SAN DIEGO (AP) — A 45-year-old male river hippopotamus named Otis and nicknamed the smiling hippo has died at the San Diego Zoo.
The San Diego Zoo Wildlife Alliance announced Monday that Otis had been under care for degenerative joint and spinal disease.
A decision to euthanize him was made last weekend when his condition declined significantly.
The San Diego Union-Tribune says Otis got his nickname in 2010 because of a viral photo taken by a zoo visitor that captured the hippo with his teeth displayed in what looked like a giant grin.
The 4,500-pound hippo was brought to San Diego from the Los Angeles Zoo 2009 to mate with a female.