Archive for category Sword Lake Turtle

Swinhoe’s Softshell Turtle: Captive Breeding Program 2016 Update

The annals and magazine of natural history : zoology, botany, anIt would appear that once again, this year’s attempts to breed two captive Swinhoe’s soft-shell turtle (Rafetus swinhoei), the world’s rarest freshwater turtle, have hit a wall. This situation has become even more dire after it was announced in January 2016 that the Sword Lake Turtle, one of the only four individuals known to exist in the wild or captivity, had been  had been found floating dead in Hoàn Kiếm Lake in central Hanoi, Vietnam.

Swinhoe’s softshell turtle has long been famous for it role in Vietnamese legend as the fabled Sword Lake Turtle, which inhabits Hoàn Kiếm Lake (“The Lake of the Returned Sword”) in Hanoi, Vietnam. But of the handful of Swinhoe’s softshell turtles known to scientists to exist in the wild or captivity in recent years, five have died since the 1990s, leaving only four remaining (until this year): one in Hoàn Kiếm Lake (now deceased), one in the wild in Đồng Mỏ Lake west of Hanoi, and two in captivity, the latter now both part of the Suzhou Zoo’s captive breeding program.

Since 2008, when the Changsha Zoo’s female, “China Girl,” was relocated to Suzhou, scientists at Suzhou Zoo have undertaken a captive breeding program with their older male turtle. But despite repeated bouts of courtship displays and mating between the pair in the years since, the resulting eggs have failed to hatch. Remediative actions to date, including steps to improve their diet by constructing a glass wall to prevent visitors from tossing junk food into their inclosure, provisioning the pair with a more natural diet (e.g. whole shrimp, freshwater crayfish, fishes, freshwater snails, frogs, quail, pigeons), and redesigning their enclosure to allow the pair more time together, have proven unsuccessful.

After the Suzhou Zoo’s captive breeding program reported in 2014 that their male may be infertile, the future of the program and the species were both at risk. In a move that lets slip their growing concern for the species’ survival, in the spring of 2015 researchers attempted what had until recently been considered by stakeholders too controversial – artificial insemination.

In April 2016, the Turtle Survival Alliance reports that herpetologist Gerald Kuchling oversaw a surgical artificial insemination attempt that injected the semen directly into the female’s oviducts while the turtle was anesthetized. Kuchling was able to closely examine the male’s penis during past insemination attempts and found that it had been mangled, possibly during an ill-fated encounter with a second captive male several years ago. Last year’s attempt involved depositing the sperm into the anesthetized female’s oviducts.

As she has in the past, this year the female laid 65 eggs at the Suzhou Zoo. However, when Kuchling candled the eggs in late June, all were found to be infertile.

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Swinhoe’s Softshell Turtle: The Death of a Legend

The annals and magazine of natural history : zoology, botany, anSince January 19th, when rumors about the death of the Hoàn Kiếm Turtle first surfaced, the Turtle Survival Alliance has now confirmed that indeed the lone Swinhoe’s (or Yangtze) soft-shell turtle (Rafetus swinhoei) that resided in Hoàn Kiếm Lake in central Hanoi, Vietnam, was found floating dead in the lake Tuesday. The passing of this individual makes the situation even more dire for the remaining three turtles, which together represent the last and only known individuals in existence of this, the world’s rarest freshwater turtle.

The Swinhoe’s softshell turtle had long been famous for it role in Vietnamese legend as the fabled Sword Lake Turtle that inhabited Hoàn Kiếm Lake. Of the handful of Swinhoe’s softshell turtles known to scientists to exist in the wild or captivity in recent years, five had died since the 1990s, leaving only four remaining: one in Hoàn Kiếm Lake, one in the wild in Đồng Mỏ Lake west of Hanoi, and two in captivity, the latter now both part of the Suzhou Zoo’s captive breeding program.

Since 2008, when the Changsha Zoo’s female, “China Girl,” was relocated to Suzhou, scientists at Suzhou Zoo have undertaken a captive breeding program with their older male turtle. But despite repeated bouts of courtship displays and mating between the pair in the years since, the resulting eggs have failed to hatch.

With the passing of this lonely, legendary turtle, it is perhaps fitting to remember it today more than ever through the legend that made it a cornerstone of Vietnamese mythology, a fairytale hero to Vietnamese schoolchildren, and an omen of good luck to all who were fortunate enough to catch a glimpse of the turtle surfacing in Hoàn Kiếm Lake over the years.

