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Mediolabrus
''Mediolabrus'' is a genus of centric diatoms within the family Thalassiosiraceae. Known ''Mediolabrus'' species live planktonically in brackish and fresh water. This genus, together with the related '' Minidiscus'', includes some of the smallest diatom species with diameters as small as 1.9 μm (in '' M.'' '' comicus''). Taxonomy Genus ''Mediolabrus'' was erected in 2020 based on molecular phylogenetics, by transferring three species from the genus '' Minidiscus''. Morphology and ultrastructure The lenticular or spherical cells, smaller than 10 μm, live solitarily or in flocks. The valves (ends of the siliceous shell) are domed, with sloping mantle (side of the valve). The areolae (regularly repeated pores) are internally covered by individual, radially continuous cribra (perforated plates) and lack typical foramens (large openings) externally. At the edge of the valve face or close to the mantle are several fultoportulae (tube-like pores). There is only one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediolabrus Comicus
''Mediolabrus comicus'', known previously as ''Minidiscus comicus'', is a species of nanophytoplanktonic centric diatoms within the family Thalassiosiraceae. Its cells have diameters as small as 1.9 ''μ''m, which makes ''M.'' ''comicus'' one of the smallest known diatoms and brings it near to the theoretical lower size limit for photosynthetic eukaryotes. Taxonomy ''Mediolabrus comicus'' was originally described as ''Minidiscus comicus'', but in 2020, it was transferred based on molecular phylogenetics to a newly erected genus ''Mediolabrus'', as its type species. Morphology and ultrastructure Cells of ''M.'' ''comicus'' have diameters between 1.9 and 6.0 μm. The larger cells are discoidal with flat valve faces (ends of the Frustule, siliceous shell), while the smaller ones are spherical or even oblong. Valve margins are very narrow and marginal areolae (small regularly repeated pores) terminate close to the valve edge. There are 6–8 areolae per 1&nbs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediolabrus Ocellatus
''Mediolabrus'' is a genus of centric diatoms within the family Thalassiosiraceae. Known ''Mediolabrus'' species live planktonically in brackish and fresh water. This genus, together with the related '' Minidiscus'', includes some of the smallest diatom species with diameters as small as 1.9 μm (in '' M.'' '' comicus''). Taxonomy Genus ''Mediolabrus'' was erected in 2020 based on molecular phylogenetics, by transferring three species from the genus '' Minidiscus''. Morphology and ultrastructure The lenticular or spherical cells, smaller than 10 μm, live solitarily or in flocks. The valves (ends of the siliceous shell) are domed, with sloping mantle (side of the valve). The areolae (regularly repeated pores) are internally covered by individual, radially continuous cribra (perforated plates) and lack typical foramens (large openings) externally. At the edge of the valve face or close to the mantle are several fultoportulae (tube-like pores). There is only one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassiosiraceae
Thalassiosiraceae is a family of diatoms in the order Thalassiosirales. The family of Thalassiosiraceae have the unique quality of having a flat valve face. These diatoms are common in brackish, nearshore, and open-ocean habitats, with approximately the same number of freshwater and marine species. Morphology and ultrastructure Thalassiosiraceae include some of the smallest known diatoms, such as the genera '' Minidiscus'' and ''Mediolabrus'' with diameters as small as 1.9 μm (in '' M. comicus''). Unlike Naviculaceae who are symmetrical in shape, some Thalassiosiraceae are tangentially undulate. Thalassiosiraceae are centric diatoms with fultoportulae (central tube passing through the valve and two or more satellite pores). These structures can often be mistaken for areolae present in many diatom families that can be found in different forms such as those in ''Navicula'' or ''Gomphoneis'' known as lineolate and punctate areolae''.'' Model organisms The species ''Thalassios ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smallest Organisms
The smallest organisms found on Earth can be determined according to various aspects of organism size, including volume, mass, height, length, or genome size. Given the incomplete nature of scientific knowledge, it is possible that the smallest organism is undiscovered. Furthermore, there is some debate over the definition of life, and what entities qualify as organisms; consequently the smallest known organisms (microrganisms) may be nanobes that can be 20 nanometers long. Microorganisms Obligate endosymbiotic bacteria The genome of '' Nasuia deltocephalinicola'', a symbiont of the European pest leafhopper, '' Macrosteles quadripunctulatus'', consists of a circular chromosome of 112,031 base pairs. The genome of '' Nanoarchaeum equitans'' is 491 Kbp nucleotides long. ''Pelagibacter ubique'' '' Pelagibacter ubique'' is one of the smallest known free-living bacteria, with a length of and an average cell diameter of . They also have the smallest free-living bacterium gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatom
A diatom (Neo-Latin ''diatoma'') is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of Earth's Biomass (ecology), biomass. They generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion tonnes of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The Protist shell, shells of dead diatoms are a significant component of marine sediment, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Depression, which was once made up of a system of fresh-water lakes. Diatoms are unicellular organisms: they occur either as solitary cells or in Colony (biology), colonies, which can take the shape of ribb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish, and baleen whales. Marine plankton include bacteria, archaea, algae, protozoa, microscopic fungi, and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. fresh water, Freshwater plankton are similar to marine plankton, but are found in lakes and rivers. Mostly, plankton just drift where currents take them, though some, like jellyfish, swim slowly but not fast enough to generally overcome the influence of currents. Although plankton are usually thought of as inhabiting water, there are also airborne versions that live part of their lives drifting in the at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brackish Water
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary, estuaries, or it may occur in brackish Fossil water, fossil aquifers. The word comes from the Middle Dutch root '':wikt:brak#Dutch, brak''. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the Osmotic power, salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it can be damaging to the environment (see article on shrimp farming, shrimp farms). Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more ofte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresh Water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mineral water, mineral-rich waters, such as chalybeate springs. Fresh water may encompass frozen water, frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ice pellets, sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranea (geography), subterranean subterranean river, rivers and underground lake, lakes. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of vascular plants and most insects, amphibians, reptiles, mammals and birds need fresh water to sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetics, phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in Taxonomy (biology), taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalassiosirales
''Thalassiosirales'' is an order of centric diatoms. As of 2015, the order contained 471 species. Species in the order Thalassiosirales are common in brackish, nearshore, and open-ocean habitats, with approximately the same number of freshwater and marine species. The Thalassiosirales species ''Thalassiosira pseudonana'' was chosen as the first eukaryotic marine phytoplankton for whole genome sequencing Whole genome sequencing (WGS), also known as full genome sequencing or just genome sequencing, is the process of determining the entirety of the DNA sequence of an organism's genome at a single time. This entails sequencing all of an organism's .... ''T. pseudonana'' was selected for this study because it is a model for diatom physiology studies, belongs to a genus widely distributed throughout the world's oceans, and has a relatively small genome at 34 mega base pairs. Scientists are researching on diatom light absorption, using the marine diatom ''Thalassiosira''. Ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
