Trionychidae is one of the largest turtle families out there with about 12 to 15 genera and about 25 to 30 species. The number of genera and species isn’t constant as some species are sometimes considered subspecies or subpopulations of other species.
Trionychidae belongs to the kingdom Animalia, the phylum Chordata, the class Reptilia, and the order Testudines.
Trionychidae occurs in Africa, North America, and Asia. A few trionychids have been spotted. These are believed to have swam across the sea from New Guinea. Also, there is no evidence of established wild populations of trionychids in Australia.
Trionychids are commonly referred to as softshell turtles. Instead of having a hard upper shell like most turtles, softshell turtles have a soft leathery upper shell (carapace).
Trionychidae can be found in freshwater and brackish water bodies with soft bottoms (for example rivers and streams with muddy substrates). The water bodies they inhabit usually have slow-moving water. The exception to this is giant softshell turtles that are known to inhabit water with strong currents.
Trionychidae hardly basks and are highly aquatic. Most trionychids only come to shore to lay eggs.
Trionychids are generally carnivorous omnivores. As such although they are known to ingest plant matter every now and then, their diets are composed almost entirely of animal foods such as frogs, fish, mollusks, insects, and crustaceans.
The family Trionychidae was first described and named by the Austrian biologist Leopold Fitzinger in 1826.
Table of Contents
Species Within The Family Trionychidae
Genus Amyda
1. Asiatic Softshell Turtle
- Scientific Name: Amyda cartilaginea
- Other Names: Southeast Asian Softshell Turtle
- Length: 27.5 to 31.5 inches (70 to 80 cm)
- Mass:55 lbs (25 kg)
- IUCN Red List Status: Vulnerable
The Asiatic softshell is one of many softshell turtles endemic to Asia. The species is endemic to the Malay Peninsula, Thailand, Singapore, Malaysia, Indonesia, and Brunei.
This is a large turtle. While adults have smooth-looking shells, juveniles have rough-looking spells. The species’ carapace color ranges from green-brown to olive. Juveniles have dark shells. While adults’ shells are lighter in coloration.
The species is found in ponds, canals, lakes, and streams. These turtles seem to favor wetlands and can be found in swamps, marshes, and muddy rivers.
Genus Apalone
2. Florida Softshell Turtle
- Scientific Name: Apalone ferox
- Length: 6 to 30 inches (15 to 76 cm)
- Mass: 14.7 lb (6.6 kg)
- IUCN Red List Status: Least Concern
Apalone ferox is endemic to Florida, Alabama, Georgia, and South Carolina. This species’ geographic range spans the entire Florida peninsula. This species can be found in most freshwater habitats as well as brackish habitats.
Similar to most medium-sized softshell turtles, the species prefer habitats with slow-moving water like ponds, creeks, small rivers, swamps, and even marshes.
Apalone ferox adult size ranges from 6 to 30 inches. You may be wondering why adult sizes vary so much. That is because adult females are physically three to five times larger than adult males.
This turtle is normally kept as a pet.
3. Spiny Softshell Turtle
- Scientific Name: Apalone spinifera
- Length: 5 to 19 inches (13 to 48 cm)
- Lifespan: 50 years
- IUCN Red List Status: Least Concern
The spiny softshells are one of the largest freshwater turtles in the United States. The species is referred to as spiny because of the spiny projections found on the leading edge of the upper shell.
The species has a wide range from Ontario and Quebec in Canada to Chihuahua, Coahuila, Nuevo Leon, and Tamaulipas in Mexico.
The turtle is commonly found in streams, tributaries, rivers, lakes, and ponds. Apalone spinifera prefers shallow water, that is water with a depth of less than a meter.
Apalone spinifera is one of the turtles known to be able to breathe underwater. This respiration mechanism is important to the turtle when it hibernates.
4. Smooth Softshell Turtle
- Scientific Name: Apalone mutica
- Length: 10.5 to 14 inches (26.5 to 35.5 cm)
- Lifespan: 11 years in captivity
- IUCN Red List Status: Least Concern
This softshell can be found in Pennsylvania, New Mexico, Florida, and several states from the Midwest to Florida The turtle is found in the greater Mississippi basin, and the Escambia, Alabama, pearl, Sabine, Brazos, and colorado river systems.
There are two recognized subspecies and these are Apalone mutica mutica and Apalone mutica calvata.
