POWELL, Ohio (AP) — The Columbus Zoo and Aquarium in Ohio says Tomo, the zoo’s 15-year-old male African lion, has died.

Zoo officials said in a release that Tomo was euthanized Wednesday and that the veterinary staff had been treating him for age-related issues.

The lion came to the Columbus Zoo in 2006 from the San Diego Zoo as part of a breeding recommendation from the Association of Zoos and Aquariums’ African Lion Species Survival Plan. He fathered three litters while in Ohio and was a grandfather of 11 and great-grandfather of five.

African lions were once common throughout Africa, but their population has decreased dramatically over the last two decades because of the loss of habitat and indiscriminate killing.