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Salmonids
Salmonidae (, ) is a family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), char, graylings, freshwater whitefishes, taimens and lenoks, all coldwater mid-level predatory fish that inhabit the subarctic and cool temperate waters of the Northern Hemisphere. The Atlantic salmon (''Salmo salar''), whose Latin name became that of its genus ''Salmo'', is also the eponym of the family and order names. Salmonids have a relatively primitive appearance among 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 tail fins, and their mouths contain a single row of sharp teeth. Although the smallest salmonid species is just long for adults, most salm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trout
Trout (: trout) is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera '' Oncorhynchus'', ''Salmo'' and ''Salvelinus'', all of which are members of the subfamily Salmoninae in the family Salmonidae. The word ''trout'' is also used for some similar-shaped but non-salmonid fish, such as the spotted seatrout/speckled trout (''Cynoscion nebulosus'', which is actually a croaker). Trout are closely related to salmon and have similar migratory life cycles. Most trout are strictly potamodromous, spending their entire lives exclusively in freshwater lakes, rivers and wetlands and migrating upstream to spawn in the shallow gravel beds of smaller headwater creeks. The hatched fry and juvenile trout, known as ''alevin'' and ''parr'', will stay upstream growing for years before migrating down to larger waterbodies as maturing adults. There are some anadromous species of trout, such as the steelhead (a coastal subs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmon
Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native to tributary, tributaries of the North Atlantic (''Salmo'') and North Pacific (''Oncorhynchus'') basins. ''Salmon'' is a colloquial or common name used for fish in this group, but is not a scientific name. Other closely related fish in the same family include trout, Salvelinus, char, Thymallus, grayling, Freshwater whitefish, whitefish, lenok and Hucho, taimen, all coldwater fish of the subarctic and cooler temperate regions with some sporadic endorheic populations in Central Asia. Salmon are typically fish migration, anadromous: they hatch in the shallow gravel stream bed, beds of freshwater headstreams and spend their juvenile fish, juvenile years in rivers, lakes and freshwater wetlands, migrate to the ocean as adults and live like sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thymallus
''Thymallus'', commonly known as graylings, is a genus of freshwater ray-finned fish and the only genus within the subfamily Thymallinae of the family Salmonidae. Although all ''Thymallus'' species can be generically called graylings, without specific qualification the term "grayling" typically refers to the type species '' Thymallus thymallus'', the European grayling. Name The name of the genus ''Thymallus'' first given to grayling (''T. thymallus'') described in the 1758 edition of ''Systema Naturae'' by Swedish zoologist Carl Linnaeus originates from the faint smell of the herb thyme, which emanates from the flesh. ''Thymallus'' derives from the Greek θύμαλλος, "thyme smell". Species According to FishBase, 14 species are placed in this genus. However, views differ on their taxonomic rank. * '' Thymallus arcticus'' ( Pallas, 1776) - Arctic grayling * '' Thymallus baicalensis'' Dybowski, 1874 - Baikal black grayling * '' Thymallus brevipinnis'' Svetovid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmo Salar
The Atlantic salmon (''Salmo salar'') is a species of ray-finned fish in the family Salmonidae. It is the third largest of the Salmonidae, behind Hucho taimen, Siberian taimen and Pacific Chinook salmon, growing up to a meter in length. Atlantic salmon are found in the northern Atlantic Ocean and in rivers that flow into it. Most populations are anadromous, hatching in streams and rivers but moving out to sea as they grow where they mature, after which the adults seasonally move upstream again to spawn. When the mature fish re-enter rivers to spawn, they change in colour and appearance. Some populations of this fish only migrate to large lakes, and are "landlocked", spending their entire lives in freshwater. Such populations are found throughout the range of the species. Unlike Pacific species of salmon, ''S. salar'' is iteroparous, which means it can survive spawning and return to sea to repeat the process again in another year with 5–10% returning to the sea to spawn again ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subarctic
The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of hemiboreal regions and covering much of Alaska, Canada, Iceland, the north of Fennoscandia, Northwestern Russia, Siberia, and the Cairngorms. Generally, subarctic regions fall between 50°N and 70°N latitude, depending on local climates. Precipitation is usually low, and vegetation is characteristic of the taiga. Daylight at these latitudes is quite extreme between summer and winter due to its high latitude. Near the summer solstice for instance, subarctic regions can experience an all-night period of either civil, nautical, or astronomical twilight (or in the northern reaches full daylight), since the sun never dips more than 18 degrees below the horizon. Noctilucent clouds are best observed within this range of latitude. Climate and soils Subarctic temperatures are above for at least one and at most three months of the year. Precipitation tends to be low due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coldwater Fish