As with most softshells, the smooth softshell is a strong swimmer and is found in large rivers with muddy substrates.
The smooth softshell can be called a carnivorous omnivore since it feeds mainly on animal food although it eats some fruits and seeds.
The members of the species are commonly kept as pets in the United States.
Genus Chitra
5. Asian Narrow-headed Softshell
- Scientific Name: Chitra chitra
- Average Adult Length: 59 inches (150 cm)
- Conservation Status: Critically Endangered
Chitra chitra is a critically endangered species and among the rarest turtles in the world. This softshell is endemic to Thailand, Malaysia, and Indonesia.
In Indonesia, the species is found in Jawa, and in Malaysia, the species is found in peninsular Malaysia.
There are two recognized subspecies and these are C. c. chitra and C. c. javanensis. C. c. chitra can be found in peninsular Malaysia and Thailand, while C. c. chitra can be found from eastern Java to Sumatra, a Sunda Islands of western Indonesia.
Chitra chitra can be found in the Mae Nam Pachi and Mae Khlong rivers in western Thailand; Solo River, the Brantas River, and Ciliwung River in Java; and the Pahang River in Malaysia.
The species is almost exclusively found in large clear rivers although they have also been found in muddy rivers as well as reservoirs.
6. Burmese Narrow-headed Softshell Turtle
- Scientific Name: Chitra vandijki
- Other Names: Indian striped curtain-foot
- Lifespan: 100+ years
- Conservation Status: Critically Endangered
The Burmese narrow-headed softshell turtle is endemic to Myanmar (formerly known as Burma) where it gets its common name as well as Thailand. In Myanmar, this turtle can be found in the Chindwin River, the Irrawaddy River, and perhaps the Sittaung River.
Very little is known about Chitra vandijki apart from the fact that some species have been found living in large rivers with sandbanks like the ones and it is entirely aquatic.
The species is estimated to reach reproductive maturity at the age of 10 to 15 years.
The species is known to eat shrimp, crabs, mollusks, and fish.
7. Indian Narrow-headed Softshell Turtle
- Scientific Name: Chitra indica
- Length: 43 inches ( 110 cm)
- IUCN Red List Status: Endangered
Another softshell endemic to India is the Indian narrow-headed softshell, this turtle is known as a narrow-headed softshell as it has a tiny narrow head. Previously this species was considered to be a subpopulation of Chitra chitra.
The Indian narrow-headed softshell is endemic to India as you can tell from its name. In India, it can be found in Harike Lake in Punjab and in Madhya Pradesh – the Chambal National Park – where it is widespread.
The species can primarily be found in the Mahanadi River, Godavari River, Ganges River, Indus River, and others. These river systems stretch across India, Nepal, Pakistan, and Bangladesh.
Genus Cyclanorbis
8. Nubian Flapshell Turtle
- Scientific Name: Cyclanorbis elegans
- Average Adult Length: 27.5 inches (70 cm)
- Mass: 45 lbs (20. 4 kg)
- Conservation Status: Critically Endangered
There are two turtles in the genus Cyclanorbis and Cyclanorbis elegans is one of them. This turtle can be found from West Africa to South Sudan.
The species used to be found in Ghana, Togo, Benin, Nigeria, Chad, Sudan, Ethiopia, and the Central African Republic but most of its population in the west is all gone. The only populations now remain in the White Nile basin in south Sudan and northern Uganda.
Very little is known about Cyclanorbis elegans. It has been found in large rivers. There is also no information on lifespan, maturity, and reproductive output.
The turtle is relatively large, reaching a length of 27.5 inches or 70 cm.
9. Senegal Flapshell Turtle
- Scientific Name: Cyclanorbis senegalensis
- Length: 14 inches (35 cm)
- Generation Length: 15 years
- IUCN Red List Status: Vulnerable
Although this species is called the gal flapshell, this turtle can be found throughout West Africa to South Sudan. The species can be found in Guinea-Bissau, Gambia, Liberia, Sierra Leone, Côte D’Ivoire, Ghana, Togo, Benin, Burkina Faso, Chad, Niger, Nigeria, Mali, Senegal, Sudan, South Sudan, and the Central African Republic.
The species can be found in freshwater bodies within its geographic range although it is mostly found in smaller water bodies. It can be found in the Nyanga River drainage area in northern Ghana, and along the Benue river and Niger river in Nigeria.
