The Turtle Survival Alliance (TSA), San Diego Zoo Global and WCS's Bronx Zoo announced today that working in conjunction with Changsha Zoo, Suzhou Zoo and the China Zoo Association, a female Yangtze giant softshell turtle (Rafetus swinhoei) -- potentially the last female of her species -- has been artificially inseminated. The procedure, which brought together top scientists from China, Australia and the United States, provides a ray of hope in a continuing effort to save the world's most endangered turtle.
There are four living Yangtze giant softshell turtles remaining in existence -- two in Vietnam (both thought to be males) and two in China at the Suzhou Zoo (a male and female). The male and female -- both believed to be greater than 100 years of age -- were brought together in 2008 as part of a captive breeding program initiated by TSA and the WCS (Wildlife Conservation Society) China program. The female was transported from the Changsha Zoo to the Suzhou Zoo through the efforts of four partners (Changsha Zoo, Suzhou Zoo, TSA, and WCS).
WCS China Reptile Program Director and coordinator of the Rafetus swinhoei breeding program, Dr. Lu Shunqing, mediated the program agreement among the partners and has coordinated the program during the past 8 years.
"It now appears that artificial insemination is the only possible option for the pair of Rafetus swinhoei in Suzhou Zoo to reproduce successfully," said Dr.Lu Shunqing. "The fate of the most endangered softshell turtle of the world is now in the balance."
Though the two turtles have before displayed courting behavior, eggs laid by the female have been infertile.
"We had to find out if the last known male in China no longer produces viable sperm due to old age or an inability to inseminate the female," said Dr. Gerald Kuchling, organizer of the artificial insemination effort and Rafetus breeding program leader for the TSA.
To determine the cause of the infertility, Suzhou Zoo, Changsha Zoo, and the China Zoo Association requested TSA assemble a team of scientists to conduct a reproductive evaluation of the male, collect semen, determine if he had viable sperm, and, if viable sperm could be demonstrated, artificially inseminate the female.
"At first we tried semen collection through manual stimulation and the use of a vibrator, but as previously found in another softshell turtle, the only way was through sedation of the male and electro-ejaculation -- risky procedures due to his old age," Dr.Kuchling said.
During the process, the male was determined to have damaged sex organs, perhaps due to a fight with another male decades ago. For this reason, the scientists believe the male incapable of inseminating the female, and therefore, fertilizing the eggs.
Dr. Barbara Durrant, Director of Reproductive Physiology at the San Diego Zoo Institute for Conservation Research said, "Normal semen parameters for Rafetus are unknown as this was the first attempt to collect and examine sperm from this species. The semen evaluation revealed that approximately half of the sperm were motile." Based on the results, it was determined the female could be artificially inseminated.
This attempt marks the first time artificial insemination has been tried with any softshell turtle species and based on results of insemination with other turtles, the odds are not good for success. With natural breeding unsuccessful however, the scientists felt it was time to explore this option. Both turtles recovered from the procedure in good condition.
"The attempts to breed this critically endangered species, and overcome obstacles to natural breeding by this global consortium of experts is a great example of international cooperation to save endangered species," said WCS Chief Veterinarian and Bronx-Zoo based Director of Zoological Health Dr. Paul P. Calle, who worked with Chinese veterinarians on the delicate sedation process. "We are grateful to our Chinese partners at the Suzhou Zoo, Changsha Zoo, and the China Zoo Association for inviting us to work with them in our collective attempt to save this species. "
"This was a great exploration to advance the conservation of Rafetus swinhoei, however, we cannot yet determine if the exploration was successful or not," said Director Chen Daqing of Suzhou Zoo. The female will lay the eggs in a few weeks and in a couple of weeks after that, the scientists will know if the eggs are fertile.
Listed on the International Union for the Conservation of Nature's Red List, the Yangtze giant softshell turtle is the most critically endangered turtle in the world. Its status in the wild has long been recognized as grim, but extinction risk now is believed higher than ever. Much of its demise has been attributed to over-harvesting and habitat degradation.
Fort Worth Zoo Biologist and TSA President Rick Hudson said, "The conservation world will once again be holding its collective breath until we know if this was successful. The optimism we felt back in 2008 when the pair was mating and laying eggs has slowly faded as reality sank in that this pair would not breed without intervention."
"This autumn, the female Rafetus swinhoei will be moved back to Changsha Zoo. We hope some children move together with her," said Vice Director Yan Xiahui of Changsha Zoo.
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