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Freshwater Fish Of Australia
Freshwater fish of Australia are limited to approximately 280 species, even though the Australian continent is larger than the contiguous United States. The small scale of species found in Australian inland waters is in some part due to the dry conditions of the continent. Rainfall is sporadic over much of the continent, and fish cannot live in many of the desert regions of South Australia and Western Australia. Most freshwater species are found in tropical or subtropical regions. A large proportion of freshwater species are endemic to Australia. The family Percicthyidae (temperate perches) and other families suspected in reality to lie within it (e.g. Gadopsidae, Nannopercidae) have risen to prominence in and dominate many of its freshwater systems, in contrast to the Northern Hemisphere where freshwater fish faunas are overwhelmingly dominated by the carp family, Cyprinidae. (No cyprinid species is native to Australia). Due to the illegal introduction of carp (''Cyprinus carpio' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates, with deserts in the centre, tropical rainforests in the north-east, and mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approximately 65,000 years ago, during the last ice age.religious_traditions_in_the_world._Australia's_history_of_Australia.html" "title="The_Dreaming.html" ;"title="Aboriginal_Art.html" "title="he Story of Australia's People, Volume 1: The Rise and Fall of Ancient Australia, Penguin Books Australia Ltd., Vic. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contiguous United States
The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii (also the last ones admitted to the Union), and all other offshore insular areas, such as American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands. The colloquial term "Lower48" is used also, especially in relation to just Alaska (Hawaii is farther south). The related but distinct term continental United States includes Alaska (which is also on the continent of North America but separated from the 48 states by British Columbia and Yukon of Canada), but excludes the Hawaiian Islands and all U.S. territories in the Caribbean and the Pacific. The greatest distance (on a great-circle route) entirely within the contiguous U.S. is 2,802 miles (4,509 km), between Florida and the State of Washington; ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic (ecology)
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Carp
The Eurasian carp or European carp (''Cyprinus carpio''), widely known as the common carp, is a widespread freshwater fish of eutrophic waters in lakes and large rivers in Europe and Asia.Fishbase''Cyprinus carpio'' Linnaeus, 1758/ref>Arkive The native wild populations are considered vulnerable to extinction by the International Union for Conservation of Nature (IUCN), but the species has also been domesticated and introduced (see aquaculture) into environments worldwide, and is often considered a destructive invasive species, being included in the list of the world's 100 worst invasive species. It gives its name to the carp family, Cyprinidae. Taxonomy The two subspecies are: * ''Cyprinus carpio carpio'', native to much of Europe (notably the Danube and Volga rivers)Jian Feng Zhou, Qing Jiang Wu, Yu Zhen Ye & Jin Gou Tong (2003). Genetic divergence between ''Cyprinus carpio carpio'' and ''Cyprinus carpio haematopterus'' as assessed by mitochondrial DNA analysis, with emp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overfishing
Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the overfishing of sharks, has led to the upset of entire marine ecosystems. Types of overfishing include: growth overfishing, recruitment overfishing, ecosystem overfishing. The ability of a fishery to recover from overfishing depends on whether its overall carrying capacity and the variety of ecological conditions are suitable f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Introduced Fish In Australia
Due to its geographical situation and isolation Australia has distinct fish fauna, including many endemic species. From the 18th century, early colonisers began introducing a number of exotic species including mammals, plant, birds and fish. The introduction of such fish has led to serious ecological damage, most notable being the effect of common carp in the Murray-Darling Basin. Introduced carp now dominate the freshwater systems of southern Australia. While the damaging impact of carp is well recognised, little in the way of control measures have been employed to control their spread. Their ability to colonise almost any body of water, even those previously considered to be beyond their physical tolerances, is now well established. Control of exotic fish species is being undertaken by various government departments, though many problems are faced. Introduced trout species dominate the upland reaches of rivers in southeast Australia, and may have negative effects on u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richmond River Cod
The Richmond River cod was a form of ''Maccullochella'' cod, now believed to have been eastern freshwater cod, ''Maccullochella ikei'', that occurred naturally in the Richmond River system, an east coast river system in north-east New South Wales, Australia. Eastern freshwater cod in turn are a species of ''Maccullochella'' cod found in east coast drainages and originating from Murray cod, ''Maccullochella peelii'', that crossed the Great Dividing Range and entered east coast drainages from a river capture event between 0.62 and 1.62 million years ago (mean estimate 1.1 million years ago). Richmond River cod are extinct, from overfishing, habitat destruction including gross siltation, and whole-of-catchment scale bushfires and fish kill The term fish kill, known also as fish die-off, refers to a localized die-off of fish populations which may also be associated with more generalized mortality of aquatic life.University of Florida. Gainesville, FL (2005) ''Plant Management in F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brisbane River Cod
The Brisbane River cod was a unique form of ''Maccullochella'' cod that occurred naturally in the Brisbane River system, an east coast river system in south east Queensland, Australia. The Brisbane River Cod was known as the Bumgur (meaning blue cod) by the Jinibara people centred in the Kilcoy region and the junction of the Stanley and Brisbane Rivers. Their exact taxonomic status is not known, but based on several genetic studies it is suspected that Brisbane River Cod were a species intermediate between eastern freshwater cod (''Maccullochella ikei'') of the Clarence River and Richmond River systems in northern New South Wales and Mary River cod of the Mary River in central Queensland. All naturally occurring ''Maccullochella'' cod in east coast drainages ultimately originate from Murray cod, ''Maccullochella peelii'' that entered an east coast river system, likely the Clarence, via a natural river capture event somewhere between 0.62 and 1.62 million years ago (mean est ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered
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 assessi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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