In places such as Benin, this turtle is found in large ponds.
Genus Cycloderma
10. Zambezi Flapshell Turtle
- Scientific Name: Cycloderma frenatum
- Length: 4 to 9 inches (11 to 22 cm)
- Lifespan: 27 to 31 years
- IUCN Red List Status: Endangered
Zambezi flapshell is endemic to southeastern Africa from Tanzania to central Mozambique and Zimbabwe.
This turtle is known as the Zambezi flapshell because it can be found in the Zambezi river and has flaps on the shell. This turtle is endemic to the Rufiji River basin, Lake Malawi (in Malawi), Rovuma River basin, Lower Zambezi river basin, and Lower Sabi river basin.
There is little information on the habitat usage of the flapshell. The little we know shows that adults live in large water bodies such as lakes and large rivers.
They have been found in lake Malawi and lake Urema which are large water bodies. In lake Malawi in particular, the species have been seen at depths of 500 m.
11. Aubry’s Flapshell Turtle
- Scientific Name: Cycloderma aubryi
- IUCN Red List Status: Vulnerable
C. aubryi is a softshell that can be found in Central Africa, particularly in Gabon, the Democratic Republic of Congo, Cabinda Province of Angola, and possibly the Central African Republic.
The species have been reported in Salonga National Park in the Congo and the Ogooué River in Gabon.
The species are generally found in freshwater and forest wetlands at altitudes of up to 1,600 ft. the species is commonly found in large water bodies within rainforests.
The species is predominantly carnivorous and is known to eat insects, fish, crayfish, and crabs. Juveniles are known to feed on small prey such as insects.
C. aubryi was listed in the IUCN red list in 2017, where it was listed as Vulnerable.
Genus Dogania
12. Malayan Softshell Turtle
- Scientific Name: Dogania subplana
- Length: 13.7 inches (35 cm)
- IUCN Red List Status: Least Concern
This is a turtle endemic to Malaysia and other countries in southeastern Asia including Indonesian islands Java and Sumatra, Myanmar, Brunei, Philippines, and Singapore.
This turtle is quite large and can reach a carapace length of 14 inches. The carapace is flattened.
Juveniles have reddish coloration on the neck which fades as the turtle grows. The carapace of this species is dark in coloration.
The species are the only species within the genus Dogania.
The species is found in rocky streams found at high elevations.
Genus Lissemys
13. Burmese Flapshell Turtle
- Scientific Name: Lissemys scutata
- Lifespan: 30 years
- IUCN Red List Status: Least Concern
This turtle is endemic to Asia and can be found mainly in Myanmar and perhaps in Yunnan province in China (although there is little evidence of this). Within its geographic range, the population of the species is stable.
River systems within which the species have been found in Salween river and Irrawaddy river.
The species is piscivorous and feeds mostly on aquatic animals. The species is mostly found in lowland seasonal wetlands and paddy fields.
L. scutata is traded in large quantities in East Asian food markets. As such, it could be possible that the species is now Vulnerable.
14. Sri Lankan Flapshell Turtle
- Scientific Name: Lissemys ceylonensis
- Local Names: Kiri Ibba (Sinhala), Pal Aamai (Tamil)
- Generational length: 20 years
- IUCN Red List Status: Vulnerable
Lissemys ceylonensis is commonly called Soft-shell terrapin, Mud Turtle, and Sri Lankan Flapshell Turtle. In Tamil, it is called Pal Aamai. And in Sinhala, it is called Kiri Ibba.
The species can be found in Sri Lanka as you may already have guessed from the name. The species is widely distributed.
While Lissemys ceylonensis is still fairly common within its geographic range, it is believed that the wild populations have likely seen a population decline of over 30% over the last 60 years.
Lissemys ceylonensis is an aquatic species that comes out to bask daily. The species is commonly found in low current water bodies including freshwater habitats and brackish water habitats.
15. Indian Flapshell Turtle
- Scientific Name: Lissemys punctata
- Common Names: matia, sundri (Hindi), til kachim (Bengali), pal aamai (Tamil)
- Length: 14 inches ( cm)
- Lifespan: years
- IUCN Red List Status: Vulnerable
Lissemys punctata is endemic to India. This turtle is fairly large and can reach over a foot in carapace length.
