In the tranquil waters of a Japanese pond, a koi fish named Hanako lived through centuries of history. Born around 1751, long before the United States even became a nation, she swam peacefully through changing eras, passing from one generation to another. By the time she took her final swim on July 7, 1977, Hanako had lived an extraordinary 226 years, making her the oldest koi fish ever recorded.
But how did people know her true age? The answer lay within her very skin. Just as trees hold their years in the rings of their trunks, koi fish carry their age in the growth rings on their scales. In the 1960s, scientists removed two of Hanako’s scales and, after months of meticulous examination, confirmed that she had been alive for over two centuries.
Professor Masayoshi Hiro of Nagoya Women’s University led the analysis, carefully counting each microscopic ring. And when the results came in, they were nothing short of breathtaking.
The Secret to a Long Life
In Japan, koi fish are celebrated for their longevity, often living for decades. But Hanako was an anomaly—a fish whose lifespan rivaled even some of the longest-living creatures on Earth, such as tortoises and whales. Experts believe her pristine mountain pond, pure water, and harsh cold winters played a significant role in her survival. During winter, koi metabolism slows dramatically, allowing them to conserve energy and live longer.
A Cherished Companion
Hanako was not just a remarkable fish—she was deeply loved. Her last owner, Dr. Komei Koshihara, saw her as more than just a pet. To him, she was a lifelong friend, one that had been passed down through generations. In 1966, he shared Hanako’s story on Japan’s Nippon Hoso Kyokai Radio, where millions tuned in to hear about the incredible koi that had outlived emperors, wars, and generations of caretakers.
From a small pond in Japan to the history books of the world, Hanako’s life is a testament to resilience, care, and the mysteries of nature. A fish that swam for over two centuries, witnessing a world that changed beyond imagination—her legend lives on.
