Parathelphusidae is a family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 of freshwater crab

Freshwater crab

There are around 1,300 species of freshwater crabs, 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...

s mainly in Southeast Asia

Southeast Asia

Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

. Their closest living relatives are the Gecarcinucidae

Gecarcinucidae

Gecarcinucidae is a family of freshwater crabs. Some scientists also include the genera placed in the family Parathelphusidae in a larger Gecarcinucidae....

.

The Parathelphusidae inhabit river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s, lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s and rice paddies

Paddy field

A paddy field is a flooded parcel of arable land used for growing rice and other semiaquatic crops. Paddy fields are a typical feature of rice farming in east, south and southeast Asia. Paddies can be built into steep hillsides as terraces and adjacent to depressed or steeply sloped features such...

. Some species, for example from the genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Somanniathelphusa

Somanniathelphusa

Somanniathelphusa is a genus of freshwater crabs found in southeast China, Taiwan, and southeast Asia. It includes the following species:*Somanniothelphusa amoyensis Naiyanetr & Dai, 1997*Somanniothelphusa araeochela Naiyanetr & Dai, 1997...

, are locally important as food, particularly in Thailand

Thailand

Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...

 where they are an important ingredient in som tam

Som tam

Som tam or som tum also known as tam bak hung is a spicy salad, the standard form of which is made from shredded unripened papaya. Som tam is similar to the Laotian dish tam mak hung and the Cambodian dish bok l'hong...

. Some others are very rare and close to extinction

Extinction

In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...

.

Genera in this family are:

• Adelaena
• Arachnothelphusa
• Austrothelphusa
  Austrothelphusa
  Austrothelphusa is a genus of freshwater crab endemic to Australia, comprising the following species:*Austrothelphusa agassizi *Austrothelphusa angustifrons Austrothelphusa is a genus of freshwater crab endemic to Australia, comprising the following species:*Austrothelphusa agassizi (Rathbun,...
  
  
• Bakousa
• Bassiathelphusa
• Ceylonthelphusa
  Ceylonthelphusa
  Ceylonthelphusa is a genus of freshwater crabs endemic to Sri Lanka, where they live in moist lowland forests, swamps and rivers. Many of the species are on the IUCN Red List of threatened species, with the greatest risk factor begin habitat loss...
  
  
• Clinothelphusa
  Clinothelphusa
  Clinothelphusa kakoota is a species of crab in the family Parathelphusidae, which is endemic to Sri Lanka. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical swamps, and rivers. It is threatened by habitat loss, and is listed as a critically endangered...
  
  
• Coccusa
• Currothelphusa
• Esanthelphusa
• Geelvinkia
• Geithusa
• Heterothelphusa
• Holthuisana
• Irmengardia
• Mahatha
  Mahatha
  Mahatha is a genus of freshwater crabs endemic to Sri Lanka. Four of the six species are critically endangered due to habitat loss, and two are listed as Least Concern on the IUCN Red List.-Mahatha adonis:...
  
  
• Mainitia
• Mekongthelphusa
• Migmathelphusa
• Nautilothelphusa
• Niasathelphusa
• Oziotelphusa
  Oziotelphusa
  Oziotelphusa is a genus of freshwater crabs in the family Parathelphusidae. Its members are found in Sri Lanka and southern India ....
  
  
• Parathelphusa
• Pastilla
• Perbrinckia
  Perbrinckia
  Perbrinckia is a genus of freshwater crabs endemic to Sri Lanka. Its natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical swamps, and rivers...
  
  
• Perithelphusa
• Rouxana
• Salangathelphusa
• Sartoriana
• Sayamia
• Sendleria
• Siamthelphusa
• Somanniathelphusa
  Somanniathelphusa
  Somanniathelphusa is a genus of freshwater crabs found in southeast China, Taiwan, and southeast Asia. It includes the following species:*Somanniothelphusa amoyensis Naiyanetr & Dai, 1997*Somanniothelphusa araeochela Naiyanetr & Dai, 1997...
  
  
• Spiralothelphusa
  Spiralothelphusa
  Spiralothelphusa is a genus of freshwater crabs in the family Parathelphusidae. It contains the following species, all of which are included on the IUCN Red List :...
  
  
• Stygothelphusa
• Sundathelphusa
• Syntripsa
• Terrathelphusa
• Thelphusula
• Torhusa