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Afrithelphusa
''Afrithelphusa'' is a genus of freshwater crabs in the family Deckeniidae. It contains four species, all of which were formerly listed as critically endangered by the International Union for Conservation of Nature (IUCN). They are all endemic to the Upper Guinean forests of Guinea and Sierra Leone. ''Afrithelphusa afzelii'' ''Afrithelphusa afzelii'' (Colosi, 1924) is known from two specimens collected before 1800 from a single, unknown locality in Sierra Leone. It is considered IUCN Red List, possibly extinct. ''Afrithelphusa gerhildae'' ''Afrithelphusa gerhildae'' (Bott, 1969) is known from three specimens collected in 1957 in Kindia, Guinea. Although population sizes are not known, the expansion of slash and burn agriculture and deforestation are likely to have caused it to decline. The lack of information about this species has led to its reappraisal as Data Deficient. ''Afrithelphusa leonensis'' ''Afrithelphusa leonensis'' (Cumberlidge, 1987) is known from three specimens ... [...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] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slash And Burn
Slash-and-burn agriculture is a farming method that involves the cutting and burning of plants in a forest or woodland to create a field called a swidden. The method begins by cutting down the trees and woody plants in an area. The downed vegetation, or "slash", is then left to dry, usually right before the rainiest part of the year. Then, the biomass is burned, resulting in a nutrient-rich layer of ash which makes the soil fertile, as well as temporarily eliminating weed and pest species. After about three to five years, the plot's productivity decreases due to depletion of nutrients along with weed and pest invasion, causing the farmers to abandon the field and move to a new area. The time it takes for a swidden to recover depends on the location and can be as little as five years to more than twenty years, after which the plot can be slashed and burned again, repeating the cycle. In Bangladesh and India, the practice is known as jhum or jhoom. Slash-and-burn is a type of shif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater Crustaceans Of Africa
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non- salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranea (geography), subterranean subterranean river, rivers and underground lake, lakes. Fresh water is the Water resources, water resource that is of the most and immediate use to humans. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potamoidea
Potamoidea is a superfamily of freshwater crabs, comprising the two families Potamidae Potamidae is a family (biology), family of freshwater crabs. It includes more than 650 species and nearly 100 genera, which are placed into two subfamilies: Potaminae and Potamiscinae. Subfamily Potaminae The Potaminae Ortmann, 1896 are distrib ... and Potamonautidae. Two previously recognised families, Deckeniidae and Platythelphusidae, are now treated as parts of the family Potamonautidae. References Crabs Arthropod superfamilies {{crab-stub ... [...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 the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Douala
University of Douala, or Université de Douala (UDla), is located in Douala in Cameroon. The University of Douala is one of the eight public universities of Cameroon. History The current structure of the University of Douala was established in 1993. The university incorporated the previous University Centre (Centre universitaire established in 1977) which was made of the ''Ecole Supérieure des Sciences Economiques et Commerciales'' (ESSEC established in 1977) and the ''Ecole Normale d'Enseignement Technique'' (ENSET established in 1979) and which was transformed into a university in 1992. The university has around 40.000 students, 600 teachers and around 600 administrators and collaborators. The University of Douala has six locations in different neighborhoods of the city of Douala: * Campus Bassa "Cité SIC" where the main campus is located (ecole superieures des sciences economiques et commerciales, faculté des sciences juridiques et commerciales, faculté des sciences ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre A
Pierre is a masculine given name. It is a French form of the name Peter. Pierre originally meant "rock" or "stone" in French (derived from the Greek word πέτρος (''petros'') meaning "stone, rock", via Latin "petra"). It is a translation of Aramaic כיפא (''Kefa),'' the nickname Jesus gave to apostle Simon Bar-Jona, referred in English as Saint Peter. Pierre is also found as a surname. People with the given name * Abbé Pierre, Henri Marie Joseph Grouès (1912–2007), French Catholic priest who founded the Emmaus Movement * Monsieur Pierre, Pierre Jean Philippe Zurcher-Margolle (c. 1890–1963), French ballroom dancer and dance teacher * Pierre (footballer), Lucas Pierre Santos Oliveira (born 1982), Brazilian footballer * Pierre, Baron of Beauvau (c. 1380–1453) * Pierre, Duke of Penthièvre (1845–1919) * Pierre, marquis de Fayet (died 1737), French naval commander and Governor General of Saint-Domingue * Prince Pierre, Duke of Valentinois (1895–1964), father ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moyamba District
Moyamba District is a district in the Southern Province of Sierra Leone, with a population of 318,064 in the 2015 census. Its capital and largest city is Moyamba. The other major towns include Njala, Rotifunk and Shenge. The district is the largest in the Southern Province by geographical area, occupying a total area of and comprises fourteen chiefdoms. Moyamba District borders the Atlantic Ocean in the west, Port Loko District and Tonkolili District to the north, Bo District to the east and Bonthe District to the south. The main economic activities include mining (rutile and bauxite), fishing, rice growing and oil palm plantations. Moyamba District is one of the most ethnically diverse Districts in Sierra Leone. The Mende people are the largest ethnic group in Moyamba District; However, there is a large population of ethnic minority groups in the district that make up closer to 50% of the District population, including the Temne people, Fulani, Sherbro, Kissi, Mandingo, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Deficient
A data deficient (DD) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as offering insufficient information for a proper assessment of conservation status to be made. This does not necessarily indicate that the species has not been extensively studied; but it does indicate that little or no information is available on the abundance and distribution of the species. The IUCN recommends that care be taken to avoid classing species as "data deficient" when the absence of records may indicate dangerously low abundance: "If the range of a taxon is suspected to be relatively circumscribed, if a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified""The Categories," in IUCN (1983). (see also precautionary principle). See also * IUCN Red List data deficient species * List of data deficient amphibians * IUCN Red List data deficient species (Annelida) * List of data deficien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deforestation
Deforestation or forest clearance is the removal of a forest or stand of trees from land that is then converted to non-forest use. Deforestation can involve conversion of forest land to farms, ranches, or urban use. The most concentrated deforestation occurs in tropical rainforests. About 31% of Earth's land surface is covered by forests at present. This is one-third less than the forest cover before the expansion of agriculture, a half of that loss occurring in the last century. Between 15 million to 18 million hectares of forest, an area the size of Bangladesh, are destroyed every year. On average 2,400 trees are cut down each minute. The Food and Agriculture Organization of the United Nations defines deforestation as the conversion of forest to other land uses (regardless of whether it is human-induced). "Deforestation" and "forest area net change" are not the same: the latter is the sum of all forest losses (deforestation) and all forest gains (forest expansion) in a gi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
