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Karenia Mikimotoi
''Karenia mikimotoi'' is a dinoflagellate species from the genus '' Karenia''. Its first appearance was in Japan in 1935 and since then, it has appeared in other parts of the world such as the east coast of the United States, Norway, and the English Channel. Description ''Karenia mikimotoi'' has yellow-brown chloroplasts and, like other species in its genus, is able to activate photosynthetically. It lacks thecal plates, and is more ovular. Blooms usually form during warmer months. The toxicity of ''Karenia mikimotoi'' is not fully understood, whereas other species in ''Karenia'' have identified toxins that are shown to kill marine life. For example, '' Karenia brevis'' has brevetoxins. It is believed that its killing effects are due to a combination of the creation of an anoxic environment by the physical bloom itself in addition to some sort of toxin. New toxins called gymnocin A and B were recently discovered,Silke, J., et al''Karenia mikimotoi'': An exceptional dinoflagella ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinoflagellate
The dinoflagellates (Greek δῖνος ''dinos'' "whirling" and Latin ''flagellum'' "whip, scourge") are a monophyletic group of single-celled eukaryotes constituting the phylum Dinoflagellata and are usually considered algae. 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 (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 pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karenia (dinoflagellate)
''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. Taxonomy The genus ''Karenia'' is named for Dr. Karen Steidinger for her exceptional contributions to dinoflagellate research. She has spent many decades researching ''Karenia brevis''. 12 species have been described in the genus ''Karenia'' thus far: * ''Karenia asterichroma'' * ''Karenia bicuneiformis'' * ''Karenia brevis'' * ''Karenia brevisulcata'' * ''Karenia concordia'' * ''Karenia cristata'' * ''Karenia digitata'' * ''Karenia longicanalis'' * ''Karenia mikimotoi'' * ''Karenia papilionacea'' * ''Kare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroplast
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in the energy-storage molecules ATP and NADPH while freeing oxygen from water in the cells. The ATP and NADPH is then used to make organic molecules from carbon dioxide in a process known as the Calvin cycle. Chloroplasts carry out a number of other functions, including fatty acid synthesis, amino acid synthesis, and the immune response in plants. The number of chloroplasts per cell varies from one, in unicellular algae, up to 100 in plants like ''Arabidopsis'' and wheat. A chloroplast is characterized by its two membranes and a high concentration of chlorophyll. Other plastid types, such as the leucoplast and the chromoplast, contain little chlorophyll and do not carry out photosynthesis. Chloroplasts are highly dynamic—they circulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karenia Brevis
''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. Each cell has two flagella that allow it to move through the water in a spinning motion. ''K. brevis'' is unarmored, and does not contain peridinin. Cells are between 20 and 40 μm in diameter. ''K. brevis'' naturally produces a suite of potent neurotoxins collectively called brevetoxins, which cause gastrointestinal and neurological problems in other organisms and are responsible for large die-offs of marine organisms and seabirds. History ''Karenia brevis'' was named for Dr. Karen A. Steidinger in 2001, and was previously known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Red Tide
A harmful algal bloom (HAB) (or excessive algae growth) is an algal bloom that causes negative impacts to other organisms by production of natural phycotoxin, algae-produced toxins, mechanical damage to other organisms, or by other means. HABs are sometimes defined as only those algal blooms that produce toxins, and sometimes as any algal bloom that can result in severely lower oxygen saturation, oxygen levels in natural waters, killing organisms in marine habitats, marine or fresh waters. Blooms can last from a few days to many months. After the bloom dies, the microorganism, microbes that decompose the dead algae use up more of the oxygen, generating a "dead zone (ecology), dead zone" which can cause fish kill, fish die-offs. When these zones cover a large area for an extended period of time, neither fish nor plants are able to survive. Harmful algal blooms in marine environments are often called "red tides". It is sometimes unclear what causes specific HABs as their occurrence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic Zone
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "the depths." Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the shore line (intertida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lugworm
The lugworm or sandworm (''Arenicola marina'') is a large marine worm of the phylum Annelida. Its coiled castings are a familiar sight on a beach at low tide but the animal itself is rarely seen except by those who, from curiosity or to use as fishing bait, dig the worm out of the sand. In the UK, the lugworm species ''Arenicola marina'' is commonly known as the blow lugworm, and rarely exceeds . There is a second species of UK lugworm ''Arenicola defodiens'' commonly called the black lugworm. As well as growing larger than blow lugworm (in line with descriptions for Europe and North America lugworm below) they are generally much darker, often totally black. They can be distinguished by the different wormcasts they produce - ''Arenicola defodiens'' makes a spiral cast, while that of ''Arenicola marina'' is jumbled. When fully grown, the lugworm of the coasts of Europe is up to long and in diameter. Other species on the North American coast range from . The body is like that of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cockle (bivalve)
A cockle is an edible marine bivalve mollusc. Although many small edible bivalves are loosely called cockles, true cockles are species in the family Cardiidae. MolluscaBase eds. (2022). MolluscaBase. Cardiidae Lamarck, 1809. Accessed through: World Register of Marine Species at: https://www.marinespecies.org/aphia.php?p=taxdetails&id=229 on 2022-02-09 True cockles live in sandy, sheltered beaches throughout the world. The distinctive rounded shells are bilaterally symmetrical, and are heart-shaped when viewed from the end. Numerous radial, evenly spaced ribs are a feature of the shell in most but not all genera (for an exception, see the genus ''Laevicardium'', the egg cockles, which have very smooth shells). The shell of a cockle is able to close completely (i.e., there is no "gap" at any point around the edge). Though the shell of a cockle may superficially resemble that of a scallop because of the ribs, cockles can be distinguished from scallops morphologically in that co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Department For Environment, Food And Rural Affairs
The Department for Environment, Food and Rural Affairs (Defra) is a department of His Majesty's Government responsible for environmental protection, food production and standards, agriculture, fisheries and rural communities in the United Kingdom. Concordats set out agreed frameworks for co operation, between it and the Scottish Government, Welsh Government and Northern Ireland Executive, which have devolved responsibilities for these matters in their respective nations. Defra also leads for the United Kingdom on agricultural, fisheries and environmental matters in international negotiations on sustainable development and climate change, although a new Department of Energy and Climate Change was created on 3 October 2008 to take over the last responsibility; later transferred to the Department for Business, Energy and Industrial Strategy following Theresa May's appointment as Prime Minister in July 2016. Creation The department was formed in June 2001, under the leadersh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyridine
Pyridine is a basic heterocyclic organic compound with the chemical formula . It is structurally related to benzene, with one methine group replaced by a nitrogen atom. It is a highly flammable, weakly alkaline, water-miscible liquid with a distinctive, unpleasant fish-like smell. Pyridine is colorless, but older or impure samples can appear yellow, due to the formation of extended, unsaturated polymeric chains, which show significant electrical conductivity. The pyridine ring occurs in many important compounds, including agrochemicals, pharmaceuticals, and vitamins. Historically, pyridine was produced from coal tar. As of 2016, it is synthesized on the scale of about 20,000 tons per year worldwide. Properties Physical properties The molecular electric dipole moment is 2.2 debyes. Pyridine is diamagnetic and has a diamagnetic susceptibility of −48.7 × 10−6 cm3·mol−1. The standard enthalpy of formation is 100.2 kJ·mol−1 in the liquid phase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
