Koi can live in aquariums until they are six inches in length, or about two years old. The most important considerations in tanking koi are the number of fish in the space and water quality conditions. More »

Koi can be kept in aquariums, but this isn't healthy for the fish if the aquarium isn't proportionate to their body size. Most adult koi live in outdoor ponds to accommodate their large size. More »

Exactly how much Koi fish cost depends on a number of factors, including the size and the specific breed of the fish. As of June 2014, a small, standard Koi fish costs as little as $4. Koi that are larger in size can cos... More »

Exactly how much Koi fish cost depends on a number of factors, including the size and the specific breed of the fish. As of June 2014, a small, standard Koi fish costs as little as $4. Koi that are larger in size can cos... More »

Koi can be kept in aquariums, but this isn't healthy for the fish if the aquarium isn't proportionate to their body size. Most adult koi live in outdoor ponds to accommodate their large size. More »

Koi live an average of 50 to 70 years, but can live over 200 years. The oldest koi on record is Hanako, a scarlet koi that died in 1977 at the age of 226. More »

Koi eggs hatch about three days after females lay them; in colder temperatures, the time can be as long as four days. They are laid in clutches that average 30,000 eggs, after which they are fertilized externally by the ... More »