In short, don't make your koi fish live in cramped quarters, and plan on having a high-quality koi pond by the time they're fully grown. If you're looking for a pet with longevity, the koi might ...

Here are some fascinating pet fish that can live for many years. Some are less conventional than others, but they’re all incredible animals! 1. Koi Can Live More Than 30 Years Koi carp are one ...

Among the most difficult to save are those that live in water. David and Jane Pierce have owned — and loved — these koi fish for 25 years.Credit...Stella Kalinina for The New York Times ...