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Huso Baerii
The Siberian sturgeon (''Huso baerii'') is a species of sturgeon in the family Acipenseridae. It is most present in all of the major Siberian river basins that drain northward into the Kara, Laptev and East Siberian Seas, including the Ob, Yenisei (which drains Lake Baikal via the Angara River) Lena, and Kolyma Rivers. It was also found in Kazakhstan and China in the Irtysh River, a major tributary of the Ob, though wild populations are extirpated in China. The species epithet honors the German Russian biologist Karl Ernst von Baer. Taxonomy Prior to 2025, it was placed in the genus ''Acipenser'', but this placement was found to be paraphyletic, and it is more accurately placed in the genus ''Huso''. The Siberian sturgeon has previously been divided into two subspecies. However, recent studies suggest they may be monotypic, forming continuous genetically connected populations throughout their vast range.Ruban, G.I. (1999). he Siberian Sturgeon ''Acipenser baerii'' Brandt (St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Von Brandt
Johann Friedrich von Brandt (25 May 1802 – 15 July 1879) was a German-Russian natural history, naturalist, who worked mostly in Russia. Brandt was born in Jüterbog and educated at a Gymnasium (school), gymnasium in Wittenberg and the Humboldt University of Berlin, University of Berlin. In 1831 he emigrated to Russia, and soon was appointed director of the Zoological Museum of the St Petersburg Academy of Sciences. Brandt encouraged the collection of native animals, many of which were not represented in the museum. Many specimens began to arrive from the expeditions of Nikolai Alekseevich Severtzov, Severtzov, Nikolai Przhevalsky, Przhevalsky, Aleksandr Fyodorovich Middendorf, Middendorff, Leopold von Schrenck, Schrenck and Gustav Radde. He described several birds collected by Russian explorers off the Pacific Coast of North America, including Brandt's cormorant, red-legged kittiwake and spectacled eider. As a paleontologist, Brandt ranks among the best. He was also an entomo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Name (zoology)
In zoological nomenclature, the specific name (also specific epithet, species epithet, or epitheton) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description. For example, the scientific name for humans is ''Homo sapiens'', which is the species name, consisting of two names: ''Homo'' is the " generic name" (the name of the genus) and ''sapiens'' is the "specific name". Etymology Historically, ''specific name'' referred to the combination of what are now called the generic and specific names. Carl Linnaeus, who formalized binomial nomenclature, made explicit distinctions between specific, generic, and trivial names. The generic name was that of the genus, the first in the binomial, the trivial name was the second name in the binomial, and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Loss
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease in biodiversity and Abundance (ecology), species numbers. Habitat destruction is in fact the leading cause of biodiversity loss and species extinction worldwide. Humans contribute to habitat destruction through the Exploitation of natural resources, use of natural resources, agriculture, industrial production and urbanization (urban sprawl). Other activities include mining, logging and trawling. Environmental factors can contribute to habitat destruction more indirectly. Geological processes, climate change, introduced species, introduction of invasive species, ecosystem nutrient depletion, water pollution, water and noise pollution are some examples. Loss of habitat can be preceded by an initial habitat fragmentation. Fragmentation and lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Main Stem
In hydrology, a main stem or mainstem (also known as a trunk) is "the primary downstream segment of a river, as contrasted to its tributaries". The mainstem extends all the way from one specific headwater to the outlet of the river, although there are multiple ways to determine which headwater (or first-order tributary) is the source of the main stem. Water enters the main stem from the river's drainage basin, the land area through which the mainstem and its tributaries flow.. A drainage basin may also be referred to as a ''watershed'' or ''catchment''. Hydrological classification systems assign numbers to tributaries and mainstems within a drainage basin. In the Strahler number, a modification of a system devised by Robert E. Horton in 1945, channels with no tributaries are called "first-order" streams. When two first-order streams meet, they are said to form a second-order stream; when two second-order streams meet, they form a third-order stream, and so on. In the Horton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenga River
The Selenga ( ) or Selenge is a major river in Mongolia and Buryatia, Russia. Originating from its headwater tributaries, the Ider and the Delger mörön, it flows for before draining into Lake Baikal. The Selenga therefore makes up the most distant headwaters of the Yenisey- Angara river system. Carrying of water into Lake Baikal, it makes up almost half of the riverine inflow into the lake, and forms a wide delta of when it reaches the lake. Periodic annual floods are a feature of the Selenga River. The floods can be classified as “ordinary”, “large” or “catastrophic” based on the degree of impact. Of the twenty-six documented floods that occurred between 1730 and 1900, three were “catastrophic”. The three “catastrophic” floods were the floods of 1830, 1869 and 1897. The Selenga River basin is a semi-arid region that is in area. It is part of the Arctic Ocean Basin and is located in northern Mongolia. Stone implement artifacts found on the Selenga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baikal Sturgeon