The following retelling is from the 2012 article I prepared on the history and natural history of this species in the journal Bibliotheca Herpetologica, and is excerpted here, below (a citation and link to the full article are provided below).

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The Legend of the Sword Lake Turtle

“In the six-hundred years since the Dragon King first guided the farmer king to victory, the legend of the Sword Lake Turtle has evolved in the telling. The heart of this legend roughly holds true to the historical record. Between 1418 and 1426, after enduring years of violent occupation under an invading force of the Chinese Ming, the farmer Lê Lợi raised an army of 500 volunteer soldiers – the Lam Son army – to free their country. Although Lê Lợi’s guerilla tactics demoralized and chipped away at the invader’s forces, the Ming occupation persisted (Trang 2006). It is here that the lines between legend and history blur.

As retold by Minh Trang in “Sự Tích Hồ Gươm (The Legend of Sword Lake)” (Trang 2006; see also Asian Turtle Conservation Network 2008), legend has it the Dragon King – witnessing from his underwater palace the Lam Son army’s struggle – sent forth the Golden Turtle (referred to as the “Golden Tortoise” in Trang 2006) to deliver a magical sword blade to Lê Lợi. Whether by design or by accident (here the legend is unclear on all counts), this blade was delivered, not to Lê Lợi, but to a fisherman, Lê Thận. Lê Thận cast his net three times, each time entangling it in the sword blade. It wasn’t until the third cast that Lê Thận, beguiled by the reappearing blade, tucked it in his belt and returned home. Soon thereafter, Lê Thận joined Lê Lợi’s resistance army.

One night, after stopping by Lê Thận’s quarters to visit, Lê Lợi noticed the blade on the wall, which began to glow in his presence. Inspecting the blade, Lê Lợi saw the radiance emanated from two words etched on the blade: “Thuận Thiên” (“Heaven Approves” or “The Will of Heaven”). Several days later, during a retreat of Lê Lợi’s guerilla army before an anticipated Ming attack, the farmer king again saw a strange glow – this time from the canopy of an ancient banyan tree. Upon closer inspection, Lê Lợi saw that it was a sword hilt decorated in gems and etched with the same divine words: “Thuận Thiên.”

When Lê Lợi and Lê Thận next crossed paths, Lê Lợi asked to see the blade; the blade and hilt were a perfect fit. Seeing this as a sign from heaven, Lê Thận knelt before Lê Lợi, bestowed him the sword, and swore his allegiance to the farmer king that he might save their people and their homeland (Trang 2006).

As word of Lê Lợi’s magical sword spread, his Lam Son army grew (Trang 2006, Friends of Vietnam Heritage 2008). Backed by a growing resistance some 350,000 soldiers strong, reinforced with horses and elephants, and – by legend’s score – armed with the magical sword that made Lê Lợi grow tall and gave him the strength of many men (Friends of Vietnam Heritage 2008), Lê Lợi destroyed the Ming forces and led his people to victory. After years of oppression, in 1427 the Chinese recognized the Vietnamese people’s independence. One year later, Lê Lợi was declared king under the title Lê Thái Tổ, founder of the Lê Dynasty (Friends of Vietnam Heritage 2008).

Not long after Lê Lợi became king, he was touring Lục Thuy (“Green Water”) Lake when the Golden Turtle emerged from the waters to retrieve the divine sword. By some accounts, the Golden Turtle asked for the sword’s return and Lê Lợi respectfully complied (Trang 2006); by others the messenger instead plucked it from Lê Lợi’s belt, inciting the king to retrieve it (Friends of Vietnam Heritage 2008). In the end, however, Lê Lợi acknowledged the sword’s return to the Dragon King and in tribute, renamed the waters Hồ Hoàn Kiếm, “The Lake of the Returned Sword” (Trang 2006, Friends of Vietnam Heritage 2008)” (Bettelheim 2012).

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Full Citation: Bettelheim, Matthew P. 2012. Swinhoe’s Softshell Turtle (Rafetus swinhoei): The Legendary Sword Lake Turtle of Hoan Kiem Lake. Bibliotheca Herpetologica 10(1): p 4-20.

