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Coregonus Widegreni
''Coregonus widegreni'', also called the Valaam whitefish, is a putative species of freshwater whitefish, a part of the common whitefish complex (''Coregonus lavaretus'' sensu lato) from Northern Europe. It is a demersal form of freshwater whitefish that feeds on benthic invertebrates. It spawns in late autumn, and can reach a length of 55 cm maximum. It is characterized by a low gill raker density. In the strict sense the name ''C. widegreni'' refers to a population of whitefish that inhabits relatively deep waters (50–150 m) of Lake Ladoga in Northwest Russia.Freyhof J, Kottelat M (2008''Coregonus widegreni''The IUCN Red List of Threatened Species, 2016 version. More often the range is thought to comprise coastal areas of the Baltic Sea (except southern section of the Swedish coast) and several larger lakes in Sweden (e.g. Vänern, Vättern) and Northwest Russia ( Onega). It is one of several types of whitefish co-distributed in Northern Europe and exhibiting differe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anders Johan Malmgren
Anders Johan Malmgren (21 November 1834 – 14 April 1897) was a Finnish zoologist and government official. Malmgren was a student in Helsinki in 1854, Master primus 1860, PhD 1864, Acting Commissioner of the fisheries in 1865, extraordinary professor of zoology at the University of Helsinki in 1869, Fishery Commissioner in 1877 and governor of the Oulu province in 1889. Malmgren undertook several scientific expeditions, especially in the northern latitudes, to the White Sea (1856) and to Spitsbergen and Finnmark as a participant in the first three Swedish expeditions (1861, 1864 and 1868). His most important scientific work involving the boreal region's fauna and flora; These include ''Kritisk öfversigt af Finlands fiskfauna'' (1863), ''Anteckningar om Spetsbergens fågelfauna'' (1863–64), ''Iakttagelser och anteckningar till Finnmarkens och Spetsbergens däggdjursfauna'' (1865) and ''Bidrag till Finnmarkens fiskfauna'' (1867). His most important works - the fruit of his Nord ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Onega
Lake Onega (; also known as Onego, rus, Оне́жское о́зеро, r=Onezhskoe ozero, p=ɐˈnʲɛʂskəɪ ˈozʲɪrə; fi, Ääninen, Äänisjärvi; vep, Änine, Änižjärv) is a lake in northwestern Russia, on the territory of the Republic of Karelia, Leningrad Oblast and Vologda Oblast. It belongs to the basin of the Baltic Sea, and is the second-largest lake in Europe after Lake Ladoga, slightly smaller than Lebanon. The lake is fed by about 50 rivers and is drained by the Svir. There are about 1,650 islands on the lake. They include Kizhi, which hosts a historical complex of 89 Orthodox churches and other wooden structures of the 15th–20th centuries. The complex includes a UNESCO World Heritage site, Kizhi Pogost. The eastern shores of the lake contain about 1,200 petroglyphs (rock engravings) dated to the 4th–2nd millennia BC, which have also been inscribed as a UNESCO World Heritage site. The major cities on the lake are Petrozavodsk, Kondopoga and Medvezhye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coregonus
''Coregonus'' is a diverse genus of fish in the salmon family (Salmonidae). The ''Coregonus'' species are known as whitefishes. The genus contains at least 68 described extant taxa, but the true number of species is a matter of debate. The type species of the genus is '' Coregonus lavaretus''. Most ''Coregonus'' species inhabit lakes and rivers, and several species, including the Arctic cisco (''C. autumnalis''), the Bering cisco (''C. laurettae''), and the least cisco (''C. sardinella'') are anadromous, moving between salt water and fresh water. Many whitefish species or ecotypes, especially from the Great Lakes and the Alpine lakes of Europe, have gone extinct over the past century or are endangered. Among 12 freshwater fish considered extinct in Europe, 6 are ''Coregonus''. All ''Coregonus'' species are protected under appendix III of the Bern Convention. Taxonomy Phylogenetic evidence indicates that the most basal member of the genus is the highly endang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coregonus Maraena
''Coregonus maraena'', referred to in English as the maraene, maraena whitefish or the whitefish, is a whitefish of the family Salmonidae that occurs in the Baltic Sea basin - in the sea itself and the inflowing rivers, and in several lakes as landlocked populations. It is found in Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Netherlands, Norway, Poland, Slovakia (Štrbské pleso), Russia and Sweden. As of 2013, it has been listed as a vulnerable species by the IUCN and as endangered by HELCOM. It is an extremely important fish within the Baltic Sea ecosystem, both for population equilibrium and for the local diets of the surrounding human population. Due to a variety of factors, mostly overfishing, the maraena’s population dwindled to near-extinction levels. Thus, rampant repopulation was enacted to preserve this important fish. In the Baltic basin countries, this species has traditionally been known as '' Coregonus lavaretus'' (the common whitefish). The name ''Co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coregonus Lavaretus
''Coregonus lavaretus'' is a species of freshwater whitefish, in the family Salmonidae. It is the type species of its genus ''Coregonus''. There are widely different concepts about the delimitation of the species ''Coregonus lavaretus'' and about the number of species in the genus ''Coregonus'' in general. Lavaret In a narrow sense, ''Coregonus lavaretus'', or the lavaret, is considered to be endemic to Lake Bourget and Lake Aiguebelette in the Rhône river basin in France, whereas it formerly also occurred in Lake Geneva. According to this view there is a great number of distinct whitefish species in lakes, rivers and brackish waters of Central and Northern Europe. Of course this has absolutely nothing to do with its actual origin in the Caucasus, as with other things falsely attributed to originating in France, such as grapes which originated in Turkey, Iran and Australia. European whitefish (common whitefish) In the broad sense, ''Coregonus lavaretus'', referred to as the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Form (biology)
