phylogenetics studies suggest some inconsistency in the taxonomy of this group, particularly in the assig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nematocyst (dinoflagellate)
A nematocyst is a subcellular structure or organelle containing extrusive filaments found in two families of theca, athecate dinoflagellates (a group of unicellular eukaryotes), the Warnowiaceae and Polykrikaceae. It is distinct from the similar subcellular structures found in the cnidocyte cells of cnidarians, a group of multicellular organisms including jellyfish and corals; such structures are also often called nematocysts (alternatively, ''cnidocysts'' or ''cnidae''), and cnidocytes are sometimes referred to as nematocytes. It is unclear whether the relationship between dinoflagellate and cnidarian nematocysts is a case of convergent evolution or common descent, although molecular evidence has been interpreted as supporting an endosymbiotic origin for cnidarian nematocysts. In polykrikoids the nematocyst is found associated with another extrusive organelle called the taeniocyst, a complex that has been described as synapomorphic for the genus (biology), genus ''Polykrikos''. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnodiniales
The Gymnodiniales are an order of dinoflagellates, of the class Dinophyceae. Members of the order are known as gymnodinioid or gymnodinoid (terms that can also refer to any organism of similar morphology). 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." Of the families in the order, the Polykrikaceae and Warnowiaceae are well known for possessing exceptionally complex assemblies of organelles, such as nematocysts, trichocysts, and pistons. The Warnowiaceae uniquely possess an ocelloid, an extremely complex light-sensitive subcellular structure composed of mitochondria and plastid The plastid (Greek: πλαστός; plastós: formed, molded – plural plastids ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinophyceae
Dinophyceae is a class of dinoflagellates. Taxonomy * Class Dinophyceae Pascher 1914 eridinea Ehrenberg 1830 stat. nov. Wettstein; Blastodiniphyceae Fensome et al. 1993 orthog. emend.** Order Haplozoonales aplozooidea Poche 1913*** Family Haplozoonaceae Chatton 1920 ** Order Akashiwales *** Family Akashiwaceae ** Order Blastodiniales Chatton 1906 lastodinida Chatton 1906*** Family Blastodiniaceae Cavers 1913 ** Order Apodiniales *** Family Apodiniaceae Chatton 1920 ** Order Dinotrichales Pascher 1914 *** Family Crypthecodiniaceae Biecheler 1938 ex Chatton 1952 *** Family Dinotrichaceae Pascher 1914 ** Order Phytodiniales T. Christ. 1962 ex Loeblich 1970 inococcales Pascher 1914; Suessiales Fensome & al. 1993; Dinamoebales *** Family † Suessiaceae Fensome et al. 1993 *** Family Phytodiniaceae Klebs 1912 inococcaceae Fott 1960; Hemidiniaceae Bourrelly 1970; Borghiellaceae Moestrup, Lindberg & Daugbjerg 2009*** Family Symbiodiniaceae Fensome & al. 1993 ooxant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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