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 »

Although both goldfish and koi are descended from the crucian carp, koi have feeler barbels and generally grow longer than goldfish. Goldfish have bigger fins and a more compressed body shape, while koi are longer and mo... More »

Fish lifespans can average anywhere from one year to 20 years. The lifespans of aquarium fish vary greatly depending on the species. 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 »

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 »

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 fish have a typical life span ranging from 50 to 70 years. There are authenticated cases, however, in which koi have lived over 200 years. More »