Blackie the hippo, who was believed to be about 59 years old, was euthanized in the off-exhibit Africa barn enclosure at the Cleveland Metroparks Zoo due to age-related ailments.
The animal retired from public life in 2008, and spent his remaining years in a "retirement villa" where he lived "contentedly eating copious amounts of produce and floating lazily in a pool he didn't have to share," said a release from the zoo.
"He lived a good long life," said zoo communications director Sue All. "It was a testament to the care he was given."
In fact, Blackie lived a remarkably long life: hippos usually live between 30 and 40 years in the wild, and a little longer in captivity. The zoo said it knows of no other male hippo to live so long.
Blackie was brought to Cleveland from Africa on a safari led by Vernon and Gordon Stouffer in 1955. Blackie was about a year old at the time, and was born in Tanzania.
The zoo said it had "no immediate plans" to replace Blackie.