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Yangtze Giant Softshell Turtle - Rafetus swinhoei
#1
Scalesofanubis Wrote:Yangtze Giant Softshell Turtle - Rafetus swinhoei

[Image: Rafetus_swinhoei.jpg]

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Order: Testudines
Suborder: Cryptodira
Family: Trionychidae
Genus: Rafetus
Species: Rafetus swinhoei

[Image: yangtzesoftshellturtle.jpg]

The Yangtze giant softshell turtle (Rafetus swinhoei) is an extremely rare species of softshell turtle found in Vietnam and China. It is also known as the Red river giant softshell turtle, Shanghai softshell turtle, or Swinhoe's softshell turtle. In Chinese it is known as the specked softshell turtle (Chinese: 斑鱉; Pinyin: Bān Bīe). Only four living individuals are known and it is listed as critically endangered in the IUCN Red List. It is hoped that a pair at Suzhou Zoo in China will breed.

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The Yangtze giant softshell turtle is noted for its deep head with pig-like snout and eyes dorsally placed. This critically endangered species holds the title of being the largest freshwater turtle in the world.  It measures over 100 centimetres (39 in) in length and 70 centimetres (28 in) in width and weighs approximately 70–100 kilograms (150–220 lb).  The specimen caught from Vietnam weighed over 200 kilograms (440 lb). Its carapace, or shell can grow larger than 50 centimetres (20 in) in length and width. Its head can measure over 20 centimetres (7.9 in) in length and 10 centimetres (3.9 in) in width. The male is generally smaller than the female and has a longer, larger tail.

The Yangtze giant softshell turtle has been known to inhabit the Yangtze River and Lake Taihu, situated on the border of Jiangsu and Zhejiang provinces, in eastern China, and Gejiu, Yuanyang, Jianshui and Honghe in Yunnan province in southern China.
The last known specimen caught in the wild in China was in 1998 in the Red River between Yuanyang and Jianshui; it was then released. There are only four known living specimens in Vietnam and China, one each at Hoan Kiem Lake and Son Tay in Hanoi, Vietnam, and two in Suzhou zoo in China.
A specimen at the Beijing Zoo died in 2005, and another one at the Shanghai Zoo died in 2006; both of them were caught at Gejiu in the 1970s.

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In 1999, 2000, and 2005 turtles have reemerged from Hoan Kiem Lake on special occasions, when it was seen by a large audience and caught on film. It is believed that there is only a single turtle left in the lake.  In April 2011, it was captured because it had open sores that needed to be treated.

It eats fish, crabs, snails, water hyacinth, frogs, and leaves.

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The Yangtze giant softshell turtle may lay from 60 to more than 100 eggs. It nests at night and during the morning.  A fertile female from Changsha Zoo was introduced to the only known male in China, a 100 year old individual in Suzhou Zoo, in 2008. The female, who is over 80 years old, was said to settle in well after her 600 mile move and biologists were optimistic for breeding success. The move was coordinated by the Wildlife Conservation Society and the Turtle Survival Alliance.

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The species became known to the Western science in 1873, when John Edward Gray, the turtle expert at the British Museum, described the specimen sent to him from Shanghai by Robert Swinhoe. He named the species Oscaria swinhoei, and described it as "the most beautiful species of Trionychidae) that has yet occurred."
  In 1880, the Shanghai-based French Jesuit Pierre Marie Heude obtained several specimens of this turtle, from the Huangpu River (near Shanghai) and Lake Taihu (near Suzhou). He thought them sufficiently different from each other to describe them as five distinct species: Yuen leprosus, Yuen maculatus, Yuen elegans, Yuen viridis, and Yuen pallens.  The genus name, Yuen, presumably comes from the Chinese 鼋 (transcribed yüen in the Wade-Giles system, or yuan in the modern Hanyu Pinyin), which means a large turtle.
  Later zoologists classified these turtles as belonging to the Trionyx, Pelodiscus, and Pelochelys genera; it was only in 1987 that Meylan categorized this species under the Rafetus genus.  The placement of the related or conspecific Hoan Kiem turtle, Rafetus leloii, remains poorly known and controversial. Through work by Farkas et al., most junior synonym of the Yangtze giant softshell turtle, though some Vietnamese biologists, such as Ha Dinh Duc, who first described leloii, and Dr. Le Tran Binh insist that the two turtles are not the same species. Le points out genetic differences as well as differences in morphology.  However, Farkas et al. repeated their 2003 conclusion in 2011, citing that differences between specimens may be due to age and that the genetic sequences used were never sent to GenBank.

