The Phoenix Zoo’s sole adult male lion and the father of newly born cubs has died.

The 8-year-old African lion, Boboo (pronounced Bah-boo), was humanely euthanized Friday morning after the zoo’s veterinary team found an aggressive form of cancer affecting his kidneys and spleen, according to a statement from the organization.

“He was well loved by his keepers, Zoo staff, and guests, and the Zoo will certainly be quieter without his roars and calls,” read the Facebook post.

Part of the Species Survival Plan, a breeding and transfer program that is part of the nonprofit Association of Zoos and Aquariums, Boboo recently sired 6-year-old Phoenix Zoo lioness Zuri’s’ two cubs. Born June 3, the cubs are the first born at the zoo since 1976. Their sexes have not yet been determined as they bond with Zuri in their den, according to zoo spokeswoman Linda Hardwick.

“This has been a time of immense sadness, but also great joy as Zuri and her two cubs are doing very well and exceeding expectations with their growth,” read the statement, adding Boboo’s “legacy will live on.”

Arriving March 12, 2019, in Phoenix from the Columbus Zoo at 412 pounds, Boboo was expected to start his own pride here. He was born to Tomo and Asali, and their other son, Kitambi, resided at the Phoenix Zoo before his 2018 death from what the zoo said was a “severe systemic infection.” Boboo also had a half-brother, Donovan, and three sisters from his litter, while he was at the Columbus Zoo.

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The zoo’s statement Saturday noted an annual exam on Boboo in May revealed no signs of illness. However, the statement added that Boboo suffered rapid weight loss, progressive lethargy, had an intermittent interest in food and was not responding to medical treatment.

In addition to Zuri and the cubs, according to Hardwick, Phoenix Zoo’s surviving lions include the lioness mother’s sister, Kamara.

This article originally appeared on Arizona Republic: Boboo, the Phoenix Zoo’s 8-year-old male African lion, dies