The Asian giant softshell turtle (''Pelochelys cantorii''), also known commonly as Cantor's giant softshell turtle and the frog-faced softshell turtle, is a

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 appropriat ...

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 incl ...

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked t ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Trionychidae The Trionychidae are a taxonomic family of a number of turtle genera, commonly known as softshell turtles. The family was erected by Leopold Fitzinger in 1826. Softshells include some of the world's largest freshwater turtles, though many can a ...

. The species is native to

Southeast Asia Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical south-eastern region of Asia, consisting of the regions that are situated south of mainland ...

. The species is critically endangered and in the 20th century has disappeared from much of its former range.

Taxonomy

''P. cantorii'' is not found in

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; id, Papua, or , historically ) is the world's second-largest island with an area of . Located in Oceania in the southwestern Pacific Ocean, the island is separated from Australia by the wide Torres ...

, while the two other members of the genus ''

Pelochelys ''Pelochelys'' is a genus of very large softshell turtles in the family Trionychidae. They are found from peninsular India northeast to southern China, and south to Southeast Asia and New Guinea. The species in this genus, while still being fr ...

'', '' P. bibroni'' and '' P. signifera'' are both restricted to New Guinea. ''P. cantorii'' is relatively unstudied, and the current species may actually be composed of several

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

. One study from 1995 showed that what was once thought to be ''P. cantorii'' in New Guinea was actually ''P. bibroni'', and the earlier studies of ''P. cantorii'' only described populations farther to the west.

Description

The Asian giant softshell turtle has a broad head, and small eyes close to the tip of its snout. The

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

is smooth and olive-colored. Juveniles may have dark-spotted carapaces and heads, with yellow around the carapace. Despite reports that it can grow up to in length and is the world's largest extant freshwater turtle, this maximum size and title is murky at best. Apparently the largest specimen carapace length, , known is considered suspect and the heaviest specimen known (weighing approximately was actually a misidentified

Yangtze giant softshell turtle The Yangtze giant softshell turtle (''Rafetus swinhoei''), also known as the Red River giant softshell turtle, the Shanghai softshell turtle, the speckled softshell turtle, and Swinhoe's softshell turtle, is an extremely rare species of turtle i ...

. A more realistic range of carapace length for this species is reportedly and it is one of about a half-dozen giant softshell turtles from three genera that reach exceptionally large sizes, i.e. in excess of in mass.

Behavior and reproduction

''P. cantorii'' is an

ambush predator Ambush predators or sit-and-wait predators are carnivorous animals that capture or trap prey via stealth, luring or by (typically instinctive) strategies utilizing an element of surprise. Unlike pursuit predators, who chase to capture prey ...

and primarily

carnivorous A carnivore , or meat-eater (Latin, ''caro'', genitive ''carnis'', meaning meat or "flesh" and ''vorare'' meaning "to devour"), is an animal or plant whose food and energy requirements derive from animal tissues (mainly muscle, fat and other ...

, feeding on

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapoda, decapods, ostracoda, seed shrimp, branchiopoda, branchiopods, argulidae, fish lice, krill, remipedes, isopoda, isopods, barnacles, copepods, ...

mollusks Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...

and fish (although some aquatic plants may also be eaten). The turtle spends 95% of its life buried and motionless, with only its eyes and mouth protruding from the sand. It surfaces only twice a day to take a breath, and lays 20–28 eggs sized around in diameter in February or March on riverbanks.

Morphological variation

Asian Giant Softshell Turtle at Philippine National Museum

Morphological differences in neural bone count have been noted between specimens of ''P. cantorii'' found in the Philippines and specimens found in mainland Asia.

Etymology

The specific name, ''cantorii'', is in honor of Danish zoologist

Theodore Edward Cantor Theodore Edward (Theodor Edvard) Cantor (1809–1860) was a Danish physician, zoologist and botanist. Born to a Danish Jewish family, his mother was a sister of Nathaniel Wallich. Cantor worked for the British East India Company, and made natur ...

Geographic range and habitat

The species ''P. cantorii'' is primarily found in inland, slow-moving, freshwater rivers and streams. Some evidence indicates that its range extends to coastal areas, as well. It occurs in eastern and southern

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mo ...

Burma Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federal constitutional monarchy consists of thirteen states and three federal territories, separated by the South China Sea into two regions: Peninsular Malaysia and Borneo's East Mal ...

Laos Laos (, ''Lāo'' )), officially the Lao People's Democratic Republic ( Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ, French: République démocratique populaire lao), is a socialist s ...

Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailand ...

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making ...

, eastern and southern

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...

, the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

(

Luzon Luzon (; ) is the largest and most populous island in the Philippines. Located in the northern portion of the Philippines archipelago, it is the economic and political center of the nation, being home to the country's capital city, Manila, as ...

and

Mindanao Mindanao ( ) ( Jawi: مينداناو) is the second-largest island in the Philippines, after Luzon, and seventh-most populous island in the world. Located in the southern region of the archipelago, the island is part of an island group of ...

), and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Gui ...

(

Kalimantan Kalimantan () is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area. The non-Indonesian parts of Borneo are Brunei and East Malaysia. In Indonesia, "Kalimantan" refers to the whole island of Borneo. In 2019, ...

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mo ...

, and

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

Conservation

The Asian giant softshell turtle is classified as a Critically Endangered by the

IUCN 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 ...

and has been forced out through habitat destruction, disappearing from much of its range. Prior to 2007, it was last seen in Cambodia in 2003. A 2007 survey of one area of the

Mekong River The Mekong or Mekong River is a trans-boundary river in East Asia and Southeast Asia. It is the world's twelfth longest river and the third longest in Asia. Its estimated length is , and it drains an area of , discharging of water annual ...

in Cambodia found the turtle in abundance along a stretch of the river. In the Philippines, a juvenile Cantor's turtle known as “cagot" appeared and was captured by a fisherman along the Addalam River,

Cabarroguis Cabarroguis, officially the Municipality of Cabarroguis ( ilo, Ili ti Cabarroguis; tl, Bayan ng Cabarroguis), is a 3rd class municipality and capital of the province of Quirino, Philippines. According to the 2020 census, it has a population of 33 ...

Quirino Quirino, officially the Province of Quirino ( ilo, Probinsia ti Quirino; tl, Lalawigan ng Quirino), is a landlocked province in the Philippines located in the Cagayan Valley region in Luzon. Its capital is Cabarroguis. It is named after Elp ...

, Isabela. In 2001, this turtle was sent to

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = List of sovereign states, Count ...

and its identity confirmed. The reptile has been evaluated as an EDGE species by the

Zoological Society of London The Zoological Society of London (ZSL) is a charity devoted to the worldwide conservation of animals and their habitats. It was founded in 1826. Since 1828, it has maintained the London Zoo, and since 1931 Whipsnade Park. History On 29 ...

References

External links

"''Pelochelys cantorii'' ". The Reptile Database. No date.
Accessed May 18, 2007.

Accessed May 18, 2007. * ttps://web.archive.org/web/20120418062039/http://www.rubiahdivers.com/soft_shell_turtle_founded.html Soft Shell turtle discovered in Sabang Pulau Weh Sumatra Indonesia {{Taxonbar, from=Q2006609 Pelochelys Reptiles of China Reptiles of India Reptiles of Myanmar Reptiles of Vietnam Reptiles of Cambodia Reptiles of Laos Reptiles of Thailand Reptiles of Brunei Reptiles of Indonesia Reptiles of Malaysia Reptiles of the Philippines Reptiles of Papua New Guinea Reptiles described in 1864 Taxa named by John Edward Gray Turtles of New Guinea Reptiles of Borneo