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Freshwater Crab
Around 1,300 species of freshwater crabs are distributed throughout the tropics and subtropics, divided among eight families. They show direct development and maternal care of a small number of offspring, in contrast to marine crabs, which release thousands of planktonic larvae. This limits the dispersal abilities of freshwater crabs, so they tend to be endemic to small areas. As a result, a large proportion are threatened with extinction. Systematics More than 1,300 described species of freshwater crabs are known, out of a total of 6,700 species of crabs across all environments. The total number of species of freshwater crabs, including undescribed species, is thought to be up to 65% higher, potentially up to 2,155 species, although most of the additional species are currently unknown to science. They belong to eight families, each with a limited distribution, although various crabs from other families are also able to tolerate freshwater conditions ( euryhaline) or are second ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamon Ibericus (1)
''Potamon'' is a genus of freshwater or semiterrestrial crabs mainly found from Southern Europe through the Middle East, and as far east as north-western India. The only exception is the North African ''P. algeriense'', which also is the only potamid of mainland Africa. Twenty species are currently recognised:. These crabs are omnivores that have a broad ecological tolerance. The adult Potaman reach up to 50 mm in size during their 10-12 year life span. *'' Potamon algeriense'' *''Potamon bileki'' *''Potamon bilobatum'' *''Potamon fluviatile'' *''Potamon gedrosianum'' *''Potamon hueceste'' *'' Potamon ibericum'' *''Potamon magnum'' *'' Potamon mesopotamicum'' *''Potamon monticola'' *''Potamon pelops'' *''Potamon persicum'' *'' Potamon potamios'' *''Potamon rhodium'' *''Potamon ruttneri'' *''Potamon setigerum'' *'' Potamon strouhali'' *'' Potamon transcaspicum'' *'' Potamon ilam'' *'' Potamon elbursi'' Many other taxa from Indochina Mainland Sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern Subregion#Americas, subregion of a single continent called Americas, America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territory, dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one administrative division, internal territory: French Guiana. In addition, the ABC islands (Leeward Antilles), ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Asce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gecarcinucidae
The Gecarcinucidae are a family of true freshwater crabs. The family Parathelphusidae is now demoted to the rank of subfamily, as the Parathelphusinae, within the Gecarcinucidae. "Family" Parathelphusidae is now considered as a junior synonym. Taxonomy The Gecarcinucidae are thought to have originated in the Indian subcontinent when it was an island continent in the Paleogene, despite not being of ancient Gondwanan origins themselves (unlike other lineages that are thought to have originated in Insular India). Divergence estimates indicate that the Gecarcinucidae originate from Southeast Asian ancestors that dispersed to India during the middle Eocene, before India collided with Asia. This is thought to have occurred due to India drifting close enough to Southeast Asia to allow for biotic exchange between both regions. As the Gecarcinucidae are a freshwater group that could not disperse via marine habitats, this indicates that temporary land bridges may have formed in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gecarcinucoidea
Gecarcinucoidea is a superfamily of freshwater crabs. Its members have been grouped into families in various ways, with some authors recognizing families such as "Deckeniidae", "Sundathelphusidae", and "Parathelphusidae", but now only the family Gecarcinucidae The Gecarcinucidae are a family of true freshwater crabs. The family Parathelphusidae is now demoted to the rank of subfamily, as the Parathelphusinae, within the Gecarcinucidae. "Family" Parathelphusidae is now considered as a junior synonym. ... is currently recognized. References Crabs Taxa named by Mary J. Rathbun Arthropod superfamilies {{crab-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Platythelphusidae
''Platythelphusa'' is a genus of freshwater crabs endemic to Lake Tanganyika. It has been placed in a number of families, including a monotypic family, Platythelphusidae, as well as Potamidae and its current position in the Potamonautidae, and has also been treated as a subgenus of '' Potamonautes''. It forms a monophyletic group, possibly nested within the genus ''Potamonautes'', which would therefore be paraphyletic. The genus is the only evolutionary radiation of crabs to have occurred in a freshwater lake, and it occurred recently, probably since the Pliocene. This parallels the better known radiation of cichlid fishes in Lake Tanganyika. Only one other species of freshwater crab is found in Lake Tanganyika, ''Potamonautes platynotus''. Taxonomic history The first freshwater crab to be described from Lake Tanganyika, by Alphonse Milne-Edwards in 1887, was considered so distinct from the other crabs known up to that time that it was placed in a new genus, as ''Platythelphusa a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seychelles
Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, Victoria, is east of mainland Africa. Nearby island countries and territories include the Comoros, Madagascar, Mauritius, and the French overseas departments of Mayotte and Réunion to the south; and Maldives and the Chagos Archipelago (administered by the United Kingdom as the British Indian Ocean Territory) to the east. It is the least populated sovereign African country, with an estimated 2020 population of 98,462. Seychelles was uninhabited prior to being encountered by Europeans in the 16th century. It faced competing French and British interests until coming under full British control in the late 18th century. Since proclaiming independence from the United Kingdom in 1976, it has developed from a largely agricultural societ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
East Africa
East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historical Omani Empire and colonial territories of the British East Africa Protectorate and German East Africa, the term ''East Africa'' is often (especially in the English language) used to specifically refer to the area now comprising the three countries of Kenya, Tanzania, and Uganda. However, this has never been the convention in many other languages, where the term generally had a wider, strictly geographic context and therefore typically included Djibouti, Eritrea, Ethiopia, and Somalia.Somaliland is not included in the United Nations geoscheme, as it is internationally recognized as a part of Somalia. *Tanzania, Kenya, Uganda, Rwanda, Burundi, Democratic Republic of Congo and South Sudan are members of the East African Community. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deckeniidae
Potamonautidae is a family of freshwater crabs endemic to Africa, including the islands of Madagascar, the Seychelles, Zanzibar, Mafia, Pemba, Bioko, São Tomé, Príncipe and Sherbro Island. It comprises 18 extant genera and 138 extant species. Fossil remains dating from the Late Miocene period have been attributed to the family Potamonautidae. It comprises the following subfamilies and genera: ; Deckeniinae Ortmann, 1897 *'' Deckenia'' Hilgendorf, 1869 *'' Seychellum'' Ng, Števčić & Pretzmann, 1995 ; Hydrothelphusinae Bott, 1955 *'' Afrithelphusa'' Bott, 1969 *'' Boreas'' Cumberlidge & von Sternberg, 2002 *'' Globonautes'' Bott, 1959 *'' Hydrothelphusa'' A. Milne-Edwards, 1872 *'' Louisea'' Cumberlidge, 1994 *'' Madagapotamon'' Bott, 1965 *'' Malagasya'' Cumberlidge & von Sternberg, 2002 *'' Marojejy'' Cumberlidge, Boyko & Harvey, 2002 *'' Skelosophusa'' Ng & Takeda, 1994 ; Potamonautinae Bott, 1970 *'' Erimetopus'' Rathbun, 1894 *''Foza'' Dai & Bo, 1994 *'' Liberonautes'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa across the Mozambique Channel. At Madagascar is the world's List of island countries, second-largest island country, after Indonesia. The nation is home to around 30 million inhabitants and consists of the island of Geography of Madagascar, Madagascar (the List of islands by area, fourth-largest island in the world), along with numerous smaller peripheral islands. Following the prehistoric breakup of the supercontinent Gondwana, Madagascar split from the Indian subcontinent around 90 million years ago, allowing native plants and animals to evolve in relative isolation. Consequently, Madagascar is a biodiversity hotspot; over 90% of wildlife of Madagascar, its wildlife is endemic. Human settlement of Madagascar occurred during or befo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With billion people as of , it accounts for about of the world's human population. Africa's population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Despite a wide range of natural resources, Africa is the least wealthy continent per capita and second-least wealthy by total wealth, behind Oceania. Scholars have attributed this to different factors including geography, climate, tribalism, Scramble for Africa, colonialism, the Cold War, neocolonialism, lack of democracy, and corruption. Despite this low concentration of wealth, recent economic expansion and the large and young ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamonautidae
Potamonautidae is a family of freshwater crabs endemic to Africa, including the islands of Madagascar, the Seychelles, Zanzibar, Mafia, Pemba, Bioko, São Tomé, Príncipe and Sherbro Island. It comprises 18 extant genera and 138 extant species. Fossil remains dating from the Late Miocene period have been attributed to the family Potamonautidae. It comprises the following subfamilies and genera: ; Deckeniinae Ortmann, 1897 *'' Deckenia'' Hilgendorf, 1869 *''Seychellum'' Ng, Števčić & Pretzmann, 1995 ; Hydrothelphusinae Bott, 1955 *''Afrithelphusa'' Bott, 1969 *'' Boreas'' Cumberlidge & von Sternberg, 2002 *''Globonautes'' Bott, 1959 *'' Hydrothelphusa'' A. Milne-Edwards, 1872 *''Louisea'' Cumberlidge, 1994 *'' Madagapotamon'' Bott, 1965 *'' Malagasya'' Cumberlidge & von Sternberg, 2002 *''Marojejy'' Cumberlidge, Boyko & Harvey, 2002 *'' Skelosophusa'' Ng & Takeda, 1994 ; Potamonautinae Bott, 1970 *'' Erimetopus'' Rathbun, 1894 *'' Foza'' Dai & Bo, 1994 *'' Liberonautes'' Bott ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area of , about 30% of Earth's total land area and 8.7% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Its 4.7 billion people constitute roughly 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, ling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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