Carp are various species of oily freshwater fish from the family Cyprinidae, a large group of fish native to Europe and Asia. The cypriniformes are traditionally grouped with the Characiformes and Gymnotiformes to create the superorder Ostariophysi, since these groups share some common features; these features include being found predominantly in fresh water and possessing Weberian ossicles, an anatomical structure derived from the first five anterior-most vertebrae, their corresponding ribs and neural crests. The third anterior-most pair of ribs is in contact with the extension of the labyrinth and the posterior with the swim bladder; the function is poorly understood, but this structure is presumed to take part in the transmission of vibrations from the swim bladder to the labyrinth and in the perception of sound, which would explain why the Ostariophysi have such a great capacity for hearing. Most cypriniformes have scales and teeth on the inferior pharyngeal bones which may be modified in relation to the diet.
Tribolodon is the only cyprinid genus. Several species return to fresh water to spawn. All of the other cypriniformes have a wide geographical range; some consider all cyprinid fishes carp, the family Cyprinidae itself is known as the carp family. In colloquial use, carp refers only to several larger cyprinid species such as Cyprinus carpio, Carassius carassius, Ctenopharyngodon idella, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis. Carp have long been an important food fish to humans. Several species such as the various goldfish breeds and the domesticated common carp variety known as koi have been popular ornamental fishes; as a result, carp have been introduced to various locations, though with mixed results. Several species of carp are listed as invasive species by the U. S. Department of Agriculture, worldwide, large sums of money are spent on carp control. At least some species of carp are able to survive for months with no oxygen by metabolizing glycogen to form lactic acid, converted into ethanol and carbon dioxide.
The ethanol diffuses into the surrounding water through the gills. In 1653 Izaak Walton wrote in The Compleat Angler, "The Carp is the queen of rivers. Carp are variable in terms of angling value. In Europe when not fished for food, they are eagerly sought by anglers, being considered prized coarse fish that are difficult to hook; the UK has a thriving carp angling market. It is the fastest growing angling market in the UK, has spawned a number of specialised carp angling publications such as Carpology, Advanced carp fishing and Total Carp, informative carp angling web sites, such as Carpfishing UK. In the United States, carp are classified as a rough fish, as well as damaging to naturalized exotic species, but with sporting qualities. Carp have long suffered from a poor reputation in the United States as undesirable for angling or for the table since they are an invasive species out-competing more desirable local game fish. Nonetheless, many states' departments of natural resources are beginning to view the carp as an angling fish instead of a maligned pest.
Groups such as Wild Carp Companies, American Carp Society, the Carp Anglers Group promote the sport and work with fisheries departments to organize events to introduce and expose others to the unique opportunity the carp offers freshwater anglers. Various species of carp have been domesticated and reared as food fish across Europe and Asia for thousands of years; these various species appear to have been domesticated independently, as the various domesticated carp species are native to different parts of Eurasia. Aquaculture has been pursued in China for at least 2,400 years. A tract by Fan Li in the fifth century BC details many of the ways carp were raised in ponds; the common carp, Cyprinus carpio, is from Central Europe. Several carp species were domesticated in East Asia. Carp that are from South Asia, for example catla and mrigal, are known as Indian carp, their hardiness and adaptability have allowed domesticated species to be propagated all around the world. Although the carp was an important aquatic food item, as more fish species have become available for the table, the importance of carp culture in Western Europe has become less important.
Demand has declined due to the appearance of more desirable table fish such as trout and salmon through intensive farming, environmental constraints. However, fish production in ponds is still a major form of aquaculture in Central and Eastern Europe, including the Russian Federation, where most of the production comes from low or intermediate-intensity ponds. In Asia, the farming of carp continues to surpass the total amount of farmed fish volume of intensively sea-farmed species, such as salmon and tuna. Selective breeding programs for the common carp include improvement in growth and resistance to disease. Experiments carried out in the USSR used crossings of broodstocks to increase genetic diversity, selected the species for traits such as growth rate, exterior traits and viability, and/or adaptation to environmental conditions such as variations in temperature. Selected carp for fast growth and tolerance to cold, the Ropsha carp; the results showed a 30 to 77.4% improvement of cold tolerance, but did not provide any data for growth
The emu is the second-largest living bird by height, after its ratite relative, the ostrich. It is endemic to Australia where it is the largest native bird and the only extant member of the genus Dromaius; the emu's range covers most of mainland Australia, but the Tasmanian, Kangaroo Island and King Island subspecies became extinct after the European settlement of Australia in 1788. The bird is sufficiently common for it to be rated as a least-concern species by the International Union for Conservation of Nature. Emus are soft-feathered, flightless birds with long necks and legs, can reach up to 1.9 metres in height. Emus can travel great distances, when necessary can sprint at 50 km/h, they take in copious amounts of water when the opportunity arises. Breeding takes place in May and June, fighting among females for a mate is common. Females can lay several clutches of eggs in one season; the male does the incubation. The eggs hatch after around eight weeks, the young are nurtured by their fathers.
