XI'AN -- The world's only brown-and-white panda died suddenly on Wednesday at a zoo in northwest China's Shaanxi Province, zoo officials announced on Thursday.

The 17-year-old male panda, Qin Qin, appeared normal on Tuesday, playing and eating congee and fruit, but was found dead at 5 a.m. on Wednesday morning.

Qin Qin may have died from a pulmonary edema. Medical experts will conduct a dissection examination to determine the exact cause of death.

Qin Qin could have lived longer, officials said.

In February, the Qinling Safari Park in Xi'an, capital of Shaanxi, issued an emergency "appeal" for a spouse for Qin Qin, hoping his descendants would inherit the gene of the rare brown-and-white pandas.

Keepers were ready to approve the transport of Qin Qin's sperm to another site for a distant impregnation but the project was never realized.

February-April is the sexually active period for giant pandas.

Qin Qin, who has never been "married", weighed 100 kg and stood172 cm on his back legs. He is the only child of "Wan Wan", a black-and-white male panda, and "Dan Dan", an authentic brown-and-white female panda.

The giant panda is one of the world's most endangered species and is found only in China. It is estimated that 1,590 giant pandas live in the wild in China. There were 183 pandas in captivity on the Chinese mainland at the end of 2005. A giant panda has a life expectancy of 30 to 40 years.