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Salvelinus Tolmachoffi
''Salvelinus tolmachoffi'', also known as Yessey lake charr, is a freshwater species of fish in the salmon family. It is endemic to Lake Yessey of the Khatanga river basin of the arctic Russia. In 2007, the fish was listed as endangered by IUCN due to over-fishing and poor management of the water body. Description Yessey lake charr can grow to a recorded maximum length of 37.0 cm (14.6 inches). The fish lives at or near the bottom of the lake. The head and back of the fish are blue-black, while the sides of the body are dark-gray with a golden tint and the belly is pale yellow. There are numerous red spots on the sides of the body. The species feed on gammarus ''Gammarus'' is an amphipod crustacean genus in the family Gammaridae. It contains more than 200 described species, making it one of the most species-rich genera of crustaceans. Different species have different optimal conditions, particularly i ..., copepods, chironomid larvae, and fish. Yessey lake charr spawn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lev Berg
Lev Semyonovich Berg, also known as Leo S. Berg (russian: Лев Семёнович Берг; 14 March 1876 – 24 December 1950) was a leading Russian geographer, biologist and ichthyologist who served as President of the Soviet Geographical Society between 1940 and 1950. He is known for his own evolutionary theory, nomogenesis (a form of orthogenesis incorporating mutationism) as opposed to the theories of Darwin and Lamarck. Life Lev Berg was born in Bessarabia in a Jewish family, the son of Simon Gregoryevich Berg, a notary, and Klara Lvovna Bernstein-Kogan. He graduated from the Second Kishinev Gymnasium in 1894. Like some of his relatives, Berg converted to Christianity in order to pursue his studies at Moscow State University. At Moscow University, Berg studied hydrobiology and geography. He later studied ichthyology and in 1928 was awarded he was also a member of the Russian Academy of Sciences. Lev Berg graduated from the Moscow State University in 1898. Between 190 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmonidae
Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefishes, graylings, taimens and lenoks, which are collectively known as the salmonids ("salmon-like fish"). The Atlantic salmon (''Salmo salar''), whose Latin name became that of its genus ''Salmo'', is also the source of the family and order names. Salmonids have a relatively primitive appearance among the teleost fish, with the pelvic fins being placed far back, and an adipose fin towards the rear of the back. They have slender bodies, with rounded scales and forked tails, and their mouths contain a single row of sharp teeth. Although the smallest species is just long as an adult, most are much larger, with the largest reaching . All salmonids spawn in fresh water of upper reaches of rivers and creeks, but in many cases, the fish spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Yessey
Lake Yessey () is a large freshwater lake in Evenkiysky District, Krasnoyarsk Krai, north-central part of Russia. The lake is located in the Central Siberian Plateau, to the west of the course of the Kotuy river. A tributary of the Kotuy flows out of the southern end of the lake. It has an area of . Fauna The lake is rich in fish. The endangered Lake Yessey Char, '' Salvelinus tolmachoffi'', is found in the waters of the lake. See also *List of lakes of Russia References Yessey Yessey (russian: Ессе́й, sah, Дьэһэй) is a rural locality (a settlement) in Evenkiysky District of Krasnoyarsk Krai, Russia, located on the shore of Lake Yessey. History The historian of Siberia, B.O. Dolgikh, writes that in 16 ... Central Siberian Plateau Evenkiysky District {{KrasnoyarskKrai-geo-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Khatanga (river)
The Khatanga (russian: Хатанга) is a river in Krasnoyarsk Krai in Russia. The river is navigable. The river port of Khatanga is located on the river. Course It begins at the confluence of the rivers Kotuy and Kheta. The Khatanga is long ( including its headwater Kotuy); the area of its basin is . It flows into the of the , forming an |
Arctic Circle
The Arctic Circle is one of the two polar circles, and the most northerly of the five major circles of latitude as shown on maps of Earth. Its southern equivalent is the Antarctic Circle. The Arctic Circle marks the southernmost latitude at which, on the December solstice, the shortest day of the year in the northern hemisphere, the sun will not rise all day, and on the June solstice, the longest day of the year in the northern hemisphere, the sun will not set. These phenomena are referred to as polar night and midnight sun respectively, and the further north one progresses, the more pronounced these effects become. For example, in the Russian port city of Murmansk, three degrees above the Arctic Circle, the sun does not rise for 40 successive days in midwinter. The position of the Arctic Circle is not fixed and currently runs north of the Equator. Its latitude depends on the Earth's axial tilt, which fluctuates within a margin of more than 2° over a 41,000-year period, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered Species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration. Human activity is a significant cause in causing some species to become endangered. Conservation status The conservation status of a species indicates the likelihood that it will become extinct. Multiple factors are considered when assessing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demersal Fish
Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word ''demersal'' comes from the Latin ''demergere'', which means ''to sink''. Demersal fish are bottom feeders. They can be contrasted with pelagic fish which live and feed away from the bottom in the open water column. Demersal fish fillets contain little fish oil (one to four percent), whereas pelagic fish can contain up to 30 percent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gammarus
''Gammarus'' is an amphipod crustacean genus in the family Gammaridae. It contains more than 200 described species, making it one of the most species-rich genera of crustaceans. Different species have different optimal conditions, particularly in terms of salinity, and different tolerances; ''Gammarus pulex'', for instance, is a purely freshwater species, while ''Gammarus locusta'' is estuarine, only living where the salinity is greater than 25‰. Species of ''Gammarus'' are the typical " scuds" of North America and range widely throughout the Holarctic. A considerable number are also found southwards into the Northern Hemisphere tropics, particularly in Southeast Asia. Species The following species are included: Four new species were found in 2018 on the Tibetan Plateau. Four more new species were described from the Chihuahuan Desert in 2021. *''Gammarus abscisus'' G. Karaman, 1973 *''Gammarus abstrusus'' Hou, Platvoet & Li, 2006 *'' Gammarus acalceolatus'' Pinkster, 1970 *'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copepod
Copepods (; meaning "oar-feet") are a group of small crustaceans found in nearly every freshwater and saltwater habitat (ecology), habitat. Some species are planktonic (inhabiting sea waters), some are benthos, benthic (living on the ocean floor), a number of species have parasitic phases, and some continental species may live in limnoterrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests, bogs, springs, ephemeral ponds, and puddles, damp moss, or water-filled recesses (phytotelmata) of plants such as bromeliads and pitcher plants. Many live underground in marine and freshwater caves, sinkholes, or stream beds. Copepods are sometimes used as Ecological indicator, biodiversity indicators. As with other crustaceans, copepods have a larval form. For copepods, the egg hatches into a Crustacean larvae#Nauplius, nauplius form, with a head and a tail but no true thorax or abdomen. The larva molts several times until it resembles the adult an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chironomidae
The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species superficially resemble mosquitoes, but they lack the wing scales and elongated mouthparts of the Culicidae. The name Chironomidae stems from the Ancient Greek word ''kheironómos'', "a pantomimist". Common names and biodiversity This is a large taxon of insects; some estimates of the species numbers suggest well over 10,000 world-wide. Males are easily recognized by their plumose antennae. Adults are known by a variety of vague and inconsistent common names, largely by confusion with other insects. For example, chironomids are known as "lake flies" in parts of Canada and Lake Winnebago, Wisconsin, but "bay flies" in the areas near the bay of Green Bay, Wisconsin. They are called "sand flies", "muckleheads", "muffleheads", "Canadian so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salvelinus
''Salvelinus'' is a genus of Salmonidae, salmonid fish often called char or charr; some species are called "trout". ''Salvelinus'' is a member of the subfamily Salmoninae within the family Salmonidae. The genus has a northern circumpolar distribution, and most of its members are typically cold-water fish that primarily inhabit fresh waters. Many species also migrate to the sea. Most char may be identified by light-cream, pink, or red spots over a darker body. Scales tend to be small, with 115-200 along the lateral line. The pectoral, pelvic, anal, and the lower aspect of caudal fins are trimmed in snow white or cream leading edges. Many members of this genus are popular sport fish, and a few, such as lake trout (''S. namaycush'') and arctic char (''S. alpinus'') are objects of commercial fisheries and/or aquaculture. Occasionally, such fish escape and become invasive species. Deepwater char are small species of char living below 80 m in the deep areas of certain lakes. They are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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