They reach full size after around six months, but can remain as a family unit until the next breeding season. The emu is an important cultural icon of Australia, appearing on the coat of various coins; the bird features prominently in Indigenous Australian mythology. Emus were first reported as having been seen by Europeans when explorers visited the western coast of Australia in 1696; the birds were known on the eastern coast before 1788. The birds were first mentioned under the name of the "New Holland cassowary" in Arthur Phillip's Voyage to Botany Bay, published in 1789 with the following description: This is a species differing in many particulars from that known, is a much larger bird, standing higher on its legs and having the neck longer than in the common one. Total length seven feet two inches; the bill is not different from that of the common Cassowary. The plumage in general consists of a mixture of brown and grey, the feathers are somewhat curled or bent at the ends in the natural state: the wings are so short as to be useless for flight, indeed, are scarcely to be distinguished from the rest of the plumage, were it not for their standing out a little.
The long spines which are seen in the wings of the common sort, are in this not observable,—nor is there any appearance of a tail. The legs are stout, formed much as in the Galeated Cassowary, with the addition of their being jagged or sawed the whole of their length at the back part; the species was named by ornithologist John Latham in 1790 based on a specimen from the Sydney area of Australia, a country, known as New Holland at the time. He collaborated on Phillip's book and provided the first descriptions of, names for, many Australian bird species. In his original 1816 description of the emu, the French ornithologist Louis Jean Pierre Vieillot used two generic names, first Dromiceius and Dromaius, it has been a point of contention since as to which name should be used. Most modern publications, including those of the Australian government, use Dromaius, with Dromiceius mentioned as an alternative spelling; the etymology of the common name "emu" is uncertain, but is thought to have come from an Arabic word for large bird, used by Portuguese explorers to describe the related cassowary in Australia and New Guinea.
Another theory is that it comes from the word "ema", used in Portuguese to denote a large bird akin to an ostrich or crane. In Victoria, some terms for the emu were Barrimal in the Dja Dja Wurrung language, myoure in Gunai, courn in Jardwadjali; the birds were known as murawung or birabayin to the local Eora and Darug inhabitants of the Sydney basin. The emu was long classified, with its closest relatives the cassowaries, in the family Casuariidae, part of the ratite order Struthioniformes. However, an alternate classification was proposed in 2014 by Mitchell et al. based on analysis of mitochondrial DNA. This splits off the Casuariidae into their own order, the Casuariformes, includes only the cassowaries in the family Casuariidae, placing the emus in their own family, Dromaiidae; the cladogram shown below is from their study. Two different Dromaius species were present in Australia at the time of European settlement, one additional species is known from fossil remains; the insular dwarf emus, D. n. baudinianus and D. n. minor present on Kangaroo Island and King Island both became extinct shortly after the arrival of Europeans.
D. n. diemenensis, another insular dwarf emu from Tasmania, became extinct around 1865. However, the mainland subspecies, D. n. novaehollandiae, remains common. The population of these birds varies from decade to de
Themeda triandra is a perennial tussock-forming grass widespread in Africa, Australia and the Pacific. In Australia it is known as kangaroo grass and in East Africa and South Africa it is known as red grass and red oat grass or as rooigras in Afrikaans, it does not do well benefits from occasional fire. Themeda triandra is a grass which grows in dense tufts 0.5 metres wide. It flowers in summer, producing large red-brown spikelets on branched stems; the leaves are 10–30 centimetres in length and 1–8 millimetres wide but can exceed 10–50 centimetres long and 2–5 millimetres wide. Its inflorescence is compounded, fasciculated, is 10–30 centimetres long and composed of a single raceme, it pedicels are oblong and are 0.5 mm long while its lemma is 25–70 millimetres long and is both apical and geniculate. The column of lemma's awn is twisted. Themeda triandra was first formally described in 1775 by Peter Forsskål who published the description in Flora Aegyptiaco-Arabica. There are many synonyms of this species.
