One of world's rarest soft-shell turtles dies, only three now survive
One of the last four surviving Yangtze giant soft-shell turtles died in east China's Suzhou Zoo on Saturday. 
The death of the female turtle came a day after zoo staffs made a last-ditch effort at artificial insemination, using semen from a male companion estimated to be more than 100 years old, according to the Suzhou Daily.
The other two surviving turtles are in Vietnam. Concerned over the extremely low number and turtle's inability to mate, the International Union for Conservation of Nature (IUCN) Red List declared it critically endangered in 2017.
Last year, the Asian Turtle Program confirmed a fourth individual of the species in Xuan Khanh Lake, near Vietnam's capital city Hanoi and Dong Mo lake.
The Shuzhou Zoo authorities tried unsuccessfully for several years to get the pair to mate and reproduce naturally. According to ATP, semen from the male was collected and surgically implanted into the female's oviduct.  
In order to revive the turtle's population, a team comprising of Chinese zoo officials, international experts, the Turtle Survival Alliance, and the Wildlife Conservation Society relocated the female turtle from Changsha Zoo to Suzhou Zoo, a decade back. 
The joint team tried to mate the two turtles, but the male turtle's penis was found to be damaged after a fierce duel with another male turtle. 
Experts decided to attempt artificial insemination to revive their population. In the last five years, several attempts were made to inseminate the female turtle artificially. 
The team will now conduct an autopsy to determine what caused the animal's death, the newspaper reported.
The Yangtze giant soft-shell turtle is the largest freshwater turtle in the world, growing to 100 cm long and weighing up to 100kg. 
The turtle species' primary habitat was the Yangtze River and China's other inland waterways.
(Top Image: Animal experts attempting artificial insemination in a female Yangtze giant soft-shell turtle at Suzhou Zoo in Suzhou, east China's Jiangsu Province, May 6, 2015 )