Please visit our Sponsors

Related FAQs: Koi Selection,

Related Articles: Koi VarietiesKohaku, Taisho Sanke, Showa Sanke, Tancho Koi, Bekko Koi, Utsurimono Koi, Koromo Koi, Kin/Gin Rin Koi, Asagi/Shusui Koi, Kawarimono Koi, Hikarimuji Koi, Hikari Utsuri Koi, Hikarimoyo Koi, Doitsu Koi, Butterfly Koi,

Back to the Overview on Pond Livestocking 

/Aquatic Gardens, Design, Construction & Maintenance

Koi Selection

by Bob Fenner 

What makes a good koi?

Aquatic Gardens

Ponds, Streams, Waterfalls & Fountains:
Volume 1. Design & Construction
Volume 2. Maintenance, Stocking, Examples

V. 1 Print and eBook on Amazon
V. 2 Print and eBook on Amazon

by Robert (Bob) Fenner

Amongst all the kinds of ponds, water-lily, reflecting, chlorine-poisoned, "English", et al. there are none as industrious or popular as variants of "Japanese" koi ponds; to raise, keep, grow and show these "ornamental carp". Hence a treatment on how to go about selecting stock is warranted; in fact, much of what is offered here applies to all livestock, animal and plant.

There are several factors, relative and absolute to consider when selecting nishikigoi (Japanese ornamental carp, koi). Categories of health, variety, quality, and cost-reasonableness are some of the more important. This Section describes my opinions concerning what merits value in nishikigoi in general, and how to apply such knowledge to acquiring livestock.


First and foremost to consideration of whether to purchase is the physical well-being of the individual/s in mind. Check the stock for signs of infectious and parasitic disease. Holes, missing or poorly replaced scales, bent fin rays and curvatures of the spine, anomalies of the eyes call for disregarding the specimen.

Observe the Fish in Question Carefully!

  The new fish may result in the loss of other livestock. Ask about the fishes background. How long have the people had it? Was it dipped, quarantined, otherwise treated on arrival? What about the other fish in the system; how do they look? Prospective buys should be observed up close in a light colored container. Here I'd like to stress a point: nishikigoi should never be lifted from the system in a net into the air. The thrashing about damages the fish. They should instead be instead tipped gently into a pan-shaped container submerged partly in the system. If the individual is large and the handler skilled, the fish may be lifted from the system by hand. To repeat: only the smallest of individuals should be lifted from the water in a net.

What can you determine by watching the fish's behavior? Much. Koi are social creatures; avoid individuals off having "private" parties. Look and feel the fish's flesh. It should be firm, bilaterally symmetrical and adequately slimy. Be wary of a too-dry or dripping-mucus specimen; generally attributable to poor water quality. Which brings us to the next most important criterion:

Scrutinize the Source of Your Purchase

The physical plant should be neat and clean. There should be no dead or dying livestock with water confluent with the prospective purchase. How is their water quality? Ask questions regarding foods, feeding, their use of therapeutic agents. Are they knowledgeable, concerned for their livestock and your success? Remember, in my opinion, introduction of "problems" (mainly infectious and parasitic) are the second largest source of morbidity/mortality in the "koi" hobby (First is poor water quality). Hole in the side disease (ana aki, furunculosis), anchorworm, fish lice, bacterial and viral, worm and other crustacean diseases are spread-able by careless introduction of an infected specimen.

If the purchase is a new arrival and there is facility for doing so, put a "down-payment" on the fish and have them hold it for you for a couple of weeks. Standardized approaches to treatment systems and parasite prevention and treatment we'll cover in other forthcoming articles. The benefits and efficacy of prophylactic dips and quarantine cannot be overly promoted.

The Koi Themselves

After a clean prognosis has been determined for the fish in mind, comes an evaluation of it's aesthetic attributes. Here I'd like to trot out the usual apologia/explanation that passes for describing the wide range of difference of opinion over time and countries for what's valuable and not in a given individual, or classification of, koi. Yes, there are the typical vagaries of "beauty is in the eye..." subjective evaluations. Yes, there is no total consensus of how one given factor or set of factors "should" "always" be weighted against another. Yes, those Japanese and Chinese texts (not to mention those few in English) are difficult to acquire, fathom, are internally inconsistent and incomplete.

Too much of what passes as official "judging" is and has been a matter of "vocal tradition", i.e. not published or a matter of long-standing, ongoing tested and testable science.

All that being written and read, I will briefly try to explain how's and why's of criteria that are decided upon, my knowing of the same replete with allegory and judgment, and finally my version of what's important. You shall be, as you actually are, the final word in the validity and usefulness of such a schema.

