(AP) -- A Tasmanian devil named Cedric, once thought to be immune to a contagious facial cancer threatening the iconic creatures with extinction, has been euthanized after succumbing to the disease, researchers said Wednesday.
The death of the devil - previously heralded as a possible key to saving the species - is another blow for scientists struggling to stop the rapid spread of the cancer, which is transmitted when the furry black marsupials bite each other.
"It was very disappointing indeed," said scientist Alex Kreiss of the Menzies Research Institute in Hobart, Tasmania, which has led the studies on Cedric. "It's just made us more determined to keep the research going."
The Tasmanian devil population has plummeted by 70 percent since Devil Facial Tumor Disease was first discovered in 1996. The snarling, fox-sized creatures - made famous by their Looney Tunes cartoon namesake Taz - don't exist in the wild outside Tasmania, an island state south of the Australian mainland.
In 2007, Menzies researchers injected Cedric and his half brother Clinky with facial cancer cells. Clinky developed the disease, but Cedric showed an immune response and grew no tumors - giving researchers hope that he could help them create a vaccine.
But in late 2008, Cedric developed two small facial tumors after being injected with a different strain of the cancer, which causes grotesque facial growths that eventually grow so large, it becomes impossible for the devils to eat. Current estimates suggest the species could be extinct within 25 years due to the prolific spread of the cancer.
Researchers removed the tumors, and Cedric appeared to be rallying. But X-rays taken two weeks ago showed the cancer had spread to the 5-year-old's lungs, Kreiss said. Tests confirmed the lung tumors were a result of facial tumor disease.
Surgery to remove the lung tumors was not possible, chemotherapy wouldn't have worked and researchers didn't want the animal to suffer, Kreiss said.
"We had to decide to euthanize him before he deteriorated," said Kreiss, who has worked with Cedric for years. "It was a really hard decision.
The scientists plan to soldier on in their quest to develop a vaccine, Kreiss said. There are also several other projects under way to help stave off extinction: Australian zoos have bred around 280 disease-free devils as insurance populations, and officials are conducting "suppression trials," where infected animals are trapped and removed.
The Menzies scientists buried Cedric, but have no plans to hold an official memorial for him, Kreiss said. Still, he hopes people will look to Cedric as a reminder of the hard work that must be done if the beloved creatures are to be saved.
"We always would like to remember Cedric as a symbol of the devils that are dying in the wild," Kreiss said.
Explore further: Can monogamy undermine intelligence?
More information: Save the Tasmanian Devil Program: http://www.tassiedevil.com.au/tasdevil.nsf