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Swinhoe’s Softshell Turtle: Captive Breeding Program 2015 Update

The annals and magazine of natural history : zoology, botany, anWith news coverage of this year’s attempts to breed Swinhoe’s soft-shell turtle (Rafetus swinhoei), the world’s rarest freshwater turtle, hitting the pages of the New York Times this month, it would appear scientists aren’t the only ones tuning in to see what fate his in store for a species for which there are only four individuals known to exist in the wild or captivity today.

Swinhoe’s softshell turtle has long been famous for it role in Vietnamese legend as the fabled Sword Lake Turtle, which inhabits Hoàn Kiếm Lake (“The Lake of the Returned Sword”) in Hanoi, Vietnam. But of the handful of Swinhoe’s softshell turtles known to scientists to exist in the wild or captivity in recent years, five have died since the 1990s, leaving only four remaining: one in Hoàn Kiếm Lake, one in the wild in Đồng Mỏ Lake west of Hanoi, and two in captivity, the latter now both part of the Suzhou Zoo’s captive breeding program.

Since 2008, when the Changsha Zoo’s female, “China Girl,” was relocated to Suzhou, scientists at Suzhou Zoo have undertaken a captive breeding program with their older male turtle. But despite repeated bouts of courtship displays and mating between the pair in the years since, the resulting eggs have failed to hatch. Remediative actions to date, including steps to improve their diet by constructing a glass wall to prevent visitors from tossing junk food into their inclosure, provisioning the pair with a more natural diet (e.g. whole shrimp, freshwater crayfish, fishes, freshwater snails, frogs, quail, pigeons), and redesigning their enclosure to allow the pair more time together, have proven unsuccessful.

After the Suzhou Zoo’s captive breeding program reported last fall that their male may be infertile, the future of the program and the species were both at risk. In a move that lets slip their growing concern for the species’ survival, researchers this spring attempted what had until recently been considered by stakeholders too controversial – artificial insemination.

On May 6th, herpetologists Gerald Kuchling with the Turtle Survival Alliance and Lu Shunqing with the Wildlife Conservation Society’s China branch, together with a team of specialists, anesthetized the Suzhou male and – with a stack of car tires as an examination table – used an electrical probe to extract sperm. In doing so, the team was also able to closely examine the male’s penis and found that it had been mangled, possibly during an ill-fated encounter with a second captive male several years ago.

Although the sperm showed low motility, they were otherwise deemed viable and were deposited in the sedated female’s oviducts. However, with so little known about the reproductive physiology of turtles and tortoises, much less the Swinhoe’s softshell turtle, only time will tell whether this year’s attempt proves successful.

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Swinhoe’s Softshell Turtle: Captive Breeding Program Update

The annals and magazine of natural history : zoology, botany, anGiven that there are only four of the world’s rarest freshwater turtle, Swinhoe’s soft-shell turtle’s (Rafetus swinhoei), known to exist in the wild or captivity today, the news this fall from the Suzhou Zoo’s captive breeding program that their male may be infertile has forced researchers to reconsider the program’s future.

Not only is it the rarest freshwater turtle species, Swinhoe’s softshell turtle is also famous for it role in Vietnamese legend as the fabled Sword Lake Turtle, which inhabits Hoàn Kiếm Lake (“The Lake of the Returned Sword”) in Hanoi, Vietnam. But of the handful of Swinhoe’s softshell turtles known to scientists to exist in the wild or captivity in recent years, five have died since the 1990s, leaving only four remaining: one in Hoàn Kiếm Lake, one in the wild in Đồng Mỏ Lake west of Hanoi, and two in captivity, the latter now both part of the Suzhou Zoo’s captive breeding program.

Since 2008, when the Changsha Zoo’s female, “China Girl,” was relocated to Suzhou, scientists at Suzhou Zoo have undertaken a captive breeding program with their older male turtle. But despite repeated bouts of courtship displays and mating between the pair in the years since, the resulting eggs – this year’s, too – have failed to hatch. Remediative actions to date, including steps to improve their diet by constructing a glass wall to prevent visitors from tossing junk food into their inclosure, provisioning the pair with a more natural diet (e.g. whole shrimp, freshwater crayfish, fishes, freshwater snails, frogs, quail, pigeons), and redesigning their enclosure to allow the pair more time together, have proven unsuccessful.

