|
Ryūkyū Spiny Rat
The Ryukyu spiny rat (''Tokudaia osimensis'') is a species of rodent in the family Muridae. Endemic to Amami Ōshima island in the Amami Islands of the Ryukyu archipelago of Japan, its natural habitat is subtropical moist broadleaf forest. The karyotype has an odd diploid number, 2n = 25. Like its relative '' T. tokunoshimensis'', it has lost its Y chromosome and ''SRY'' gene. The species is threatened by habitat destruction and fragmentation, predation by feral cats and dogs and introduced mongooses, and competition with introduced black rats. See also * '' Ellobius lutescens'' * ''Ellobius tancrei The Zaisan mole vole (''Ellobius tancrei''), or eastern mole vole, is a species of rodent in the family Cricetidae. It is found in central Asia. Description The Zaisan mole vole is highly adapted to life underground. It grows to a head and body ...'' References Y-chromosome - Will it or will it not, hold on? Rats of Asia Endemic mammals of Japan Endemic fauna of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal species are rodents. They are native to all major land masses except for Antarctica, and several oceanic islands, though they have subsequently been introduced to most of these land masses by human activity. Rodents are extremely diverse in their ecology and lifestyles and can be found in almost every terrestrial habitat, including human-made environments. Species can be arboreal, fossorial (burrowing), saltatorial/ricochetal (leaping on their hind legs), or semiaquatic. However, all rodents share several morphological features, including having only a single upper and lower pair of ever-growing incisors. Well-known rodents include Mouse, mice, rats, squirrels, prairie dogs, porcupines, beavers, Cavia, guinea pigs, and hamsters. Once included wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat Fragmentation
Habitat fragmentation describes the emergence of discontinuities (fragmentation) in an organism's preferred environment (habitat), causing population fragmentation and ecosystem decay. Causes of habitat fragmentation include geological processes that slowly alter the layout of the physical environment (suspected of being one of the major causes of speciation), and human activity such as land conversion, which can alter the environment much faster and causes the extinction of many species. More specifically, habitat fragmentation is a process by which large and contiguous habitats get divided into smaller, isolated patches of habitats. Definition The term habitat fragmentation includes five discrete phenomena: * Reduction in the total area of the habitat * Decrease of the interior: edge ratio * Isolation of one habitat fragment from other areas of habitat * Breaking up of one patch of habitat into several smaller patches * Decrease in the average size of each patch of habit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokudaia
''Tokudaia'' is a genus of murine rodent native to Japan. Known as Ryūkyū spiny rats or spinous country-rats, population groups exist on several non-contiguous islands. Despite differences in name and appearance, they are the closest living relatives of the Eurasian field mouse (''Apodemus''). Of the three species, both ''T. osimensis'' and ''T. tokunoshimensis'' have lost their Y chromosome and ''SRY'' gene; the sex chromosomes of ''T. muenninki'', on the other hand, are abnormally large. Named species are: * Muennink's spiny rat, ''Tokudaia muenninki'' * Ryukyu spiny rat, ''Tokudaia osimensis'' * Tokunoshima spiny rat, ''Tokudaia tokunoshimensis'' At least ''Tokudaia osimensis'' may be a cryptic species complex. See also * ''Ellobius ''Ellobius'' is a genus of rodents in the family Cricetidae. It contains two ('' E. talpinus'' and '' E. tancrei'') of the handful of examples of mammal species that have lost the Y chromosome The Y chromosome is one of two sex chrom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered Fauna Of Asia
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, invasive species, and climate change. 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 consider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of The Ryukyu Islands
Endemism is the state of a species being found only 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 also be referred to as an ''endemism'' or, in scientific literature, as an ''endemite''. Similarly, many species found in the Western ghats of India are examples of endemism. Endemism is an important concept in conservation biology for measuring biodiversity in a particular place and evaluating the risk of extinction for species. Endemism is also of interest in evolutionary biology, because it provides clues about how changes in the environment cause species to undergo range shifts (potentially expanding their range into a larger area or becomin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rats Of Asia
