''Mauremys reevesii'', commonly known as the Chinese pond turtle, the Chinese three-keeled pond turtle, or Reeves' turtle, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Geoemydidae, a family which was formerly called Bataguridae. The species is native to East Asia. It is one of the two most commonly found species used for

divination Divination () is the attempt to gain insight into a question or situation by way of an occultic ritual or practice. Using various methods throughout history, diviners ascertain their interpretations of how a should proceed by reading signs, ...

that have been recovered from

Shang dynasty The Shang dynasty (), also known as the Yin dynasty (), was a Chinese royal dynasty that ruled in the Yellow River valley during the second millennium BC, traditionally succeeding the Xia dynasty and followed by the Western Zhou d ...

sites.

Description

While the species typically appears to have a brown shell, dark grey skin, with yellow markings on the neck and yellow irises,

melanism Melanism is the congenital excess of melanin in an organism resulting in dark pigment. Pseudomelanism, also called abundism, is another variant of pigmentation, identifiable by dark spots or enlarged stripes, which cover a large part of the bod ...

is well documented in males, where the entirety of the animal including the eyes becomes completely black and the yellow markings are lost. Melanism only occurs in mature males over 7 years old. Old females may sometimes also develop darker shells and fewer markings. Certain populations of Reeve's turtles may exhibit megacephaly. Megacephalic turtles have much larger and broader heads, and hypertrophied jaws muscles. In at least one other species of turtle, it appears that megacephaly may not be genetically linked, instead developing in individuals as a response to a heavily durophagous diet. File:Chinemys reevesii 04.jpg File:Chinese Pond Turtle (Mauremys reevesii).jpg, Melanistic male, in Japan (introduced) File:Mauremys reevesii 356786109.jpg, In Japan (introduced)

Geographic range

''Mauremys reevesii'' is native to

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

and

Korea Korea is a peninsular region in East Asia consisting of the Korean Peninsula, Jeju Island, and smaller islands. Since the end of World War II in 1945, it has been politically Division of Korea, divided at or near the 38th parallel north, 3 ...

, and is thought to have been introduced to

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

in historic times; it was previously thought to be native to both these regions. The species is thought to have been introduced to Japan from the Korean Peninsula near the end of the 18th century. Introduced populations of ''M. reevesii'' may serve as a threat to the native turtles of these regions due to its propensity for hybridization.ATTWG (2000)

East Timor

During surveys in

East Timor Timor-Leste, also known as East Timor, officially the Democratic Republic of Timor-Leste, is a country in Southeast Asia. It comprises the eastern half of the island of Timor, the coastal exclave of Oecusse in the island's northwest, and ...

(Timor-Leste), a small but well-established population of ''M. reevesii'' was found living in marshes near the city of

Dili Dili (Portuguese language, Portuguese and Tetum language, Tetum: ''Díli'') is the Capital city, capital and largest city of Timor-Leste. It lies on the northern coast of the island of Timor, in a small area of flat land hemmed in by mountai ...

. The species is not native to the island and was possibly introduced by locals of Chinese origin. East Timor is home to the Roti Island snake-necked turtle (''Chelodina mccordi)'', more specifically the

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

''C. m. timorensis'' (sometimes considered a species of its own). Although the introduced population of ''M. reevesii'' is not known to present a risk to the native turtles ''

per se Per se may refer to: * '' per se'', a Latin phrase meaning "by itself" or "in itself". * Illegal ''per se'', the legal usage in criminal and antitrust law * Negligence ''per se'', legal use in tort law *Per Se (restaurant) Per Se is a New Amer ...

'', they could indirectly present a threat to the natives if confused. ''M. reevesii'' from the introduced population are sometimes captured to be sold to people of Chinese origin and this may cause problems if extended to the native turtles. A potential solution is to remove the introduced ''M. reevesii'' (thereby restricting the trade to captive farmed ''M. reevesii'').

Habitat and behaviour

''M. reevesii'' is semiaquatic, and basks in the sun on rocks or logs and can often be found leaving water to do so. They can usually be found in marshes, relatively shallow ponds, streams, and canals with muddy or sandy bottoms.

