|
Cisco (fish)
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 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 38&nb ... [...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 and in weight. Individuals can reach more than . They are silvery pink or purple iridescence, darker on the back and white on the belly. They may have a dark tip on the lower jaw. They have a large head and a conspicuous, large eye. Subspecies Two subspecies of kiyi have been recognised based on morphological characteristics and distribution. The nominate su ... [...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 hete ... [...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 o ... [...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 ... [...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 speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyprinid
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family. It includes the carps, the true minnows, and relatives like the barbs and barbels. Cyprinidae is the largest and most diverse fish family and the largest vertebrate animal family in general with about 3,000 species, of which only 1,270 remain extant, divided into about 370 genera. Cyprinids range from about 12 mm in size to the giant barb (''Catlocarpio siamensis''). By genus and species count, the family makes up more than two-thirds of the ostariophysian order Cypriniformes. The family name is derived from the Greek word ( 'carp'). Biology and ecology Cyprinids are stomachless fish with toothless jaws. Even so, food can be effectively chewed by the gill rakers of the specialized last gill bow. These pharyngeal teeth allow the fish to make chewing motions against a chewing plate formed by a bony process of the skull. The pharyngeal teeth are unique to each species and are used by scient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evolutionarily Significant Unit
An evolutionarily significant unit (ESU) is a population of organisms that is considered distinct for purposes of conservation. Delineating ESUs is important when considering conservation action. This term can apply to any species, subspecies, geographic race, or population. Often the term "species" is used rather than ESU, even when an ESU is more technically considered a subspecies or variety rather than a biological species proper. In marine animals the term "stock" is often used as well. Definition Definitions of an ESU generally include at least one of the following criteria:Jeffrey Conner, Daniel Hartl. ''A Primer of Ecological Genetics''. 2004, # Current geographic separation, # Genetic differentiation at neutral markers among related ESUs caused by past restriction of gene flow, or # Locally adapted phenotypic traits caused by differences in selection. Criterion 2 considers the gene flow between populations, measured by FST. A high degree of differentiation between tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sensu Lato
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular concept, but it also appears in expressions that indicate the convention or context of the usage. Common qualifiers ''Sensu'' is the ablative case of the noun ''sensus'', here meaning "sense". It is often accompanied by an adjective (in the same case). Three such phrases are: *''sensu stricto'' – "in the strict sense", abbreviation ''s.s.'' or ''s.str.''; *''sensu lato'' – "in the broad sense", abbreviation ''s.l.''; *''sensu amplo'' – "in a relaxed, generous (or 'ample') sense", a similar meaning to ''sensu lato''. Søren Kierkegaard uses the phrase ''sensu eminenti'' to mean "in the pre-eminent r most important or significantsense". When appropriate, comparative and superlative adjectives may also be used to convey the meaning ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