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  The Yangtze giant softshell turtle is on the brink of extinction due to habitat loss, hunting for subsistence and local consumption, and the use of the carapace and bones in medicine. Skulls are often kept as trophies.  A recent plan to build hydropower cascade of 12 dams on the Red River in China may flood all of its habitat and change the ecosystem of lower Vietnam.

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  Conservation efforts are concentrated on breeding captive turtles in China and searching for live specimens in the wild. An agreement was made to transfer the only known remaining female specimen located at the Changsha Zoo to the Suzhou Zoo to breed with the male specimen there. Also efforts are being made to improve conditions for breeding at both the Suzhou Zoo and Western Temple in Suzhou. A workshop on the Rafetus Conservation at Yunnan was held by CI-Shanshui. Local Chinese scientists are searching for the last existent individuals.  The two specimens were able to produce two clutches of eggs with over half of them being fertile, though unfortunately all of them perished before hatching.[15] The Turtle Survival Alliance released a statement, saying "A number of the eggs had very thin shells, suggesting that the diet of the animals prior to breeding was not optimal.".  The two turtle are now being prepared for another round of mating, while being fed a high calcium diet in an effort to strengthen the eggs. Liu Jinde, the director of the zoo said "We've worked very hard on this, We ought to succeed. The turtles are very healthy."
  The scientists began preparing to mate the two once again in May 2009, which fell within this species' breeding season.  But in the fall of 2009 the zoo announced that despite laying 188 eggs the eggs were infertile and would not hatch.  The Turtle Survival Alliance issued a statement explaining that the infertility was due in part to the turtle's poor diet and the group expressed concern that the zoo's patrons had thrown trash into the turtle's enclosure that, if eaten, could endanger the health of the turtles.  On June 15, 2010 the female laid a total number of 63 eggs. Half of the eggs were left in the sand to incubate naturally while the other half were moved incubate at varying levels of temperature and humidity. Once again, they were infertile.

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  The Hoan Kiem turtle (Rafetus leloii) is a controversial taxon of turtle from Southeast Asia, with one known living specimen in Hoan Kiem lake in Vietnam. Its status as a distinct species is controversial; although some Vietnamese scientists insist that the leloii is a distinct species from the Yangtze Softshell Turtle Rafetus swinhoei, others believe it is synonymous with the latter species. If the two forms are to be considered identical, there are four living specimens left in the world.

  Near the northern shore of Hoan Kiem Lake lies Jade Island, on which the Temple of the Jade Mountain is located. On June 2, 1967, a Hoan Kiem turtle died from injuries caused by an abusive fisherman that was ordered to net the turtle and carry it, but instead hit the turtle with a crowbar. The turtle's body was preserved and placed on display in the temple. That particular specimen weighed 200 kg (440 lbs) and measured 1.9 metres long (6 ft 3in).  Until that time, no one was sure if the species still lived.
  On March 24, 1998 an amateur cameraman caught the creature on video, conclusively proving the elusive creatures still survived in the lake. Prior to its recent rediscovery, the turtles were thought to be only a legend and were classified as cryptozoological.  In 2000, professor Ha Dinh Duc gave the Hoan Kiem turtle the scientific name Rafetus leloii.
  Presently, if leloii is considered to be identical to swinhoei, there are four living individuals. Three turtles are in captivity, two of them in Chinese zoos and another in Dong Mo (which appears to be a swinhoei), while the fourth being the controversial specimen in Hoan Kiem lake.  
  By the Spring of 2011, concerned with the Hoan Kiem specimen's more frequent than usual surfacing, and apparent lesions on its body, the city authorities started attempts to capture the giant reptile of Hoam Kiem Lake, and take it for medical treatment. On February 9, a local turtle farm operator, KAT Group, was chosen to prepare a suitable net to capture the sacred animal.  The first attempt, on March 8, 2011 failed, as the turtle made a hole in the net with which the workers tried to capture it, and escaped.  An expert commented, "It's hard to catch a large, very large soft-shell turtle."[7] On March 31, in an unusual act, the turtle went to the shore to bask in the sun.  Finally, on April 3, 2011 the giant turtle was netted in an operation that involved members of the Vietnamese military. The captured creature was put into an enclosure constructed on an island in the middle of the lake, for study and treatment.  The turtle was determined to be female, and genetic research suggested it was distinct from the swinhoei turtles in China, and even the specimen from Dong Mo.  Some witnesses believe there are at least two or three turtles living in Hoan Kiem Lake and that the "smaller" one appears more regularly.
  R. leloii is now generally believed to be identical to, and therefore a synonym of, R. swinhoei.  However, Ha Dinh Duc, who first described leloii, and other Vietnamese scientists such as Le Tran Binh, believe that that the two forms are not identical, pointing out that swinhoeii is slightly smaller than the Hoan Kiem turtle and that the face is not spotted in leloii.
Duc has also hypothesized that Emperor Thái Tổ of the Lê Dynasty brought the turtles from Thanh Hóa Province and released them in Hoan Kiem Lake. Recently, Duc and some researchers found skeletons of giant turtles in Yen Bai, Phu Tho and Hoa Binh Provinces.