There are three recognized subspecies and these are L. p. vittata, L. p. andersoni, and L. p. punctata. Sri Lanka’s Lissemys ceylonensis was previously considered a subpopulation.
The species is fairly common throughout mainland India and the Indian subcontinent as a whole except for the Tahr Desert. L. p. andersoni can be found in the Ganga river, Indus river in Pakistan, Nepal, Bangladesh, and of course India, L. p. vittata can be found in central India, and L. p. andersoni can be found in southern India.
Genus Nilssonia
16. Black Softshell Turtle
- Scientific Name: Nilssonia nigricans
- Length: 35.5 inches (90 cm)
- Mass: 120 lb (54.5 kg)
- Lifespan: 100+ years
- IUCN Red List Status: Critically Endangered
The black Softshell turtle is a critically endangered species on the verge of extinction. This species used to be endemic to the Brahmaputra river basin in Bangladesh and India. In recent times, however, it can only be found in Assam.
Most of the known population is limited to the Bayazid Bastami shrine at Chittagong. Individuals have been spotted in several places such as Guwahati in Assam, and Udaipur in Tripura.
The black softshell is black in coloration and is similar in appearance to the Indian peacock softshell and the Ganges softshell. The black softshell is a large freshwater turtle.
Black softshell is known to feed on food provided by humans./ this races from meat, fruits, and grains.
17. Burmese Peacock Softshell Turtle
- Scientific Name: Nilssonia formosa
- IUCN Red List Status: Critically Endangered
Nilssonia formosa is one of the five species in the genus Nilssonia which include the Indian peacock softshell and the Ganges softshell, black softshell, and Leith’s softshell.
This turtle is critically endangered and there is little information on the species because of this. The species is known to be found in Myanmar (Burma), and perhaps Thailand.
There have been reports of the species being spotted in Karbi Anglong district in Assam which is in India. Another specimen was also spotted near Yunnan in China.
18. Indian Softshell Turtle
- Scientific Name: Nilssonia gangetica
- Other Names: Ganges Softshell Turtle
- Adult Length: 28 inches
- Conservation Status: Endangered
Nilssonia gangetica goes by many different names. Its Hindu names include patal, kachua, and kathawah. Its Bengali name is Ganga kachim.
This turtle is considered a giant turtle. Several other giants can be found under the genus Nilssonia.
The species is large in size and has a dark olive to green carapace which has eyelike patterns.
The species can be found in several river basins including the Indus River, Mahanadi River, Narmada River, and Ganga River. As such, they occur in India, Bangladesh, Pakistan, and Afghanistan.
Nilssonia gangetica is an aquatic turtle found in rivers and other large water bodies.
19. Leith’s Softshell Turtle
- Scientific Name: Nilssonia leithii
- Local Names: Nadi tabelu (Telugu), parisal aamai (Tamil), pale poo (Kannada)
- Length: 25 inches (64 cm)
- IUCN Red List Status: Critically Endangered
N. leithii is another endangered Nilssonia. The genus Nilssonia contains endangered and critically endangered species.
N. leithii can be found in peninsular India in states such as Odisha, Tamil Nadu, Maharashtra, Madhya Pradesh, Kerala, Karnataka, and Andhra Pradesh. Some protected habitats of the species are Sathyamangalam Tiger Reserve and Mudumalai Wildlife Sanctuary in Tamil Nadu; and Mudumalai Wildlife Sanctuary.
As with other Nilssonia, N. leithii is quite large. This turtle can reach a carapace length of 24 inches. The carapace is flattened as you would expect and is olive in coloration. The plastron is cream.
N. leithii is a carnivorous omnivore and feeds on fish, mollusks, crabs, and mosquito larvae. It also ingests small amounts of aquatic plants.
20. Indian Peacock Softshell Turtle
- Scientific Name: Nilssonia hurum
- Local Names: dhum kachim (Bengali), charpaiya, kachua, kathawah (Hindi),
- Length: 23.5 inches (60 cm)
- IUCN Red List Status: Endangered
This species is similar in appearance to all the other turtles found within the genus Nilssonia and has been confused with other species within the genus. The species is called the peacock softshell because of the eye-like patterns on its carapace.
In India, it can be found in places such as Assam, Madhya, Uttar Pradesh, and several others. The turtle is endemic to northern, eastern, and central India, eastern Pakistan, southern Nepal, and Bangladesh.
