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Hatcheries
A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish, poultry or even turtles. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled conditions; alternatively, it may be for economic reasons (i.e. to enhance food supplies or fishery resources). Fish hatcheries Fish hatcheries are used to cultivate and breed a large number of fish in an enclosed environment. Fish farms use hatcheries to cultivate fish to sell for food, or ornamental purposes, eliminating the need to find the fish in the wild and even providing some species outside their natural season. They raise the fish until they are ready to be eaten or sold to aquarium stores. Other hatcheries release the juvenile fish into a river, lake or the ocean to support commercial, tribal, or recreational fishing or to supplement the natural numbers of threatened or endangered species, a practice known as fish stocking. Resea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Stocking
Fish stocking is the practice of raising fish in a hatchery and releasing them into a river, lake or ocean to supplement existing populations or to create a population where previously none exists. Stocking may be done for the benefit of commercial, recreational or tribal heritage fishing, but may also be done to restore or increase the population of threatened or endangered fish in a body of water closed to fishing. Fish stocking may be conducted by governmental agencies in public waters, or by private groups in private waters. When in public waters, fish stocking creates a common-pool resource which is rivalrous in nature but non-excludable. Thus, on public grounds, all can enjoy the benefits of fishing so long as fish continue to be stocked. History Fish stocking is a practice that dates back hundreds of years. According to biologist Edwin Pister, widespread trout stocking dates back to the 1800s. For the first hundred years of stocking, the location and number of fish intro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oystering Machinery
In oyster hatcheries fewer machines are needed but the most important one is the nursery tank system that keeps the oyster larvae alive. The nursery tank system was developed in Florida. Boats and small rafts were also used to gather the oysters in the deep if they cannot reach by bare foot. The rafts and boats were made in Italy. Also while they remove the oysters they use a small knife or a stone to weaken the oyster from the rocks. The knives are from China. A filter is also a main one to keep the hatchery water clean and the same water level. Such filters are made in Japan. When the oysters need to be carried by hand the workers used Hessian bags made in the United Kingdom. Racks are used often to dry out the bacteria on the oysters. This are also from the United States of America The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turtle
Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked turtles), which differ in the way the head retracts. There are 360 living and recently extinct species of turtles, including land-dwelling tortoises and freshwater terrapins. They are found on most continents, some islands and, in the case of sea turtles, much of the ocean. Like other amniotes (reptiles, birds, and mammals) they breathe air and do not lay eggs underwater, although many species live in or around water. Turtle shells are made mostly of bone; the upper part is the domed carapace, while the underside is the flatter plastron or belly-plate. Its outer surface is covered in scales made of keratin, the material of hair, horns, and claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poultry Farming
Poultry farming is the form of animal husbandry which raises domesticated birds such as chickens, ducks, turkeys and geese to produce meat or eggs for food. Poultry – mostly chickens – are farmed in great numbers. More than 60 billion chickens are killed for consumption annually. Chickens raised for eggs are known as layers, while chickens raised for meat are called broilers. In the United States, the national organization overseeing poultry production is the Food and Drug Administration (FDA). In the UK, the national organisation is the Department for Environment, Food and Rural Affairs (Defra). Intensive and alternative According to the World Watch Institute, 74 percent of the world's poultry meat, and 68 percent of eggs are produced intensively.''State of the World 2006'' World "atch Institute, p. 26 One alternative to intensive poultry farming is free-range farming using lower stocking densities. Poultry producers routinely use nationally approved medications, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Threatened Species
Threatened species are any species (including animals, plants and fungi) which are vulnerable to endangerment in the near future. Species that are threatened are sometimes characterised by the population dynamics measure of '' critical depensation'', a mathematical measure of biomass related to population growth rate. This quantitative metric is one method of evaluating the degree of endangerment. IUCN definition The International Union for Conservation of Nature (IUCN) is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories, depending on the degree to which they are threatened: *Vulnerable species * Endangered species * Critically endangered species Less-than-threatened categories are near threatened, least concern, and the no longer assigned category of conservation dependent. Species which have not been evaluated (NE), or do not have sufficient data ( data deficient) also are not consid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inbreeding Depression