The Siberian sturgeon (''Huso baerii'') is a species of sturgeon in the family Acipenseridae. It is most present in all of the major Siberian river basins that drain northward into the Kara, Laptev and East Siberian Seas, including the Ob, Yenisei (which drains Lake Baikal via the Angara River) Lena, and Kolyma Rivers. It was also found in Kazakhstan and China in the Irtysh River, a major tributary of the Ob, though wild populations are extirpated in China. The species epithet honors the German Russian biologist Karl Ernst von Baer. Taxonomy Prior to 2025, it was placed in the genus ''Acipenser'', but this placement was found to be paraphyletic, and it is more accurately placed in the genus ''Huso''. The Siberian sturgeon has previously been divided into two subspecies. However, recent studies suggest they may be monotypic, forming continuous genetically connected populations throughout their vast range.Ruban, G.I. (1999). he Siberian Sturgeon ''Acipenser baerii'' Brand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spawn (biology)
Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is known as spawning. The vast majority of aquatic and amphibious animals reproduce through spawning. These include the following groups: * Bony fishes * Crustaceans (such as crabs, shrimps, etc.) *Mollusks (such as oysters, octopus, squid) *Echinoderms (such as sea urchins, sea stars, sea cucumbers, etc.) * Amphibians (such as frogs, toads, salamanders, newts) * Aquatic insects (such as dragonflies, mayflies, mosquitoes) *Coral, which are living colonies of tiny, aquatic organisms—not plants, as they are sometimes perceived to be. Corals, while appearing sedentary or botanical by nature, actually spawn by releasing clouds of sperm and egg cells into the water column, where the two mix. As a general rule, aquatic or semiaquatic reptiles, birds, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anoxic Waters
Anoxic waters are areas of sea water, fresh water, or groundwater that are depleted of dissolved oxygen. The US Geological Survey defines anoxic groundwater as those with dissolved oxygen concentration of less than 0.5 milligrams per litre. Anoxic waters can be contrasted with hypoxic waters, which are low (but not lacking) in dissolved oxygen. Often, hypoxia is defined as waters that have less than 2 milligrams per litre of dissolved oxygen. This condition is generally found in areas that have restricted water exchange. In most cases, oxygen is prevented from reaching the deeper levels by a physical barrier, as well as by a pronounced density stratification, in which, for instance, denser, colder or hypersaline waters rest at the bottom of a basin. Anoxic conditions will occur if the rate of oxidation of organic matter by bacteria is greater than the supply of dissolved oxygen. Anoxic waters are a natural phenomenon, and have occurred throughout geological history. The Permia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxon
In biology, a taxon (back-formation from ''taxonomy''; : taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion, especially in the context of rank-based (" Linnaean") nomenclature (much less so under phylogenetic nomenclature). If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were presumably set forth in prehistoric times by hunter-gatherers, as suggested by the fairly sophisticated folk taxonomies. Much later, Aristotle, and later st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subspecies
In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated as subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific name, infraspecific ranks, such as variety (botany), variety, may be named. In bacteriology and virology, under standard International Code of Nomenclature of Prokaryotes, bacterial nomenclature and virus clas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Huso
''Huso'' is a genus of sturgeons from eastern Europe, Asia, and eastern North America. The genus name is derived from ''wikt:huso, hūso'', the Old High German and Medieval Latin word for "sturgeon", which is also ancestral to ''wikt:Hausen, Hausen'', the German name for the Beluga (sturgeon), beluga sturgeon. Taxonomy Until 2025, ''Huso'' was defined as containing two giant-sized species: the Beluga (sturgeon), beluga from western Eurasia, and the Kaluga (fish), kaluga from East Asia. However, this placement was long found to be Polyphyly, polyphyletic, with the kaluga grouping with other East Asian sturgeon species. In contrast, a large number of Eurasian and two North American species were found to form a large clade with ''H. huso''. In addition, the latter clade was found to be more closely related to the morphologically unusual ''Pseudoscaphirhynchus'' than to any other sturgeon clade. In 2025, this taxonomic conundrum was resolved by reclassifying the kaluga and other P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
