''Afrithelphusa'' is a

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 com ...

freshwater 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 ...

crab Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all the ...

s in the family

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. ...

. It contains four

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, all of which were formerly listed as critically endangered by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN). They are all

endemic Endemism is the state of a species being found 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 elsew ...

to the

Upper Guinean forests The Upper Guinean forests is a tropical seasonal forest region of West Africa. The Upper Guinean forests extend from Guinea and Sierra Leone in the west through Liberia, Côte d'Ivoire and Ghana to Togo in the east, and a few hundred kilometers inl ...

Guinea Guinea ( ),, fuf, 𞤘𞤭𞤲𞤫, italic=no, Gine, wo, Gine, nqo, ߖߌ߬ߣߍ߫, bm, Gine officially the Republic of Guinea (french: République de Guinée), is a coastal country in West Africa. It borders the Atlantic Ocean to the we ...

and

Sierra Leone Sierra Leone,)]. officially the Republic of Sierra Leone, is a country on the southwest coast of West Africa. It is bordered by Liberia to the southeast and Guinea surrounds the northern half of the nation. Covering a total area of , Sierra ...

''Afrithelphusa afzelii''

''Afrithelphusa afzelii'' (Colosi, 1924) is known from two specimens collected before 1800 from a single, unknown locality in

. It is considered IUCN Red List, possibly extinct.

''Afrithelphusa gerhildae''

''Afrithelphusa gerhildae'' (Bott, 1969) is known from three specimens collected in 1957 in

Kindia Kindia ( N’ko: ߞߌ߲ߘߌߦߊ߫) is the fourth largest city in Guinea, lying about 85 miles northeast of the nation's capital, Conakry. Its estimated population in 2008 was 181,126. Kindia serves as the capital and largest city of Kindia Prefe ...

. Although population sizes are not known, the expansion of

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 vegeta ...

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people to ...

and

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 d ...

are likely to have caused it to decline. The lack of information about this species has led to its reappraisal as

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 necessaril ...

''Afrithelphusa leonensis''

''Afrithelphusa leonensis'' (Cumberlidge, 1987) is known from three specimens collected in 1955 at one locality in

. It is considered critically endangered. The crab is among the 25 "lost species" that will be surveyed in the "Search for Lost Species" program by the non-profit organization Global Wildlife Conservation (GWC). In 2021, the species was rediscovered in

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 la ...

by Pierre A. Mvogo Ndongo, a researcher from the

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 i ...

''Afrithelphusa monodosa''

''Afrithelphusa monodosa'' (Bott, 1959), the ''purple marsh crab'', is the best known of the four species, new populations having been discovered since 1996. Despite this, fewer than 20 specimens have been collected, and the total population is likely to be less than 2,500. This crab is now listed as

endangered 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 inva ...

References

External links

* {{Taxonbar, from=Q18581091 Potamoidea Freshwater crustaceans of Africa Crustacean genera Taxonomy articles created by Polbot