Inbreeding depression is the reduced biological fitness which has the potential to result from inbreeding (the breeding of related individuals). Biological fitness refers to an organism's ability to survive and perpetuate its genetic material. Inbreeding depression is often the result of a population bottleneck. In general, the higher the genetic variation or gene pool within a breeding population, the less likely it is to suffer from inbreeding depression, though inbreeding and outbreeding depression can simultaneously occur. Inbreeding depression seems to be present in most groups of organisms, but varies across mating systems. Hermaphroditic species often exhibit lower degrees of inbreeding depression than outcrossing species, as repeated generations of selfing is thought to purge deleterious alleles from populations. For example, the outcrossing nematode (roundworm) ''Caenorhabditis remanei'' has been demonstrated to suffer severely from inbreeding depression, unlike i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Viable Population
Minimum viable population (MVP) is a lower bound on the population of a species, such that it can survive in the wild. This term is commonly used in the fields of biology, ecology, and conservation biology. MVP refers to the smallest possible size at which a biological population can exist without facing extinction from natural disasters or demographic, environmental, or genetic stochasticity. The term "population" is defined as a group of interbreeding individuals in similar geographic area that undergo negligible gene flow with other groups of the species. Typically, MVP is used to refer to a wild population, but can also be used for ex-situ conservation (Zoo populations). Estimation There is no unique definition of what is a sufficient population for the continuation of a species, because whether a species survives will depend to some extent on random events. Thus any calculation of a minimum viable population (MVP) will depend on the population projection model used. A set o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered Species
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 assessing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Insemination
Insemination is the introduction of sperm into a female’s reproductive system for the purpose of impregnating, also called fertilizing, the female for sexual reproduction. The sperm is introduced into the uterus of a mammal or the oviduct of an oviparous (egg-laying) animal. In mammals, insemination normally occurs during sexual intercourse or copulation, but insemination can take place in other ways, such as by artificial insemination. In humans, the act and form of insemination has legal, moral and interpersonal implications. However, whether insemination takes place naturally or by artificial means, the pregnancy and the progress of it will be the same. Insemination may be called ''in vivo'' fertilisation (from ''in vivo'' meaning "within the living") because an egg is fertilized inside the body, this is in contrast with in vitro fertilisation (IVF). In plants, the fertilization process is referred to as pollination. It is the process of transfer of pollen grains from one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turkeys
The turkey is a large bird in the genus ''Meleagris'', native to North America. There are two extant turkey species: the wild turkey (''Meleagris gallopavo'') of eastern and central North America and the ocellated turkey (''Meleagris ocellata'') of the Yucatán Peninsula in Mexico. Males of both turkey species have a distinctive fleshy wattle, called a snood, that hangs from the top of the beak. They are among the largest birds in their ranges. As with many large ground-feeding birds (order Galliformes), the male is bigger and much more colorful than the female. Native to North America, the wild species was bred as domesticated turkey by indigenous peoples. It was this domesticated turkey that later reached Eurasia, during the Columbian exchange. In English, "turkey" probably got its name from the domesticated variety being imported to Britain in ships coming from the Turkish Levant via Spain. The British at the time therefore associated the bird with the country Turkey an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chicken
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult male bird, and a younger male may be called a cockerel. A male that has been castrated is a capon. An adult female bird is called a hen and a sexually immature female is called a pullet. Humans now keep chickens primarily as a source of food (consuming both their meat and eggs) and as pets. Traditionally they were also bred for cockfighting, which is still practiced in some places. Chickens are one of the most common and widespread domestic animals, with a total population of 23.7 billion , up from more than 19 billion in 2011. There are more chickens in the world than any other bird. There are numerous cultural references to chickens – in myth, folklore and religion, and in language and literature. Genetic studies have poi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Princeton University
Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the nine colonial colleges chartered before the American Revolution. It is one of the highest-ranked universities in the world. The institution moved to Newark in 1747, and then to the current site nine years later. It officially became a university in 1896 and was subsequently renamed Princeton University. It is a member of the Ivy League. The university is governed by the Trustees of Princeton University and has an endowment of $37.7 billion, the largest endowment per student in the United States. Princeton provides undergraduate and graduate instruction in the humanities, social sciences, natural sciences, and engineering to approximately 8,500 students on its main campus. It offers postgraduate degrees through the Princeton ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
