The World’s Oldest Koi Fish Died At 226 Years Old

• The average life span of a scarlet-colored koi carp is around 40 years old.
• Born in 1751 in the middle of the Tokugawa era in Japan, Hanako became a story of great interest when her last owner Dr. Komei Koshihara spoke nationally over Nippon Hoso Kyokai radio station in 1966.
• The age of the fish can be determined by counting the rings of growth on its scales. Two of Hanako’s scales had been extracted and analyzed for two months.

Hanako is believed to be the oldest living koi fish ever – she managed to reach an astounding 226 years before she died in 1977. The average life span of a scarlet-colored koi carp is around 40 years old.

Born in 1751 in the middle of the Tokugawa era in Japan, Hanako became a story of great interest when her last owner Dr. Komei Koshihara spoke nationally over Nippon Hoso Kyokai radio station in 1966. He revealed that Hanako’s age was verified by professor Masayoshi Hiro, who was working at the Laboratory of Animal Science of the Nagoya Women’s College.

The age of the fish can be determined by counting the rings of growth on its scales. Two of Hanako’s scales had been extracted and analyzed for two months.

Koshihara said that the fish was “still in perfect condition and swimming about majestically in a quiet ravine descending Mt. Ontake in a short distance.”

“She weighs 7.5 kilograms and is 70 centimeters in length.”

He revealed during the broadcast that he and Hanako are dearest friends and will come swimming to his feet when he calls her name. The fish also looked “quite delighted” whenever he pats her lightly on the head. He said he also takes her out of the water and embrace her.

Koshihara explained that telling the age of the fish requires “the aid of a specialist” and a “microscope”.

“As a tree trunk has its annual rings, so a fish has its annual rings on its scales, and we only have to count them to know the age of a fish,” he said.

Although he was hesitant to take a scale off Hanako’s body, he did it anyway to know her age. Using a strong tweezer, he pulled out two scales from different parts of her body and gave them to Professor Hiro to examine.

He explained how the fish came into his possession.

“My grandmother on the maternal side […] is said to have been told by her mother-in-law, ‘When I was married into this family, my mother-in-law said to me, “That carp has been handed down to us from olden times; you must take good care of it.”