The specific epithet is derived from the Ancient Greek word andros meaning "man" or "male" with the prefix tri meaning "three". Themeda triandra is found across Asia, Africa and the Pacific. In Australia, it is found in all of the territories, it grows predominantly in open woodland communities. It is a significant species in temperate grasslands in Australia, a habitat considered to be endangered or threatened in various parts of the country; the young growth is palatable to stock. T. triandra seed has been used as a famine food in Africa. It serves as a food source for several avian species, including the long-tailed widowbird, it is occasionally used as an ornamental plant. Themeda triandra. PlantzAfrica
The elevation of a geographic location is its height above or below a fixed reference point, most a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface. The term elevation is used when referring to points on the Earth's surface, while altitude or geopotential height is used for points above the surface, such as an aircraft in flight or a spacecraft in orbit, depth is used for points below the surface. Elevation is not to be confused with the distance from the center of the Earth. Due to the equatorial bulge, the summits of Mount Everest and Chimborazo have the largest elevation and the largest geocentric distance. GIS or geographic information system is a computer system that allows for visualizing, manipulating and storage of data with associated attributes. GIS offers better understanding of relationships of the landscape at different scales. Tools inside the GIS allow for manipulation of data for spatial cartography. A topographical map is the main type of map used to depict elevation through use of contour lines.
In a Geographic Information System, digital elevation models are used to represent the surface of a place, through a raster dataset of elevations. Digital terrain models are another way to represent terrain in GIS. USGS is developing a 3D Elevation Program to keep up with growing needs for high quality topographic data. 3DEP is a collection of enhanced elevation data in the form of high quality LiDAR data over the conterminous United States and the U. S. territories. There are three bare earth DEM layers in 3DEP which are nationally seamless at the resolution of 1/3, 1, 2 arcseconds; this map is derived from GTOPO30 data that describes the elevation of Earth's terrain at intervals of 30 arcseconds. It uses shading instead of contour lines to indicate elevation. Height Orthometric height Hypsography Geodesy Geodesy of North America Sea Level Datum of 1929 National Geodetic Vertical Datum of 1929 North American Vertical Datum of 1988 List of European cities by elevation List of highest mountains List of highest towns by country Normaal Amsterdams Peil Normalhöhennull Physical geography Table of the highest major summits of North America Temperature lapse rate Topographic isolation Topographic prominence Topography Vertical pressure variation U.
S. National Geodetic Survey website Geodetic Glossary @ NGS NGVD 29 to NAVD 88 online elevation converter @ NGS United States Geological Survey website Geographical Survey Institute Downloadable ETOPO2 Raw Data Database Downloadable ETOPO5 Raw Data Database Find the elevation of any place
In biology, the canopy is the aboveground portion of a plant community or crop, formed by the collection of individual plant crowns. In forest ecology, canopy refers to the upper layer or habitat zone, formed by mature tree crowns and including other biological organisms. Sometimes the term canopy is used to refer to the extent of the outer layer of leaves of an individual tree or group of trees. Shade trees have a dense canopy that blocks light from lower growing plants. Canopy structure is the spatial arrangement of a plant canopy. Leaf Area Index, leaf area per unit ground area, is a key measure used to understand and compare plant canopies, it is taller than the understory layer. Dominant and co-dominant canopy trees form the uneven canopy layer. Canopy trees are able to photosynthesize rapidly due to abundant light, so it supports the majority of primary productivity in forests; the canopy layer provides protection from strong winds and storms, while intercepting sunlight and precipitation, leading to a sparsely vegetated understory layer.
Forest canopies are home to unique fauna not found in other layers of forests. The highest terrestrial biodiversity resides in the canopy of tropical rainforests. Many rainforest animals have evolved to live in the canopy, never touch the ground; the canopy of a rainforest is about 10m thick, intercepts around 95% of sunlight. The canopy is below the emergent layer, a sparse layer of tall trees one or two per hectare. With an abundance of water and a near ideal temperature in rainforests and nutrients are two factors that limit tree growth from the understory to the canopy. In the permaculture and forest gardening community, the canopy is the highest of seven layers. Canopy Canopy research Canopy walkway Hemispherical photography Stratification Treefall gap Wildfire Crown shyness Tropical forest Rainforest size-asymmetric competition Lowman, M. D. and H. B. Rinker. 2004. Forest Canopies. Academic Press. ISBN 0-12-457553-6, ISBN 978-0-12-457553-0 Moffett, M. W. 1994. The High Frontier: Exploring the Tropical Rainforest Canopy.