This fall with the support of the Turtle Survival Alliance, Kaitlin Croyle, a research assistant with the San Diego Zoo’s Institute for Conservation Research, visited the Suzhou Zoo to remove the yolk membranes of fresh laid eggs and examine them microscopically for sperm, a technique known as ovo sperm detection. Croyle was unable to detect sperm, confirming what many have long suspected, that the male is likely infertile.

Despite this setback, with the permission of Chinese officials Rafetus stakeholders are instead exploring the option of artificial insemination. But to do so, they need a new male Swinhoe’s softshell turtle. To this end, herpetologist Gerald Kuchling is following up on anecdotal observations of possible Swinhoe’s in the Red River in Yunnan Province, China. There, Dr. Kuchling and Dr. Rao Dingqi at the Kunming Institute of Zoology are using collapsible “cathedral traps” designed to trap deep waters, but which are also buoyant enough to allow turtles to surface and breath. Unfortunately, scientists aren’t the only ones interested in catching Swinhoe’s soft-shell turtles. Locals and fisherman see the turtles as food. According to an August 2014 update by Kuchling in the Turtle Survival Alliance’s magazine, Turtle Survival, “There is a real danger that the last wild R. swinhoei in China could end up at a banquet rather than in a breeding program.”

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Chelonian Conservation and Biology: Surveying for Swinhoe’s Softshell Turtle

In recent years, the Swinhoei’s softshell turtle (Rafetus swinhoei) has risen to fame in part because of its renown as the rarest freshwater turtle in the world (there are only four Swinhoe’s softshell turtles known to exist in the wild or captivity today), not to mention its prominent role as the famed Sword Lake Turtle of Vietnamese legend. Writing in the July 2013 issue of Chelonian Conservation and Biology, a team of Chinese researchers published the results of a four-year survey of villagers living along the Upper Red River, China, to determine the historical distribution of the Swinhoe’s softshell turtle and characterize suitable habitat where conservation efforts should be focused.

Following previous investigations that have narrowed the historical range of the species to the Song Hong (Red River) drainage in eastern China and northern Vietnam, the lower Yangtze (Yangtze River) drainage in eastern China, and the Song Ma (Ma River) drainage in northern Vietnam, the researchers concentrated their survey effort within the Upper Red River, where the present-day range of this giant softshell turtle is thought to be restricted today. Through questionnaires and oral interviews, which included testing interviewees’ abilities to positively identify local turtle species, the researchers canvassed more than 1,000 college students, fishery and wildlife managers, fishermen, turtle farmers, traders, restaurant keepers, and education/government officials across 38 counties, 3 provinces, and 82 communities (from towns to villages).

In general, the researchers found that the younger respondents (i.e. college students) knew little of any giant softshell turtles, while Dai/Thai villagers along the Red River and its tributaries had longer memories of a turtle they called either dao or wu gui (“black hardshell turtle”) or hua tou mei (“spotted head turtle”), all of which were positively identified as Swinhoe’s softshell turtles based on careful descriptions of the turtles and the inspection of skeletal remains. Following the intense pressures of commercial fisheries for softshell turtles in the region, by the late 1990s, specimens tentatively identified from photographs as Swinhoei’s softshell turtles caught using rolling-hook and electroshock fishing had become increasingly rare.

Through a comparison of habitat characteristics between the 33 documented capture/witness locations and 33 random contrasting plots using Google Earth, the researchers were able to characterize those characteristics that appeared to favor Swinhoe’s softshell turtle presence. These features include sandbars, necessary for basking and nesting, and tributary/main river confluences, which provide abundant food and create deep water as well as sandbars. The researchers also addressed the influence dams may have on surviving indivuals, citing the deleterious effects of reduced flows, habitat and population fragmentation, anomalous floods, lower water temperatures, and sandbar degradation. Sadly, the researchers note that of the 33 capture/witness locations, 29 are subject to flood following the erection of five dams slated for construction. The remaining four sites are at the mercy of a sixth proposed dam that, if constructed, could remove the last remaining high priority habitat suitable for Swinhoe’s softshell turtle.

Full Citation: Wang Jian, Shi Hai-Tao, Wen Cheng, and Han Lian-Xian. 2013. Habitat Selection and Conservation Suggestions for the Yangtze Giant Softshell Turtle (Rafetus swinhoei) in the Upper Red River, China. Chelonian Conservation and Biology: July 2013, Vol. 12, No. 1, pp. 177-184.

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