Although omnivorous, the species feed mostly on animal foods such as frogs, fish, prawns, snails, earthworms, and even carrions. Hatchlings and juveniles feed on small fish and mosquito larvae.
Genus Palea
21. Wattle-necked Softshell Turtle
- Scientific Name: Palea steindachneri
- Length: 14 to 17.5 inches (36 to 44.5 cm)
- IUCN Red List Status: Critically Endangered
Palea steindachneri is the only species within its genus. This turtle is critically endangered and also known as Steindachner’s soft-shelled turtle.
The species is a relatively large softshell turtle, although it is not as large as many of the softshells discussed here. Males are considerably smaller than females.
While males reach adult lengths of 14 inches, females reach adult lengths of 17.5 inches. Adult males however have longer tails.
The species can be found in Vietnam, Laos, and China in Yunnan, Hainan, Guizhou, Guangxi, and Guangdong.
The species has been collected for human consumption. In Vietnam and China, thousands of wattle-necked softshells are raised each year for human consumption.
Genus Pelochelys
22. Southern New Guinea Giant Softshell Turtle
- Scientific Name: Pelochelys bibroni
- Common Names: kiya eise (Suki), sokrere (Arammba)
- Length: 39.5 inches (100 cm)
- Mass: 260 lb (120 kg)
- IUCN Red List Status: Vulnerable
The New Guinea giant softshell is a turtle endemic to New Guinea as you may have figured out from the name.
It is possible that the turtle can be found in Australia but there is no confirmation of the wild population in Australia. The individuals spotted off the northern coast of Australia swarm from New Guinea as this turtle is tolerant to high salinity.
The species can be found in lowland rivers and even deltas and large estuaries. It may be a freshwater turtle but it can survive and thrive just fine in saline habitats.
As you can tell, the New Guinea giant softshell is a huge freshwater turtle and among the biggest there is.
23. Northern New Guinea Softshell Turtle
- Scientific Name: Pelochelys signifera
- Other Names: Variegated Giant Softshell Turtle
- Length: 35.5 to 39.5 inches (90 to 100 cm)
- Mass: 260 lb (120 kg)
- IUCN Red List Status: Vulnerable
Northern New Guinea softshell turtle is closely related to the southern New Guinea giant softshell turtle. In fact, both species can be found within the same genus.
This species can be found in northern New Guinea (north of the Central Range) as you may have already guessed from the chelonian’s name. The southern New Guinea giant softshell turtle is then found south of the Central Range.
The species can be found in the Ramu River basin, Wanggar River, Sepik River basin, and Mamberamo River basin.
The species is aquatic and known to enter marine environments. The species is postulated to eat crabs, prawns, and fish.
24. Asian Giant Softshell Turtle
- Scientific Name: Pelochelys cantorii
- Other Names: Cantor’s Giant Softshell Turtle
- Length: 28 to 39 inches (70 to 100 cm)
- IUCN Red List Status: Critically Endangered
This species has all but disappeared. The species can be found across East Asia from Bangladesh to the Philippines and Indonesia. It can normally be found in freshwater streams and rivers with low currents.
Pelochelys cantorii has a smooth olive coles carapace with dark spots. This turtle is massive and can grow to lengths of 40 inches and reach a mass of 220 lbs.
The species is mostly carnivorous and feeds on fish, mollusks, and crustaceans. It is also known to eat aquatic vegetation.
Pelochelys cantorii can survive for hours without breathing. Adults are known to surface to breathe just twice a day.
Genus Pelodiscus
25. Chinese Softshell Turtle
- Scientific Name: Pelodiscus sinensis
- Length: 11 to 13 inches ( cm)
- Lifespan: 25 years
- IUCN Red List Status: Vulnerable
The Chinese softshell is a very popular turtle. It is sought after by many turtle enthusiasts out there.
This turtle is endemic to China as you may have guessed from the name. Because of the popularity of the turtle, it has been introduced in Brazil, Spain, Hawaii, Taiwan, and several other Asian countries.
The species can be found from Inner Mongolia to Guangxi. The species live in brackish and freshwater habitats such as creeks, canals, ponds, lakes, and rivers.
The species is a carnivorous omnivore as they feed mostly on animal foods such as insects, mollusks, crustaceans, and fish. They also feed on seeds.
