Shi took good care of Basi for 27 years, especially during the panda's recovery from high blood pressure and cataract surgery.

The average lifespan of wild pandas is 15 years, while those in captivity usually live longer due to better nutrition and living conditions.

Experts believe the fact that Basi had such longevity while living in in Fuzhou, a very different place from a panda's natural habitat, has important scientific research value.

Fuzhou is very hot in summer. The Strait Panda Research and Exchange Center provides air-conditioning and ice to cool the pandas' living environment.

Chen said the center had invested 20 million yuan (3 million US dollars) to build a summer resort for pandas in Guling Hill in Fuzhou, where the average summer temperature is less than 30 degrees Celsius.

"But Basi had been too old to move. She did not go to the resort this summer," Chen said.

"Rest in peace. You will become another legend in another world," said one post left on Weibo, a Twitter-like service.

"Wish you well in the Panda Planet," another Weibo user said.

Basi died without ever breeding.

Very low birthrates have been one of the major factors threatening the survival of the giant pandas, as is habitat loss, though the species was downgraded from "endangered" to "vulnerable" by the International Union for Conservation of Nature in September last year, thanks to protection efforts by Chinese scientists.

Giant pandas live mainly in the mountains of Sichuan and neighboring Shaanxi and Gansu provinces.

The number of pandas living in the wild was fewer than 2,000, and around 400 were living in captivity as of the end of 2013, according to data from China's State Forestry Administration.