When one attends, or better still, participates in one of the many annual koi shows that go on in most large cities in the so-called civilized world, you may notice the use of a scaled set of factors being applied by appointed judges to reach consensus as to what fish of what size and category ranks higher than the other. These judges are summoned from "other parts", don't or intellectually won't speak much of the native tongue, and are the deciding voice in the contest. The aforementioned "factors" include such notions as "figure, color, pattern, quality, elegance, character, personality (I'm not joking) imposing appearance..." without much offer of definition of terms. These "factors" and others are given something in the way of point status and the individual fish's scored and compared accordingly. Sound suitably vague and ambiguous to you? Me too.

After having been active in the hobby and trade for twenty five years in the U.S. and Japan, reading and writing extensively in the same, including the Zen Nippon Airinkai's Rinko Magazine, being involved with this Japanese influence and American equivalent's club of clubs organizations in promoting and developing koi club's and shows in Southern California, and dealing with the public's questions eight bizillion times on the subject, here is my edition of "How to Select Koi". Thank you for your patience.

In my opinion, there are four main criteria for evaluating nishikigoi:

1) Body Shape, conformation or the fancy name morphology,

Almost all Grand Champions and Runners up are females. Males are too skinny when large. Female (doitsu) scale-less Taisho Sanke

2) Intensity of color and pattern,

Color should be bright! Patterns tell a story. 

3) Distinctness of color and pattern, and

Note, no bleeding hi (red) or sumi (black) allowed!

4) Balance (distribution) of color and pattern.

This four step Kohaku shows good balance

Please allow me to explain first that all koi are the same species. Indeed, they're the same species as the common (food) carp, Cyprinus carpio found and cultured almost worldwide. There are several to twenty or more (100+?) described classifed varieties. These are defined by lineage, history, color, pattern, in honor of lines of emperors among other things. I could offer other pieces in this series for describing this artificial assemblege and the wherefores of what to look for, and even a vain attempt at why. For now, don't let the fancy names throw you, they will make sense.

1) Body Shape, Figure or Conformation:

Unlike goldfish and other ornamental varieties, all koi are intended to fit an "ideal" symmetry. This shape is somewhat sex and size dependent but can be learned with visual practice. It is a pleasing fusiform torpedo-form with an evenly tapering head. Many American-produced fish have a difficulty in being too pyxicephalic or blunt, box-headed. Almost all valuable fish of size (greater than 18") are females, the males being too tapered. Check it out, female koi are broader at the shoulders and further back through their flanks.

The paired fins, pelvic and pectorals must be of the same size and shape. They should show no evidence of being torn and healed unevenly and should be symmetrically branch-rayed. The remaining unpaired fins, dorsal, anal and caudal should be similarly arrayed and exhibit no trailing edges or elongations. A couple of comments here. There are such things as "butterfly" or "long-finned" varieties of koi. These sport mutations of nishikigoi do not enjoy any real position of worth in "legitimate" koi showing (yet). The other item I want to mention here is the abhorrent practice of "trimming" or surgically modifying a specimen for the purpose of sale or competition. This activity is not permanent and may be dangerous to the specimen, and is obvious to the learned eye.

Scale rows should be even and symmetrical per the variety.

Gin-Rin, Doitsu and other mirror or German-scaled derived varieties of nishikigoi must be compared with an unattainable "perfect" form for scalature. Replaced scales that are similar in shape, color, reflectivity and insertion from their originals need not disqualify a specimen from competition. One that is permanently scarred or missing from injury or disease may be.

2) Intensity of Color & Pattern

May seem easier to quantify and qualify than Elegance or Imposing Appearance: Red in all cases where defined in the variety should be bright, deep tomato, blood,... red. There are many types and equivalent terminology defining grades, tints and shades of red. Basically red is red, Ok? Okay. Or if you prefer, Hi ("Hee", Japanese) should be red. Similarly sumi (as in so "sue me") should be dark black, blacker the better. Whites should be snowy, not milky, alabaster white; metallics clean and shining bright.

By patterns we can mean several things in different varieties. For instance, Azuma (lightning) patterns were very popular twenty and more years ago in Kohaku (red and white) and Sanke (three <red/black/white>) varieties. Sometimes the number and shapes of "islands" (patches) of color and patterns is important and reflected in the naming and respective price and popularity. In one and two metallic colored varieties (Hikari Muji and Hikari Moyo) the colors must be bright and broadly uniform. In particular, "clearness" in the head color of koi is to be avoided.

3) Distinctness of Color and Pattern:

Again, pretty straight forward. Color margins should be distinct and sharp. Per the pattern for classification/variety the head, shoulder and tail area have specific criteria that you must be aware of when selecting koi.

Small, indefinite markings, particularly dark specks should be avoided.

