Koi Carp

Revised March 2022


Koi, or Nishikigoi as they were first called some 200 years ago when their cultivation began in Japan, are ornamental varieties of the Amur carp, Cyprinus rubrofuscus. For many decades they were considered to be color mutations derived from common carp but modern genetic analyses have shown this identification to be in error. The natural distribution of the true parental species includes temperate, cool-water regions of Asia and Europe. Ornamental koi carp are happy in warm water, but they can also tolerate cold winters, and this adaptability has led to their popularity among collectors and water garden enthusiasts throughout many parts of the world, including the U.S. The actual market for koi carp in the U.S. is difficult to determine due to the number of hobbyists and small-scale breeders who sell their product locally to one another and to pet shops. Other sales are targeted nation-wide via internet sites and auctions, trade magazines and specialty newsletters. These markets are often focused on very high-value fish, and many “sales” are on a cash basis or involve barters.

The lifespan of a koi carp may easily reach 20 to 25 years if properly cared for, and one specimen is on record as having lived over 200 years. Although selective breeding of carp originated in China, most of the development of ornamental strains has occurred in Japan during the past two centuries. Most modern techniques for koi production were also developed in Japan. Koi enthusiasts recognize a number of breeds or color variations (including 20 major categories), and organized exhibition shows similar to dog shows in which individual fish are judged best of breed and best of show have become common throughout the U.S. and many other countries.

Juvenile koi are also widely marketed in pet store chains, more or less as a commodity alongside fancy goldfish and other ornamental species. Water gardening has been one of the fastest growing gardening interests in the U.S. over the past several decades and as this hobby has grown in popularity demand for koi and fancy varieties of goldfish has increased rapidly.


According to the 2018 Census of Aquaculture, 149 farms across 29 states raised koi at that time, with total sales of $8.14 million. Florida ranked first in both number of farms (30) and total sales ($793,000), while Texas and Ohio ranked second and third in the number of farms (11 and 10 respectively) and Missouri and Ohio ranked second and third in total sales ($346,000 and $70,000 respectively). The nationwide average price per fish was reported as $6.89 at the farm gate, up from $4.56 in 2013.

Koi can be raised successfully across a wide range of environmental conditions. Temperatures between 81°F and 93°F promote optimal growth for young koi, while 68°F to 82°F is optimal for adults. The pH should remain between 6.8 and 7.5. Although koi are capable of surviving in warm waters with low oxygen, dissolved oxygen levels above 5.0 ppm are optimal. Spawning commences in early spring as water temperatures approach 63°F. A single female may produce up to 1,000,000 eggs, and breeders generally stock several males with one female of similar coloration, in the hopes of generating higher numbers of interesting or prized color combinations. Koi fry and fingerlings destined for high-end markets are usually stocked into earthen ponds to be grown to marketable size (anywhere from 1-2 inches to 1-2 feet in length). When the offspring are large enough to evaluate, the vast majority will be culled or sold into the pet trade, while only a few (typically only a few percent) will exhibit coloration worthy of a potential champion. Even when the business focus is on commodity-grade fingerlings substantial costs are usually associated with predator control on rearing ponds.

school of orange and white fishMarketing Considerations

Koi can be extremely high-value fish, with koi fanciers usually being equated with orchid collectors, dog or horse breeders, and similar specialists. The price differential, which depends on size and breeding condition, between standard-quality pond fish and prized show-quality fish is extreme. For example, one popular U.S. web site quotes prices for individual 3-inch to 4-inch fish at $4.00 to $24.00 and 23-inch to 24-inch fish at $660 to $3,000. A regional or national champion koi can be worth hundreds of thousands of dollars (or more) as breeding stock.

Depending on the target market (mass production of garden-pond koi, production of high-value fish from champion lines, or some combination of these extremes), a koi production facility can require moderate to high investment. If little culling is anticipated and fish will be mass produced, typical pond production facilities and methods suitable for regular carp can be adapted. Selective breeding and maintenance of high-value breeding stock generally relies on a combination of indoor and outdoor pond facilities. This requires much less land, but a significant investment in buildings and equipment.

Either approach requires a thorough understanding of potential markets. Since the end product is live fish, markets must be located within a reasonable distance to allow for safe transport and minimal stress upon delivery. Many pet stores and discount chains that carry pond-grade koi obtain their stock from large commercial suppliers, and breaking into these high-volume markets can be difficult or impossible. Local garden centers and independent pet shops may be the most logical place for potential producers to begin evaluating markets for their koi.

Seasonality of demand is an important consideration in koi production, because production management and finances must be based around this factor. As primarily a gardening/landscape product, demand for koi is typically highest during the spring, tapering off considerably over the rest of the year. Marketable fish during the time of peak demand will generally be 1+ years old, so they will represent a considerable investment. Markets must be available to accommodate your production when it is ready for harvest because maintaining the crop beyond a harvestable size requires excessive feed, labor and energy costs as well as unproductive use of facilities and capital. As a producer you will need to provide value through quality control and customer service, but your customers must also be willing to provide reliable outlets for your fish production when you need to move it.

Accurate and detailed cost projections are essential when establishing a koi farming business. Projected costs (variable, fixed, marketing and opportunity costs) must be compared to prevailing market prices for the sizes and quality of the fish you intend to produce. Keep in mind economies of scale – a smaller operation will have higher costs and will require small-volume markets that are willing and able to pay higher prices. This may require a focus on higher-quality fish, which will involve a higher investment in breeding stock and more labor and infrastructure to accommodate culling of sub-standard fingerlings. Input suppliers must be reliable and trustworthy, even when larger customers are competing with you. Consider your feed requirements – who will supply it, at what cost, and in what quantities will it be delivered? Where will your breeding stock come from? Again – how often, at what price and in what quantities? There are many inter-related factors that must be considered when developing a marketing plan for koi production.


Revised by C. Greg Lutz, Louisiana State University Agricultural Center