Genus Rafetus
26. Euphrates Softshell Turtle
- Scientific Name: Rafetus euphraticus
- Length: 26.4 inches (68 cm)
- Mass: 44 lb (20 kg)
- IUCN Red List Status: Endangered
Rafetus euphraticus is a softshell that is commonly found in the Euphrates Tigris river system.
The Euphrates river where it is commonly found gives the softshell its common name. This turtle can be found in Iraq, Iran, Turkey, and Syria where the river system runs.
The species is quite large for a freshwater turtle. It is also large for a softshell turtle although as huge as giant softshells.
This species weighs up to 44 lbs, and can reach lengths of 2.2 feet. Both males and females are similar in size and appearance. The overall coloration of the species is dull olive.
27. Yangtze Giant Softshell Turtle
- Scientific Name: Rafetus swinhoei
- Average Adult Length: 39 inches (100 cm)
- Lifespan: 100+ years
- Conservation Status: Critically Endangered
Rafetus swinhoei is one of the rarest turtles in the world. This species is critically endangered and considered to be functionally extinct as there are only 3 mature individuals remaining.
The species’ geographic range used to be in the Yangtze River which gives the turtle its common name and Lake Tai. Both the river and lake can be found in southeastern China.
One male and one female could be found in the Suzhou Zoo in China up until April 2018 when the female died. These two turtles mated several times but the female laid no fertile eggs. Another individual, a male that lived in the Red River in Hoan Kiem Lake in Viet Nam died in 2016.
A female was discovered in Dong Mo Lake, west of Hanoi in VietNam. One last Yangtze giant softshell was found in Xuan Khanh Lake also found in Viet Nam.
Little is known about these turtles since they are rare. The female that died in Suzhou Zoo in China was well over 90 years old. The male is also over 100 years old.
Genus Trionyx
28. African Softshell Turtle
- Scientific Name: Trionyx triunguis
- Length: 37.5 inches (95 cm)
- Lifespan: 24 to 45 years
- IUCN Red List Status: Vulnerable
Trionyx triunguis is one of the more popular softshells in the world. This turtle is also known as the Nile softshell as it is endemic to the Nile river.
The species is aquatic and only comes to shore to lay eggs. The species can be found in the Blue Nile, the White Nile, and the Sombreiro River.
With a carapace length of 37.5 inches, this is one of the largest freshwater turtles in the world. This turtle also has an olive carapace with white spots with yellow borders.
Similar to other softshell turtles, Trionyx triunguis can be found in large rivers and lakes with soft bottoms.
Frequently Asked Questions
Do trionychids make a good pet?
Small North American and Asian trionychids make excellent pets. They are easy to care for and hardy. Some of these are smooth softshell, Chinese softshell, and Florida softshell.
Is it legal to own trionychids as pets?
This depends on the species. Species from the genus Nilssonia are illegal to own as pets because they are endangered/critically endangered.
However many North American softshell turtles such as Apalone mutica (smooth softshell), Apalone ferox (Florida softshell), and Apalone spinifera (spiny softshell).
Whether or not a softshell turtle is legal to own also depends on your location. Check with your local laws before acquiring any turtle.
What other families is Trionychidae closely related to?
Trionychidae is closely related to the family Carettochelyidae.
This family includes a single species which is the pig-nosed turtle. The main difference between the two families is that Carettochelyidae has flippers while Trionychidae does not.
Which trionychids are endangered?
While most trionychids aren’t endangered, many are. Endangered trionychids include Rafetus swinhoei, Rafetus euphraticus, Chitra chitra, Chitra vandijki, Chitra indica, Nilssonia gangetica, Nilssonia nigricans, Nilssonia hurum, Nilssonia formosa, Nilssonia leithii, Cycloderma frenatum, Cyclanorbis elegans, Palea steindachneri, and Pelochelys cantorii.
Conclusion
Trionychids are unique-looking turtles. They have soft leathery carapaces instead of hard bony ones. This makes them easy to identify.
The size of Trionychidae ranges from 5 inches to as large as 59 inches. While many trionychids are kept as pets and are common, some such as Nilssonia nigricans are very rare and are on the verge of extinction.
Trionychidae is a highly aquatic family and the species within that family spend most of their time underwater. Most trionychids only come out to lay eggs. Trionychids also hardly bask.
Trionychids are commonly kept as pets. These include species such as the smooth softshell, the Chinese softshell, and the Florida softshell.