The term coldwater fish can have different meanings in different contexts. * In the context of fishkeeping, it refers to ornamental fish species that tolerate the temperatures of a typical indoor aquarium well and do not require a heater to remain active, as opposed to tropical fish whom need a heater to survive in the room temperatures of temperate climates; * In the context of ecology and fishing, it refers to fish species that prefer to inhabit waterbodies or depth zones with much lower temperatures than the average temperate water. Salmonids (e.g. salmon, trout, char and graylings) are a classic example of such types of fish. Fishkeeping Most or all ornamental fish species are able to tolerate temperatures as low as or lower than room temperature, with most stenothermic tropical species having critical thermal minimums of around 10-12 °C. Although these fish are capable of surviving in unheated aquaria, their temperature preferences may vary. For example, koi, go ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trophic Level
The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it is from the start of the chain. A food web starts at trophic level 1 with primary producers such as plants, can move to herbivores at level 2, carnivores at level 3 or higher, and typically finish with apex predators at level 4 or 5. The path along the chain can form either a one-way flow or a part of a wider food "web". Ecological communities with higher biodiversity form more complex trophic paths. The word ''trophic'' derives from the Ancient Greek, Greek wikt:τροφή, τροφή (trophē) referring to food or nourishment. History The concept of trophic level was developed by Raymond Lindeman (1942), based on the terminology of August Thienemann (1926): "producers", "consumers", and "reducers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predatory Fish
Predatory fish are hypercarnivorous fish that actively prey upon other fish or aquatic animals, with examples including shark, billfish, barracuda, alligator gar, tuna, dolphinfish, walleye, perch and salmon. Some omnivorous fish, such as the red-bellied piranha, can occasionally also be predatory, although they are not strictly regarded as obligately predatory fish. Populations of large predatory fish in the global oceans were estimated to be about 10% of their pre-industrial levels by 2003, and they are most at risk of extinction; there was a disproportionate level of large predatory fish extinctions during the Cretaceous–Paleogene extinction event 66 million years ago. Creation of marine reserves has been found to restore populations of large predatory fish such as the ''Serranidae'' — groupers and sea bass. Predatory fish switch between types of prey in response to variations in their abundance. Such changes in preference are disproportionate and are selec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Hemisphere
The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar System as Earth's North Pole. Due to Earth's axial tilt of 23.439281°, there is a seasonal variation in the lengths of the day and night. There is also a seasonal variation in temperatures, which lags the variation in day and night. Conventionally, winter in the Northern Hemisphere is taken as the period from the December solstice (typically December 21 UTC) to the March equinox (typically March 20 UTC), while summer is taken as the period from the June solstice through to the September equinox (typically on 23 September UTC). The dates vary each year due to the difference between the calendar year and the Year#Astronomical years, astronomical year. Within the Northern Hemisphere, oceanic currents can change the weather patterns that aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temperate
In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout the year and more distinct seasonal changes compared to tropical climates, where such variations are often small; they usually differ only in the amount of precipitation. In temperate climates, not only do latitude, latitudinal positions influence temperature changes, but various sea currents, prevailing wind direction, continentality (how large a landmass is) and altitude also shape temperate climates. The Köppen climate classification defines a climate as "temperate" C, when the mean temperature is above but below in the coldest month to account for the persistence of frost. However, some adaptations of Köppen set the minimum at . Continental climate, Continental climates are classified as D and considered to be varie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taimen
''Hucho'' is a genus of large piscivorous salmonid fish known as taimens (from Finnish , 'trout', through ), and is closely related to Pacific trout and lenoks (all belonging to the same tribe in the subfamily Salmoninae). Native to the cold rivers and other freshwater habitats in Eurasia, they are threatened by overfishing and habitat loss. The earliest fossil remains of this genus are known from the Late Oligocene to middle Miocene of the Vitim Plateau in Russia. Younger remains are also known from the Late Miocene of Ukraine and the Late Pleistocene of Germany. Fossil specimens of a ''Hucho''-like salmonid have been recovered from the Clarkia fossil beds and other localities from the late Neogene of western North America, suggesting they may have potentially inhabited North America too. Species The currently recognized species in this genus are: In addition, the Sakhalin taimen was formerly placed in this genus, but genetics Genetics is the study of genes, ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