Conservation status

The Chinese three-keeled pond turtle (''M. reevesii)'' is threatened by competition with released pet

red-eared slider The red-eared slider or red-eared terrapin (''Trachemys scripta elegans'') is a subspecies of the pond slider (''Trachemys scripta''), a semiaquatic turtle belonging to the Family (biology), family Emydidae. Native to the southern United States ...

s (''Trachemys scripta elegans''), overhunting (its

plastron The turtle shell is a shield for the ventral and dorsal parts of turtles (the Order (biology), order Testudines), completely enclosing all the turtle's vital organs and in some cases even the head. It is constructed of modified bony elements such ...

is used in

traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medicine, alternative medical practice drawn from traditional medicine in China. A large share of its claims are pseudoscientific, with the majority of treatments having no robust evidence ...

), capturing for the pet trade, and wild

habitat destruction Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

. The

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

considers ''M. reevesii'' an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

. This species, fortunately, breeds well in captivity.

Etymology

The specific name, ''reevesii'', is in honor of English naturalist John Reeves.

Hybridization

This species, ''Mauremys reevesii'', is notorious for its ability to produce hybrids with other Geoemydidae, even species that are only distantly related. The supposed new species "'' Mauremys pritchardi'' " was based on a hybrid of unknown origin between a male of this species and a female

yellow pond turtle The yellow pond turtle (''Mauremys mutica''), is a medium-sized (to 19.5 cm), semiaquatic turtle in the family Geoemydidae. This species has a characteristic broad yellow stripe extending behind the eye and down the neck; the carapace ranges ...

(''Mauremys mutica''). Furthermore, it has hybridized with the Chinese stripe-necked turtle (''Ocadia sinensis''), female Malayan box turtles (''Cuora amboinensis''), a male four-eyed turtle (''Sacalia quadriocellata''), and the

Japanese pond turtle The Japanese pond turtle (''Mauremys japonica''), also called commonly the Japanese pond terrapin and the Japanese pond tortoise, is a species of turtle in the family Geoemydidae endemic to Japan. Its Japanese name is ''nihon ishigame'', Japane ...

(''Mauremys japonica'') in captivity. This hybridization may pose a threat to the populations of native ''M. mutica'' and Chinese stripe-necked turtle (''M. sinensis'') in

, and the

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

''M. japonica'' in

. Any individuals that are available as pets therefore need to be kept separate from other members of the family.

Farming

High demand for turtle plastrons for Shang divination rites and archaeological findings of large caches of turtle shells has led some scholars to speculate that ''Mauremys reevesii'' may have been farmed for this purpose in antiquity. ''M. reevesii'' is one of the species raised on China's modern-day

turtle farm Turtle farming is the practice of raising turtles and tortoises of various species commercially. Raised animals are sold for use as gourmet food, traditional medicine ingredients, or as pets. Some farms also sell young animals to other farms, ei ...

s. According to a 1998 survey, 548 farms raised this turtle species in four provinces in China. The statistical data from different provinces were in different formats; however, two provinces reported 20,650 turtles living on 26 farms, with 5,000 animals reproduced annually; the other two provinces reported the total weight of their turtles, namely some 260 tons of these animals on 522 farms. Over the five-year period, 1990–1995, 13 traditional Chinese medicine factories consumed 430 tons of ''C. reevesii'' plastrons. GUO Yinfeng, ZOU Xueying, CHEN Yan, WANG Di & WANG Sung. ; also quoted in: Based on a more recent (2002) survey of 684 Chinese turtle farms (less than half of all 1,499 turtle farms that were registered at the time), researchers found that 2.8 million of turtles of this species (reported there as ''Chinemys reevesii'') lived on these farms, with some 566,000 specimens sold by farmers every year. The total weight of the annual product was 320 tons, with the estimated value of over US$6 million, which makes the market value of a Chinese pond turtle equal to around $12—about twice as much that of the most common farmed species, '' Pelodiscus sinensis''. Taking into account the registered farms that did not respond to the survey, as well as the unregistered producers, the total amounts must be considerably higher.

Pet trade

Chinese pond turtles are farmed for the pet trade. In captivity, they require similar care to

s (''T. s. elegans'').

References

External links

* https://web.archive.org/web/20081024163050/http://chinesische-dreikiel.npage.de/ *https://web.archive.org/web/20110320235607/http://nlbif.eti.uva.nl/bis/turtles.php?menuentry=soorten
ARKive''Chinemys reevesii''
The Reptile *http://www.biosch.hku.hk/ecology/hkreptiles/turtle/Mauremys_reevesii.html {{Taxonbar, from=Q495153 Chinemys Reptiles of China Reptiles of Japan Reptiles of Korea Reptiles of Taiwan Reptiles described in 1831 Taxa named by John Edward Gray Taxonomy articles created by Polbot Endangered Fauna of China