The nation's oldest captive tiger has died of natural causes at an animal park at the age of 22, or equivalent to more than 90 human years, a park official said.

The female tiger, who was called "Meru," was born in May 1992 at the Akiyoshidai Safari Land in Mine, Yamaguchi Prefecture. Meru was known for her easy-going nature, park officials said Sunday.

The tiger died Friday after losing her appetite late Thursday afternoon.

"She was a very beautiful tiger and I thought she would live much longer. Now, I want to tell her that she did a good job and that I thank her," Yusuke Ikebe, head of the park, said.