  Despite eyewitness sightings of two or more turtles, Professor Duc believes that there is only one specimen left in the Hoan Kiem Lake.  Peter Pritchard, a renowned turtle biologist, believes that there are no more than five specimens left.  
  The lake itself is both small and shallow, measuring 200 metres wide, 600 metres long, and only two meters deep. It is also badly polluted, although the turtles could conceivably live underwater indefinitely, coming to the surface only for an occasional gulp of air or a bit of sun. According to Pritchard, the turtles are threatened by municipal "improvements" around the lake. The banks have been almost entirely cemented over, leaving only a few yards of rocky beach where a turtle might find a place to bury her clutches of 100 or more eggs.
  Plans are underway to clean the lake of pollution, and the construction of an artificial beach has been proposed to facilitate breeding.  Dredging the lake, to clean up its bottom, was carried out in March 2011.
  Professor Duc is currently organizing people to protect this animal and is quoted as saying, "We hope that we will find a partner for the turtle in Ho Guom, so that our legendary animal could avoid extinction." Believing the turtle to be different from swinhoei, he is against the idea of crossbreeding turtles of the two kinds.  Some view the idea that the species are distinct as being politically and culturally motivated by anti-Chinese sentiment.
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#2
World's Largest Freshwater Turtle Nearly Extinct
The last known pair of Yangtze giant softshell turtles mated again in June.


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A Yangtze giant softshell turtle—one of the last four known—gets a checkup in Hanoi, Vietnam, in 2011.

Kaitlin Solimine
for National Geographic
Published July 1, 2013

The fate of a species is resting on the shells of two turtles at China's Suzhou Zoo.

In June, researchers collected eggs from the last mating pair of the critically endangered Yangtze giant softshell turtle (Rafetus swinhoei) in the hopes that at least one will be fertile.

The 220-pound (100-kilogram) freshwater giant, which spends most of its life burrowing in mud, was once common in its namesake Yangtze River, China's Lake Taihu and Yunnan Province, and parts of Vietnam.

By the late 1990s, however, human encroachment and poaching for use of the shells in Chinese traditional medicine rapidly depleted the population. Now, a total of four animals are known—two wild males in Vietnam and the mating pair at Suzhou Zoo.

It's the team's sixth year of breeding the turtles at the zoo, which is not far from Shanghai. So far, none of the eggs have hatched.

Researchers can't pinpoint the reason for the infertility, but they suspect a combination of factors, including poor sperm quality due to the male's age—roughly a hundred—an improper mating posture, and stress on the female.

Because the turtles are the last in captivity and too much human interaction could kill them, sperm samples cannot be taken nor tests run. Still, scientists are hoping that this year will be the lucky one. 

"The resurrection of this iconic species in the wild, the largest freshwater turtle in the world, would be a symbol of hope," said Gerald Kuchling, founder of the Australia-based group Turtle Conservancy and a turtle-reproduction expert.

"Miraculous" Find

As is the case with many near-extinct species, by the time scientists realized the extent of the turtle's decline, the species was almost gone.

In 2006, the U.S. nonprofit Turtle Survival Alliance asked Kuchling to establish the sex of the last three captive giant softshell turtles in China, which at the time lived at the Shanghai Zoo, Suzhou Zoo, and Suzhou's West Garden Buddhist Temple. 

When Kuchling landed in China in 2007, the Shanghai Zoo and Buddhist Temple individuals had already died. The Suzhou Zoo male was the last known Chinese survivor. Researchers sent an all-points bulletin to every zoo in the nation in the off chance a turtle had been misidentified.