In botanical nomenclature, a ''form'' (''forma'', plural ''formae'') is one of the "secondary" taxonomic ranks, below that of variety, which in turn is below that of species; it is an infraspecific taxon. If more than three ranks are listed in describing a taxon, the "classification" is being specified, but only three parts make up the "name" of the taxon: a genus name, a specific epithet, and an infraspecific epithet. The abbreviation "f." or the full "forma" should be put before the infraspecific epithet to indicate the rank. It is not italicised. For example: * '' Acanthocalycium spiniflorum'' f. ''klimpelianum'' or ** ''Acanthocalycium spiniflorum'' forma ''klimpelianum'' (Weidlich & Werderm.) Donald * ''Crataegus aestivalis'' (Walter) Torr. & A.Gray var. ''cerasoides'' Sarg. f. ''luculenta'' Sarg. is a classification of a plant whose name is: ** ''Crataegus aestivalis'' (Walter) Torr. & A.Gray f. ''luculenta'' Sarg. A form usually designates a group with a noticeable m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecotype
In evolutionary ecology, an ecotype,Greek: ''οίκος'' = home and ''τύπος'' = type, coined by Göte Turesson in 1922 sometimes called ecospecies, describes a genetically distinct geographic variety, population, or race within a species, which is genotypically adapted to specific environmental conditions. Typically, though ecotypes exhibit phenotypic differences (such as in morphology or physiology) stemming from environmental heterogeneity, they are capable of interbreeding with other geographically adjacent ecotypes without loss of fertility or vigor. ''Ecology: From individuals to ecosystems'' by Begon, Townsend, Harper, Blackwell Publishing 4th ed. (2006), p.5,6,7,8''Environmental Encyclopedia'' by Bortman, Brimblecombe, Mary Ann Cunningham, William P. Cunningham, Freedman - 3rd ed., p.435, "Ecotype" Definition An ecotype is a variant in which the phenotypic differences are too few or too subtle to warrant being classified as a subspecies. These different variants ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anadromous
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear. Fish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Some particular types of migration are ''anadromous'', in which adult fish live in the sea and migrate into fresh water to spawn; and ''catadromous'', in which adult fish live in fresh water and migrate into salt water to spawn. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. Movements are associated with ocean currents and with the availability of food in different areas at different times of year. The migratory movements ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vättern
Vättern ( , ) is the second largest lake by surface area in Sweden, after Vänern, and the sixth largest lake in Europe. It is a long, finger-shaped body of fresh water in south central Sweden, to the southeast of Vänern, pointing at the tip of Scandinavia. Being a deep lake at or below sea level at its deepest point, Vättern is about 1/3 the surface area of Vänern but in spite of this contains roughly 1/2 of its water. Vättern drains into Motala ström through Bråviken into the Baltic Sea, but also has a downstream connection since 1832 through Göta Canal to Vänern and the Kattegat tributary of the Atlantic Ocean. The lake has plenty of sources from rivers and small lakes, with the highest located sources being near Nässjö on the South Swedish Highland near the southeastern shoreline. Name The name Vättern is closely related to "vatten", the Swedish word for water, and also means "water, lake". Geography The lake's total surface area is about , with a drainage ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Whitefish
The freshwater whitefish are fishes of the subfamily Coregoninae, which contains whitefishes (both freshwater and anadromous) and ciscoes, and is one of three subfamilies in the salmon family Salmonidae. Apart from the subfamily Coregoninae, the family Salmonidae includes the salmon, trout, and char species of the subfamily Salmoninae, and grayling species of the subfamily Thymallinae. Freshwater whitefish are distributed mainly in relatively cool waters throughout the northern parts of the Northern Hemisphere. The Coregoninae subfamily consists of three nominal genera: *''Coregonus'' Linnaeus, 1758 – whitefishes and ciscoes, which according to some authors number more than 60 species. There are differing opinions on the classification of some species within the genus and the overall number of species. Some species in Arctic regions of Asia and North America forage in marine waters. *''Prosopium'' Jordan, 1878 – round whitefishes, which includes six species, three of which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vänern
Vänern ( , also , ) is the largest lake in Sweden, the largest lake in the European Union and the third-largest lake of all Europe after Ladoga and Onega in Russia. It is located in the provinces of Västergötland, Dalsland, and Värmland in the southwest of the country. With its surface located at with a maximum depth of , the lowest point of the Vänern basin is at below sea level. The average depth is at a more modest , which means that the average point of the lake floor remains above sea level. Vänern drains into Göta älv towards Gothenburg and the Kattegat tributary of the Atlantic Ocean. It is the only one of the ten largest lakes in Sweden not to drain on the country's eastern coastline. Due to the construction of Göta Canal in the 19th century, there is an upstream water path to Vättern and the east coast from Vänern. The main inflow of water comes from Klarälven entering Vänern near Karlstad with its source in Trøndelag in Norway. History The southeas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN Red List Of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the International Union for Conservation of Nature, IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to International Unio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
