ST. LOUIS — The Saint Louis Zoo announced Thursday that one of its oldest animals had died.

Othello, a centenarian Aldabra giant tortoise, was humanely euthanized on Tuesday due to declining health from a gastrointestinal issue, zoo staff said. While the zoo didn’t know his exact age, experts estimate he was well over 100 years old at the time of his death. The tortoises take several decades to reach full size, and Othello arrived in the U.S. as a mature adult in 1938.

Staff said Othello was beloved by both zoo guests and employees during the 20 years since his arrival in 2004.

“He had a warm, engaging nature and regularly sought out interactions with people,” the Zoo said. “Othello was a guest favorite during our public tortoise tours, often delighting visitors by eagerly accepting carrots—one of his favorite treats. He was also known to recognize his keepers, frequently seeking them out for attention. Keepers always readily reciprocated and loved spending time with him, especially when he stretched out his neck for gentle scratches.”

Othello served as a conservation ambassador for his species, which is considered vulnerable to extinction and is among the last species of giant tortoise still on Earth, the zoo said. His long life brought awareness to the plight of his species to millions.

Another Aldabra giant tortoise named Ray joined the zoo with Othello in 2004. Ray still lives at the zoo and can be seen by guests in the zoo’s Historic Hill zone.

“Thank you to all the keepers, staff, volunteers and guests who knew and loved Othello over the years,” the Zoo said. “He was a beautiful, old soul who reached millions of people, and he will be missed terribly.”