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' (pack rats), ''Bandicota'' (bandicoot rats) and ''Dipodomys'' (kangaroo rats). Rats are typically distinguished from mouse, mice by their size. Usually the common name of a large muroid rodent will include the word "rat", while a smaller muroid's name will include "mouse". The common terms ''rat'' and ''mouse'' are not Taxonomy (biology), taxonomically specific. There are 56 known species of rats in the world. Species and description The best-known rat species are the black rat (''Rattus rattus'') and the brown rat (''Rattus norvegicus''). This group, generally known as the Old World rats or true rats, originated in Asia. Rats are bigger than most Old World mouse, mice, which are their relatives, but seldom weigh over in the wild. The term ''rat'' is also used in the names ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellobius Tancrei
The Zaisan mole vole (''Ellobius tancrei''), or eastern mole vole, is a species of rodent in the family Cricetidae. It is found in central Asia. Description The Zaisan mole vole is highly adapted to life underground. It grows to a head and body length of with a short tail long and weighs between . The coat is dense, soft and velvety. The face and the crown of the head are dark brown and the external ears are reduced to a fleshy ridge. The incisors are pure white, straight and long and project forward in front of the snout. The dorsal surface of the body varies in colour from sandy brown to dark greyish brown and the underparts vary from white to greyish brown. The tail is sandy brown and is tipped with a tuft of greyish-white hair. The hands and feet are broad, have small claws and are covered with white hairs. Chromosomes The karyotype is variable, with 2n = 32-54. The Y chromosome has been lost, similar to the case of '' E. lutescens''; however, unlike in ''E. lutescens'', b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellobius Lutescens
The Transcaucasian mole vole (''Bramus lutescens'') is a species of rodent in the family Cricetidae. It is found in Armenia, Azerbaijan, Georgia, Iran, and Turkey. Reproduction Transcaucasian mole vole, they reproduce during the months of April to October, breeding in march-April and October-November, in which the females would gestate their young for 26 days( almost a month). After birth the pups of the Transcaucasian mole vole, they would stay with their mother for about two months. During the pups 1-4 week of their life it would be just feeding with their mother, and developing their motor functions and being able to be weaned off milk and be able to eat solid food. The final and fifth week the pups would be able to be weaned off the milk and eat vegetables by themselves and be able to walk by themselves without difficulty. Chromosomes The karyotype has a low, odd, diploid number, 2n = 17,X. Transcaucasian mole voles have no ''SRY'' gene or Y chromosome; both sexes have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black Rat
The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is now found worldwide. The black rat is black to light brown in colour with a lighter underside. It is a generalist omnivore and a serious Pest (organism), pest to farmers because it feeds on a wide range of agricultural crops. It is sometimes kept as a pet. In parts of India, it is considered sacred and respected in the Karni Mata Temple in Deshnoke. Taxonomy ''Mus rattus'' was the scientific name proposed by Carl Linnaeus in 1758 for the black rat. Three subspecies were once recognized, but today are considered invalid and are now known to be actually Morph (zoology), color morphs: *''Rattus rattus rattus'' – roof rat *''Rattus rattus alexandrinus'' – Alexandrine rat *''Rattus rattus frugivorus'' – fruit rat Characteristics A ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpestes Auropunctatus
The small Indian mongoose (''Urva auropunctata'') is a mongoose species native to Iraq and northern India; it has also been introduced to several Caribbean and Pacific islands. Taxonomy ''Mangusta auropunctata'' was the scientific name proposed by Brian Houghton Hodgson in 1836 for a mongoose specimen collected in central Nepal. In the 19th and 20th centuries, several zoological specimens were described: *''Mangusta pallipes'' proposed by Edward Blyth in 1845 was based on mongooses observed in Kandahar, Afghanistan. *''Herpestes palustris'' proposed by R. K. Ghose in 1965 was an adult male mongoose collected in a swamp on the eastern fringe of Kolkata, India. The small Indian mongoose was later classified in the genus ''Herpestes''; all Asian mongooses are now classified the genus '' Urva''. The small Indian mongoose was once considered a subspecies of the Javan mongoose (''H. javanicus''). Genetic analysis of hair and tissue samples from 18 small Indian and Javan mongooses reve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Introduced Species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are ''new'' biota to their environment in terms of established biological network (e.g. food web) relationships. Neobiota can further be divided into neozoa (also: neozoons, sing. neozoon, i.e. animals) and ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
