Koi are large, colorful freshwater fish that are a symbol of beauty, tranquility, and longevity in many cultures, particularly in Japan where they originated. They typically kept in outdoor ponds due to their size, as they can grow up to 3 feet (90 cm) long in ideal conditions. They are hardy and can live for several decades, with some koi living over 100 years. Their longevity and size make them more than just fish; they become long-term companions and a living part of the garden or landscape. Koi are social and can be kept in groups, where they often display gentle and curious behavior, even becoming tame enough to eat from their owner’s hand.