Dolphin Oki-chan Dies, Lived for Half a Century at Okinawa Churaumi Aquarium

The Yomiuri Shimbun

11:30 JST, December 3, 2025

A female bottlenose dolphin named Oki-chan, estimated at 52 years old, at the Okinawa Churaumi Aquarium in Motobu, Okinawa Prefecture, has died. The Okinawa Commemorative National Government Park (Ocean Expo Park), where the aquarium is located, announced Tuesday.

Oki-chan performed in dolphin shows at the aquarium for half a century since the 1975 Okinawa International Ocean Exposition. Alongside the male dolphin “Muku,” also kept since that time and estimated at 54 years old, she held the world record for the longest-lived kept dolphin.

According to the Okinawa Churaumi Aquarium, Oki-chan had been unwell since this summer, undergoing treatment and recuperation. She had not appeared in shows since October. The cause of death is believed to be diseases associated with declining physical function due to old age.