Added September 14 2003. Last updated 31 October 2010 with updated introduction and link to magazine articles.

Trionychidae

Soft-Shelled Turtles

A very distinctive group of chelonians, distinguished principally by their flat, disc-shaped and non-rigid shells. This lack of the normal chelonian defence goes some way to explaining the prickly temperament of most if not all of the species in this family: for this reason they do not make suitable pets for a lot of people.

Another distinguishing feature is the elongated "snout" found in many if not all species. This aids breathing while the creature is submerged (the tip of the snout normally protruding just above the surface): in keeping with their highly aquatic lifestyle, the species can also breathe via both skin and pharynx while submerged. In some parts of the world they are the largest freshwater turtles. The name of the family derives from the three claws found on each flipper.

Distribution is uneven, with most of the species in North America and South Asia and the remaining few in Africa. There are two subfamilies. Recently the large genus Trionyx has been broken up into a number of smaller genera.

For French speakers, issue 18 of Chéloniens magazine is dedicated to the softshells and its articles cover a number of species from North America and Asia.

Subfamily Cyclanorbinae (Flapped Soft-Shelled Terrapins)

Genus Common Name No. of species Location Notes
Cyclanorbis Nubian and Senegal Soft-Shelled Turtles 2 Africa  
Cycloderma African Flap-Shelled Turtles 2 Africa  
Lissemys Indian and Burmese Flap-Shelled Turtles 2 Indian subcontinent, Sri Lanka and Burma  

Subfamily Trionychinae

Genus Common Name No. of species Location Notes
Amyda   2 SE Asia   
Apalone   3 North America (USA, Canada and Mexico)  
Aspideretes   4 Indian subcontinent (India, Pakistan, Bangladesh and Nepal)  
Chitra Narrow-Headed Soft-Shelled Turtles 2 India, Pakistan, Nepal, Bangladesh, Thailand, Malaysia, Indonesia (Java and Sumatra)  
Dogonia Malayan Soft-Shelled Turtle 1 S Burma, Thailand, W Malaysia, Singapore, Philippines and Indonesia (inc. Java, Borneo and Sumatra)  
Nilssonia Burmese Soft-Shelled Turtle 1 Burma  
Palea Wattle-Necked Soft-Shelled Turtle  1 China and Vietnam; introduced into Hawaii and Mauritius  
Pelochelys Asian Giant Soft-Shelled Turtle 2 New Guinea: India, Bangladesh, Burma, Thailand, Malaysia, Cambodia, Vietnam, China, Philippines and Indonesia (inc.W Java, Borneo and Sumatra)  
Pelodiscus Chinese Soft-Shelled Turtles 2 China, N Vietnam, Taiwan, Far East Russia, Korea, Japan, Indonesia (Timor): introduced into Thailand and Hawaii  
Rafetus Euphrates and Swinhoe's Soft-Shelled Turtles  2 Turkey, Syria, Iraq, and Iran, Israel: China, poss. Vietnam  
Trionyx Nile Soft-Shelled Turtle (NA to Chinese species) 2 River systems of W & C Africa and the Nile; Eastern Mediterranean; China Now the only two members of the formerly large genus Trionyx. T. triunguis has apparently adapted to a maritime existence off the coasts of the Eastern Mediterranean in addition to its normal freshwater habitats.

Bibliography

Turtles and Tortoises of the World, David Alderton, Blandford, London 1999.

Schildkröten, Gerhard Müller, Eugen Ullmer, Stuttgart 1995.

A Field Guide to the Reptiles of East Africa, Stephen Spawls, Kim Howell, Robert Drewes and James Ashe, Natural World/Academic Press, London 2002.

Field Guide to Snakes and other Reptiles of Southern Africa, Bill Branch, Struik, Capetown 1998.

Links

Index of articles on soft-shelled turtles

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