Harvard University Press, Cambridge, MA. Russell, G. B. Marshall, P. G. Jarvis. 1990. Plant Canopies: Their Growth and Function. Cambridge University Press. ISBN 0-521-39563-1, ISBN 978-0-521-39563-2 International Canopy Access Network
Marine life, or sea life or ocean life, is the plants and other organisms that live in the salt water of the sea or ocean, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. Marine organisms produce oxygen. Shorelines are in part shaped and protected by marine life, some marine organisms help create new land. Most life forms evolved in marine habitats. By volume, oceans provide about 90 percent of the living space on the planet; the earliest vertebrates appeared in the form of fish, which live in water. Some of these evolved into amphibians which spend portions of their lives in water and portions on land. Other fish evolved into land mammals and subsequently returned to the ocean as seals, dolphins or whales. Plant forms such as kelp and algae grow in the water and are the basis for some underwater ecosystems. Plankton, phytoplankton, are key primary producers forming the general foundation of the ocean food chain. Marine invertebrates exhibit a wide range of modifications to survive in poorly oxygenated waters, including breathing tubes and gills.
Fish have gills instead of lungs, although some species such as the lungfish, have both. Marine mammals, such as dolphins, whales and seals need to surface periodically to breathe air; some amphibians are able to absorb oxygen through their skin. A total of 230,000 documented marine species exist, including about 20,000 species of marine fish, with some two million marine species yet to be documented. Marine species range in size from the microscopic, including plankton and phytoplankton which can be as small as 0.02 micrometres, to huge cetaceans, including the blue whale – the largest known animal reaching up to 33 metres in length. Marine microorganisms, including bacteria and viruses, constitute about 70% of the total marine biomass. There is no life without water – the "solvent of life"; the Nobel Prize winner Albert Szent-Györgyi referred to water as the mater und matrix: the mother and womb of life. The abundance of surface water on Earth is a unique feature in the Solar System. Earth's hydrosphere consists chiefly of the oceans, but technically includes all water surfaces in the world, including inland seas, lakes and underground waters down to a depth of 2,000 metres The deepest underwater location is Challenger Deep of the Mariana Trench in the Pacific Ocean, having a depth of 10,911 metres.
The mass of the oceans is 1.35×1018 metric tons, or about 1/4400 of Earth's total mass. The oceans cover an area of 3.618×108 km2 with a mean depth of 3682 m, resulting in an estimated volume of 1.332×109 km3. If all of Earth's crustal surface was at the same elevation as a smooth sphere, the depth of the resulting world ocean would be about 2.7 kilometres. About 97.5% of the water on Earth is saline. Most fresh water -- about 68.7 % -- is present as ice in ice glaciers. The average salinity of Earth's oceans is about 35 grams of salt per kilogram of seawater. Most of the salt in the ocean comes from the erosion of rocks on land; some salts are extracted from cool igneous rocks. The oceans are a reservoir of dissolved atmospheric gases, which are essential for the survival of many aquatic life forms. Sea water has an important influence on the world's climate, with the oceans acting as a large heat reservoir. Shifts in the oceanic temperature distribution can cause significant weather shifts, such as the El Niño-Southern Oscillation.
Altogether the ocean occupies 71 percent of the world surface, averaging nearly 3.7 kilometres in depth. By volume, the ocean provides about 90 percent of the living space on the planet; the science fiction writer Arthur C. Clarke has pointed out it would be more appropriate to refer to planet Earth as planet Ocean; the Earth is about 4.54 billion years old. The earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago, during the Eoarchean Era after a geological crust started to solidify following the earlier molten Hadean Eon. Microbial mat fossils have been found in 3.48 billion-year-old sandstone in Western Australia. Other early physical evidence of a biogenic substance is graphite in 3.7 billion-year-old metasedimentary rocks discovered in Western Greenland as well as "remains of biotic life" found in 4.1 billion-year-old rocks in Western Australia. According to one of the researchers, "If life arose quickly on Earth … it could be common in the universe."All organisms on Earth are descended from a common ancestor or ancestral gene pool.
Energetic chemistry is thought to have produced a self-replicating molecule around 4 billion years ago, half a billion years the last common ancestor of all life existed. The current scientific consensus is that the complex biochemistry that makes up life came from simpler chemical reactions; the beginning of life may have included self-replicating molecules such as RNA and the assembly of simple cells. In 2016 scientists reported a set of 355 genes from the last universal common ancestor of all life, including microorganisms, living on Earth. Current species are a stage in the process of evolution, with their diversity the product of a long series of speciation and extinction events; the common descent of organisms was first deduced from four simple facts about organisms: First, they have geographic distributions that cannot be explained by local adaptation. Second, the diversity of life is not a set of unique organisms, but organisms that share morphological similarities. Third, vestigial traits with no clear purp