Their call was answered: A photograph of a turtle at the Changsha Zoo looked promising. Kuchling, along with Lu Shunqing, China director for the Wildlife Conservation Society, traveled to Changsha, where they confirmed it was a Yangtze giant softshell—and a female to boot.

"It's a bit miraculous we found her," said Emily King, the Suzhou Zoo breeding program's field assistant.

Breeding Roadblocks

Although moving the Changsha Zoo's female—the younger of the pair at then 80 years old—to the Suzhou Zoo was risky because of the stress it would cause the animal, zoo officials and researchers had no choice.

Surveys in the wild consistently had turned up no Yangtze giant softshells aside from the two males already known in Vietnam. These individuals haven't been captured because catching and transporting them could be fatal.

Either the Suzhou Zoo pair would mate, or the species would go extinct.

In May 2008, after much red tape, the female finally arrived in Suzhou. Just over a week later, the turtles mated-despite the fact that the female had likely never met a male. 

A month later, the female laid her first clutch of 45 eggs on the zoo enclosure's beach, 32 of which were incubated.

To determine if an egg is fertile, the scientists candle them, or hold a candle behind the egg to look for a developing embryo.

The initial batch yielded no hatchlings. Later that month, a second batch was equally infertile.

The turtles mated each of the following years, but with the same result.

Di Min, a zoologist at the Suzhou Zoo, said when the program started there was talk about assisted reproductive techniques, a kind of "turtle IVF."

"But the best and safest is they breed naturally. There's only this pair—if we lose one, especially the female, we don't have any chance."

The team doesn't know how much longer the zoo turtles will live or continue to mate, but scientists suspect Yangtze giant softshells can live well over a hundred years. 

Turtle Team Optimistic

Despite these setbacks, scientists are staying optimistic about saving the turtle.

"We have these two [Suzhou] animals, and hopefully in the very near future, as opposed to far distant, we'll have baby Rafetuses on our hands," added field assistant King.

"In one shape or another, the program will go on, because everyone is invested in having this species continue."

http://news.nationalgeographic.com/news/2013/07/130703-china-yangtze-giant-softshell-turtle-animal-science/ 
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#3
hindustan times

Last female of rare Yangtze giant softshell turtles dies in China

The animal was one of four Yangtze giant softshell turtles known to be remaining in the world. The Suzhou zoo, where the female turtle lived, also houses a male Yangtze giant softshell turtle. The other two live in Vietnam, but their genders are unknown.
Updated: Apr 14, 2019 23:04 IST
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The only known female Yangtze giant softshell turtle who died at the Suzhou zoo in China on Monday.(VCG/ Getty/File Photo)

The only known female member of one of the world’s rarest turtle species has died at a zoo in southern China, officials said on Sunday.
The animal was one of four Yangtze giant softshell turtles known to be remaining in the world. The Suzhou zoo, where the female turtle lived since 2008 when she was moved from the Changsha Ecological Zoo, also houses a male Yangtze giant softshell turtle.
She was moved to mate with the male turtle, who is reportedly over 100 years old, a zoo employee told China’s Global Times on condition of anonymity.
The other two turtles live in Vietnam, but their genders are unknown.

The turtle died on Saturday afternoon, the Suzhou city government said in a statement, citing the zoo. It said experts have already used technology to collect the turtle’s ovarian tissue for future research.
The state-run People’s Daily reported that the turtle was over 90 years old and had undergone a fifth attempt at artificial insemination shortly before she died.
A medical examination found the turtle to be in good health prior to the procedure, the People’s Daily said, and the artificial insemination appeared to go smoothly.
But the turtle died the following day.
The Rafetus swinhoei, more popularly known as Yangtze giant softshell turtles, originated in China, making their homes in the Yangtze River and Taihu Lake, according to the People’s Daily.
The species is often referred to as the most endangered turtle in the world.
Loss of habitat and poaching are among the reasons for the decline of the species’ population, according to a report by Mongabay, a conservation and environmental science news service.
Suzhou authorities said Chinese and foreign experts are investigating the cause of the turtle’s death. “The cause of death... will be announced later by the China Wildlife Conservation Association,” a Suzhou zoo employee told Global Times.
(Associated Press contributed to this story)
First Published: Apr 14, 2019 16:38 IST

https://www.hindustantimes.com/world-new...GN3E4oIZLs
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