The red koi fish Hanako lived from about 1751 to July 7, 1977. During that amazing time, Hanako, whose Japanese name means “flower girl” or “maid,” was owned by several people, with Dr. Komei Koshihara being the last.
The scales on her body told us how old she was.
From what The Guardian says:
“The age of a fish is calculated in much the same way as one works out the age of a tree by counting its rings; most fish have growth rings on their scales known as annuli. This technique was used to estimate the age of Hanako, meaning “flower maid”, the world’s oldest koi carp, who died in 1977 at the age of 226 years.” [source]
This picture shows Hanako in 1966. She was 70 cm (27.5 inches) long and weighed 7.5 kg (16.5 lbs). It is known that she is the oldest koi fish ever. [source]
Koi fish have one of the longest bodies on Earth, along with whales, tortoises, and tuataras. Based on Fish Laboratory:
“It is quite common to witness a koi that is over a century old in Japan. This is one of the reasons why koi fish have gained so much admiration in Japan and the rest of the world as well.
Environmental factors that contribute to a long lifespan are clean water, nutritionally balanced fish feed, and long cold winters. The cold season will slow down the koi’s metabolism drastically. During this period, the fish may eat very little to none.” [source]
With tweezers, two scales were removed from different parts of her body. Over the course of two months, professor Masayoshi Hiro of the Laboratory of Animal Science at Nagoya Women’s University carefully looked at each scale’s growth rings.
On May 25, 1966, Dr. Komei Koshihara told the story of Hanako on the Nippon Hoso Kyokai Radio Station, which was heard by everyone in Japan. He said that the koi fish came from his grandma on his mom’s side, who had gotten it from someone in “olden times.” Dr. Koshihara said that Hanako was his best friend. [source]
