The Trionychidae are a taxonomic family of a number of turtle genera commonly known as softshells. They are also sometimes called pancake turtles (although they are distinct from the pancake tortoise). Softshells include some of the world’s largest freshwater turtles, though many can adapt to living in highly brackish areas.
Members of this family occur in Africa, Asia, and North America. Most species have traditionally been included in the genus Trionyx, but the vast majority have since been moved to other genera. Among these are the North American Apalone softshells that were placed in Trionyx until 1987.
- Kingdom: Animalia
- Phylum: Chordata
- Class: Reptilia
- Order: Testudines
- Suborder: Cryptodira
- Superfamily: Trionychia
- Family: Trionychidae
- Subfamilies: Cyclanorbinae
Flap-shell softshells are small-to-moderate-sized turtles. The smallest taxon is Lissemys (maximum adult CL, 37 cm) and the largest is Cyclanorbis elegans (to 60 cm). The biology of the African taxa Cycanorbis and Cycloderma is little studied; the South Asian Lissemys is somewhat better known.
All cyclanorbines are probably bottom dwellers like trionychines. They actively forage and also lie partially hidden in the bottom silt or sand, waiting for passing prey. They are presumably opportunistic omnivores, eating invertebrates, small vertebrates, and occasional plant matter.
These water-loving turtles live in all types of year-round fresh water, occasionally in ponds that dry up for part of the year. A few can swim into somewhat salty water for a brief time, but only one species, the Asian giant softshell, actually lives in the saltier waters of the coast.
Overall, members of this family live east of the Rocky Mountains in North America and in mainly warmer climates in northern Africa, southern Asia, and the Indo-Australian archipelago, which is near Australia. They have also been introduced elsewhere, including Hawaii.
Softshell turtles are eaten as a delicacy in most parts of their range, particularly in East Asia. A Chinese dish stews them with chicken. According to a 1930 report by Soame Jenyns, Guangdong restaurants had them imported from Guangxi in large numbers; “eaten stewed with almonds, roast with chili sauce or fried with bamboo shoots, they [were] considered a great delicacy.
For the most part, these turtles remain hidden for much of the day. They fall to the bottom of the lake, pond, or other watering hole where they live and wiggle their bodies back and forth until they are buried. When they move about in the water, they are excellent swimmers.
Many species sunbathe, or bask, to warm their bodies. Some spend several hours a day basking on logs that stick up out of the water or on the shoreline, but they typically dash back into the water at even the slightest disturbance. Some prefer to sunbathe by simply floating in the top layer of water.