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Ciscoes
The ciscoes (or ''ciscos'') are salmonid fish that differ from other members of the genus in having upper and lower jaws of approximately equal length and high gill raker counts. These species have been the focus of much study recently, as researchers have sought to determine the relationships among species that appear to have evolved very recently. The term ''cisco'' is also specifically used of the North American species ''Coregonus artedi'', also known as lake herring. In previous taxonomic classifications, the ciscoes have been identified as a subgenus ''Leucichthys'' of the genus ''Coregonus''. Based on molecular data this is not a natural classification however, as the ciscoes are polyphyletic, comprising two different lineages within the freshwater whitefishes.Bernatchez L, Colombani F, Dodson JJ (1991Phylogenetic relationships among the subfamily Coregoninae as revealed by mitochondrial DNA restriction analysis''Journal of Fish Biology 39 (Suppl A):283-290. Continental ... [...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 highl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coregonus Artedi
''Coregonus artedi'', commonly known as the cisco, is a North American species of freshwater whitefish in the family Salmonidae. The number of species and definition of species limits in North American ciscoes is a matter of debate. Accordingly, ''Coregonus artedi'' may refer either in a narrow sense to one of the several types of cisco found e.g. in the Great Lakes, or in a broad sense to the complex of all ciscoes in continental North American lakes, ''Coregonus artedi'' sensu lato. ''Coregonus artedi'', narrow sense Narrowly defined, ''Coregonus artedi'' is known variously with the common names cisco, northern cisco, lake herring, chub or tullibee and its Anishinaabe name ''Odoonibiins''. It is a pelagic fish occurring in the midwater zone of cold water lakes in North America. In the northern and western parts of its range it is also found in large rivers. This species occasionally grows as large as 40 cm and 2.3 kg (five pounds), but is more commonly 28 to 3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coregonus Hoyi
''Coregonus hoyi'', also known as the bloater, is a species or form of freshwater whitefish in the family Salmonidae. It is a silvery-coloured herring-like fish, long. It is found in most of the Great Lakes and in Lake Nipigon, and inhabits underwater slopes. This fish is not to be confused with the extinct deepwater cisco (''Coregonus johannae''), a large fish that shared a common name with the bloater. Description The bloater is a small, silvery-coloured whitefish with a pink and purple iridescence. It has a greenish tinge above, and a whitish belly. It is very similar to the kiyi, from which it may be distinguished by its lighter upper lip and smaller eye. Its body is deepest at its middle, it has small and pale fins, and it has 40–47 long gill rakers. The discoverer of the bloater, P. R. Hoy, thought it to be "the most beautiful of the white fish". It reaches a maximum total length of and commonly is . Distribution The bloater is native to all of the Great Lakes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kiyi
The kiyi (''Coregonus kiyi'') is a species of freshwater whitefish, a deepwater cisco, endemic to the Great Lakes of North America. It previously inhabited Lake Superior, Lake Michigan, Lake Huron and Lake Ontario, but is now believed to persist only in Lake Superior where it is common. The various deepwater ciscos are also called chubs (not to be confused with the various species of Cyprinidae also called chubs). The kiyi is part of the large group of related northern ciscos known as the ''Coregonus artedi'' complex. Description The kiyi is one of the smaller ciscos. Adult kiyi average approximately in total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ... and in weight. Individuals can reach more than . They are silvery pink or purple iridescence, darker on the ba ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blackfin Cisco
The blackfin cisco (''Coregonus nigripinnis'') was a North American salmonid fish in the freshwater whitefish sub-family Coregoninae. This silvery, deep-bodied fish with black fins, large eyes, a blunt snout and a terminal mouth, was one of the largest forms of ciscoes. The blackfin cisco used to inhabit the Great Lakes of North America until recently, but has been reported to have gone extinct. The blackfin cisco is a member of the '' C. artedi'' complex, whose taxonomy has not yet been resolved, and it may not represent a valid species. Taxonomy The species was first mentioned by P.R. Hoy 1872, attributing Gill as the species authority, but Gill's manuscript was never published. The first valid description of this species is attributed to James Wood Milner in 1874. The taxonomy of ''C. nigripinnis'', along with other ciscoes in the '' C. artedi'' complex, is unresolved. ''C. nigripinnis'' was recognized by W.N. Koelz in 1929 to consist of four subspecies, but he had diffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bering Cisco
The Bering cisco or Lauretta whitefish (''Coregonus laurettae'') is a freshwater whitefish found in Alaska and part of Russia. It is often considered to be the same species as the more common Arctic cisco (''Coregonus autumnalis''). Description The Bering cisco has an elongate, compressed body. It is silvery-coloured, with a brownish or greenish back. Its pelvic and pectoral fins are almost clear, and its other fins are spotted white. It is distinguished from the Arctic cisco by its smaller number of gill rakers. It reaches a maximum length of . Distribution The Bering cisco is found in Alaska from Cook Inlet on the south coast to Oliktok Point on the Arctic coast. It occurs on the Yukon River as far upstream as Dawson City, on the Porcupine River, and in the lakes of the Brooks Range. There are some reports of Bering ciscoes from the Chukchi Peninsula and the Kamchatka Peninsula, these presumably being migrants from Alaska. Ecology The Bering cisco is usually found in riv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Cisco
Arctic cisco (''Coregonus autumnalis''), also known as omul russian: Омуль, is an anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia, Alaska and Canada. It has a close freshwater relative in several lakes of Ireland, known as the pollan, alternatively regarded as conspecific with it, or as a distinct species. Taxonomy The freshwater omul of Lake Baikal, formerly considered a subspecies ''Coregonus autumnalis migratorius'' of the Arctic cisco, has no close genetic relationship to it and is now classified as a separate species, ''Coregonus migratorius''. Description The Arctic cisco have a relatively small head with a non-prominent snout. They have metallic silver body, a brown or dark green back, and nearly colorless fins. They have neither spots nor teeth on their jaws. They do have a patch of teeth on their tongue. They can reach 50 cm (20 in) in length and can weight up to 2 kg (4.4 lbs), but are usually less than 40 cm (16 in) in le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conservation Genetics
Conservation genetics is an interdisciplinary subfield of population genetics that aims to understand the dynamics of genes in populations principally to avoid extinction. Therefore, it applies genetic methods to the conservation and restoration of biodiversity. Researchers involved in conservation genetics come from a variety of fields including population genetics, molecular ecology, biology, evolutionary biology, and systematics. Genetic diversity is one of the three fundamental levels of biodiversity, so it is directly important in conservation. Genetic variability influences both the health and long-term survival of populations because decreased genetic diversity has been associated with reduced fitness, such as high juvenile mortality, diminished population growth, reduced immunity, and ultimately, higher extinction risk. Genetic diversity Genetic diversity is the variability of genes in a species. A number of means can express the level of genetic diversity: observed he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lauretta Whitefish
The Bering cisco or Lauretta whitefish (''Coregonus laurettae'') is a freshwater whitefish found in Alaska and part of Russia. It is often considered to be the same species as the more common Arctic cisco (''Coregonus autumnalis''). Description The Bering cisco has an elongate, compressed body. It is silvery-coloured, with a brownish or greenish back. Its pelvic and pectoral fins are almost clear, and its other fins are spotted white. It is distinguished from the Arctic cisco by its smaller number of gill rakers. It reaches a maximum length of . Distribution The Bering cisco is found in Alaska from Cook Inlet on the south coast to Oliktok Point on the Arctic coast. It occurs on the Yukon River as far upstream as Dawson City, on the Porcupine River, and in the lakes of the Brooks Range. There are some reports of Bering ciscoes from the Chukchi Peninsula and the Kamchatka Peninsula, these presumably being migrants from Alaska. Ecology The Bering cisco is usually found in riv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alewife (fish)
The alewife (''Alosa pseudoharengus'') is an anadromous species of herring found in North America. It is one of the "typical" North American shads, attributed to the subgenus ''Pomolobus'' of the genus ''Alosa''. As an adult it is a marine species found in the northern West Atlantic Ocean, moving into estuaries before swimming upstream to breed in freshwater habitats, but some populations live entirely in fresh water. It is best known for its invasion of the Great Lakes by using the Welland Canal to bypass Niagara Falls. Here, its population surged, peaking between the 1950s and 1980s to the detriment of many native species of fish. In an effort to control them biologically, Pacific salmon were introduced, only partially successfully. As a marine fish, the alewife is a US National Marine Fisheries Service "Species of Concern". Description Alewife reach a maximum length of about 40 cm (16 in), but have an average length of about 25 cm (10 in). The front of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Smelt
The rainbow smelt (''Osmerus mordax'') is a North American species of fish of the family Osmeridae. Walleye, trout, and other larger fish prey on these smelt. The rainbow smelt prefer juvenile ciscoes, zooplankton such as calanoid copepods (''Leptodiaptomus ashlandi'', '' L. minutus'', '' L. sicilis''), and other small organisms, but are aggressive and will eat almost any fish they find. They are anadromous spring spawners and prefer clean streams with light flow and light siltation. The rainbow smelt face several barriers. They are weak swimmers and struggle to navigate fish ladders preventing them from making it past dams to the headwater streams where they spawn. The rise in erosion and dams helped to decimate the smelt population in the 1980s. There are currently plans to try to reduce damming and to help control erosion. Description The body of the rainbow smelt is slender and cylindrical. It has a silvery, pale green back and is iridescent purple, blue, and pink on the s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Lamprey
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish". Description The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, round and sucker-like, and as wide or wider than the head; sharp teeth are arranged in many concentric circular rows. There are seven branchial or gill-like openings behind the eye. Sea lampreys are olive or brown-yellow on the dorsal and lateral part of the body, with some black marblings, with lighter coloration on the belly. Adults can reach a length of up to and a body weight up to . Etymology The etymology of the genus name ''Petromyzon'' is from '' petro-'' "stone" and '' myzon'' "sucking"; ''marinus'' is Latin for "of the sea". Distribution and habitat The species is found in the northern and western Atlantic Ocean along the shores of Europe and North America, in the western Mediterranean Sea, the Black Sea, and as an invasive spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