4) Distribution of Color or Pattern:  

Draw an imaginary line down the midline of a koi from above and an intersecting cross line about it's middle. These four quadrants may allow you some perspective in considering balance of color and pattern. years back there were some specified mathematical magical starting and ending points for markings of "champion" koi; even allegorical stories said to be evidenced by some stated patterns. Nowadays, there is not such a strictly rigid system as before with allowance made for some placement of pattern in all four quadrants as mentioned above. The actual pattern is somewhat dependent on the size of the specimen with a large and powerful pattern being desired on large koi. To quote Grant Fujita, "Each pattern has to be clean, clear, and even. The pattern should not have any small white spots, or opening in the pattern."

A Final Note On the Above Four Factor Grading System:

All the above criteria are important to varying degrees for the various classifcations of varieties. Body conformation is a universally important characteristic, with the other factors being more and/or less so as accords whether they have distinct colors, patterns or distribution of the same. Remember, any of these grading schema are arbitrary and secondary to the overall health and your enjoyment/appreciation of your nishikigoi.

Other Important Facts Concerning Selection:There are many.

Colors, patterns, distribution, even body shape and definitely health can, might, do change with time and the influence of several contributing factors. A list of the more important developmental influences includes nutrition, infectious parasitic, nutritional and environmental disease.

"Environmental" involves the popular "water quality" dog & pony show of metabolite build-up, thermal stress, gas variables and on and on. For most of us mere mortals, designing, building and operating an optimized system, not over-crowded, with frequent, partial water changes, adequate, appropriate filtration, buying stock with enough genetic and developmental history...is enough.

Even in commercial establishments, there are given ponds that supplied with a random mix of fry and fed and otherwise treated similarly, result in koi with more certain types or intensities of colors or markings. You can buy an inexpensive small fish and have it (make it?) become a champion, and without too much effort, spend the big bucks and ruin a good fish through crowding/metabolite poisoning, poor nutrition, infectious or parasitic disease...


As a koi hobbyist, you will decide what type of quality and type of koi you're aiming for and invest your time in studying searching and building your system and collection accordingly. Show quality koi are expensive to outright purchase, but good to competitive quality fish need not be prohibitively so. In a well engineered system a good koi with potential can be improved into a winner.

If you are strongly interested in learning how to or actually going about collecting show quality nishikigoi I suggest becoming active in a local koi club, a national association like the ZNA or Associated Koi Clubs of America, and attend as many shows as you can "looking over the judges shoulder" to learn as much as you can. Some authors have suggested making drawings or taking photographs of your specimens as they age as a learning/historical tool; this is an excellent idea.

Literature Cited & Further Reading:

Cole, Peter. 1990. Koi; freshwater revival. FAMA 8/90.

Cole, Peter. 1991. A multitude of color. FAMA 5/91.

Fujita, Grant. 1992. The new way of selecting koi. Koi USA 11-12/92.

Gratzek, John G. & Emmett B. Shotts, Jr., 1991. The "Shotgun" Approach, How to Medicate Freshwater Tropical Fish. Pet Age Magazine, July, 1991.

Hansen, Galen. 1992. Goromo. Koi USA 11-12/92.

Kamihata, Shigezo. 1988. The evolution of nishikigoi, parts 1,2. Tropical Fish Hobbyist 6,7/88.

Koi USA. Official magazine of the Associated Koi Clubs of America. They have compilations of articles, slides tapes, directories.

Kuroki, Takeo. 1993-4, Classification of nishikigoi. TFH 7/93-5/94.

Murakawa, Toshio, 1985. Murakawa's Seminar No. 18 Conditions of Good Quality Colors. Rinko, ZNA 10/85. This publication is expensive, but definitely worthwhile. Available in English.

Poppe, Chuck. 1993. Ogon; hikarimono-hikarimujimono-ogon. Koi USA 11-12/93.

Quinn, John R. 1984. Those kaleidoscopic koi. TFH 7/84.

Tave, Douglas. 1989. Inheritance of scale pattern in koi. TFH 5/89.

Walker, Braz. 1973. Cyprinus carpio, a carp with many faces Tropical Fish Hobbyist 7/73.

Windsor, Dominic G.E., 1989. Selection of Nishikigoi. TFH 4/89.

Aquatic Gardens

Ponds, Streams, Waterfalls & Fountains:
Volume 1. Design & Construction
Volume 2. Maintenance, Stocking, Examples

V. 1 Print and eBook on Amazon
V. 2 Print and eBook on Amazon

by Robert (Bob) Fenner
Become a Sponsor Features:
Daily FAQs FW Daily FAQs SW Pix of the Day FW Pix of the Day New On WWM
Helpful Links Hobbyist Forum Calendars Admin Index Cover Images
Featured Sponsors: