Chinese internet users are mourning Peng Peng the panda which died on Thursday night at the age of 18. Peng Peng passed away at the China Conservation and Research Centre for the Giant Panda in Sichuan province, where it lived for most of its life and spent six years being treated for eyesight problems. Peng Peng was born in September 1999, one of the many sons of the renowned sire Pan Pan, and lived to be the panda equivalent of 50 years old, according to the news portal scol.com. Peng Peng had been receiving special care since 2011 because of cataract-related eyesight problems. But late last month, the panda showed symptoms that suggested it had been suffering from seizures. It later was diagnosed with encephalitis, and its appetite became poor. On December 7, Peng Peng fell unconscious and after a series of exams vets confirmed that the panda had bleeding on the brain. Peng Peng died after several days of treatment despite the efforts of medical staff to save it. Rare images show panda trying to seize territory in northwest China Peng Peng was the son of Pan Pan, one of the longest lived male pandas. Although pandas often struggle to conceive, Pan Pan had left more than 130 descendants – around a quarter of the current captive population – before its death last year at the age of 31. Peng Peng’s body will be used for pathological study, the centre said. It had not fathered any offspring. On China’s social media, internet users expressed their sadness over the loss of Peng Peng. “We lost another national treasure on the earth, but the heavens will have another cutie,” one Weibo user wrote. Chinese company uses giant panda poop to make ‘luxury’ tissues “I hope you can enjoy yourself in heaven and see many beautiful scenes that you couldn’t see on the earth,” another microblogger wrote. “Please come back to be our national treasure in your next life,” a third wrote.