Buying koi from farmers breeders

I want to purchase some more koi for my pond as I haven’t bought any for a while. Normally I would go for Japanese koi but recently I’ve been wondering what the difference is between Japanese, Israeli and English koi?

At the moment I have all Japanese Sanke’s in my pond but I wanted to introduce a few different varieties and koi from different countries. The koi I have already weren’t cheap but that isn’t really the point. I know English and Israeli bred koi are supposed to be generally cheaper so there must be a reason for this.

So, what I’m asking for really is just some comparisons, and the benefits and pitfalls each different breeds may have?

I am tempted to give you a very short answer and that is to base your koi purchases on the strength of their physical beauty rather than their country of origin. Surely if you like the look of it, it is good enough to be kept in your own pond irrespective of where it was farmed.

I believe there is a degree of the ‘emperor’s new clothes’ associated with the purchase of koi, where the belief is that every single Japanese koi is excellent and of superior quality compared to koi from any other country. I have seen what I would describe as simply average (and at times below average) Japanese koi both in Japan and UK that I am sure would not have enjoyed a market following had they not be described as Japanese. In fact, I have even heard on more than one occasion dealers trying to sell their koi on the fact that they were Japanese rather than their physical appearance (which at the time, in my opinion was nothing special), implying that their origin should be considered of greater significance to the koi keeper that the koi’s quality.

And even though we can’t make any hard and fast rules about the quality of Japanese koi compared to koi from other origins, we can make some generalisations by saying that Japanese koi do offer us a higher quality than those of other origins. There are several reasons for the differences in quality, but other factors will also affect your decision when considering koi from of origins.

It’s in the genes.

The single most important factor which determines the quality of koi are the genes that the koi has inherited from its parents. As we know, koi are artificially selected ornamental carp whose genes have mutated to produce colourful freaks of nature. Given a chance, these unstable desirable physical attributes of colour, pattern, and skin quality would revert back to wild type (dull, unmarked carp) in only a few generations. It is the koi breeders’ mission to continue to work with the desirable (yet recessive) genes that his brood stock continue to yield to enhance further the desirable physical traits that we as koi keepers demand.

To achieve this relentless quest for better quality koi, koi breeders cross closely-related fish in an attempt to increase the frequency of the desirable and recessive genes, eventually leading to the creation of a bloodline with recognisable characteristics which may become the trademark of a specific breeder. Furthermore, to improve the quest for quality, koi breeders in Japan will often specialise in one or two closely related varieties, whose genes, broodstock and bloodlines they can concentrate on for generations.

Once you have met a number of top class Japanese koi breeders, you soon appreciate that they have committed themselves (and often their entire family) to a lifetime’s work in the perfection of a specific variety. You get the impression that they are in some way addicted to the treadmill of improving on the quality of last year’s harvest. Behind them, they have many generations of experience which they can’t afford to lose but must build upon – broodstock and bloodlines clients that the competition would die for.

This is largely why the Japanese consistently produce the best koi in the world. No other breeders have the experience, genetic heritage or way of life to be able to produce koi of the same quality. All other breeders are playing catch-up and because these improvements in koi quality can only generally be achieved by careful selection year after year it is unlikely that other sources of koi will ever reach that of Japan.

However, as I touched on earlier, Japan also has its own fair share of undesirable genes which continue to try to manifest themselves in certain breeder’s ponds as average quality koi. Just because a koi is Japanese does not mean that it will by rights be better than all koi from other origins across the world.

I have spent several years of my own life farming koi in the UK for a living and fully appreciate the challenges and limitations that can be encountered when trying to emulate the world leaders. I was fortunate enough to have show-winning brood stock and excellent spawning and rearing conditions and all bode well for some show quality offspring. Several different varieties were spawned (Shusui, kohaku, purachina) crossing apparently compatible brood fish which resulted in many hundreds of thousands of fry.

These were culled at an early age of a few weeks and again several weeks later. It wasn’t long before you could appreciate the range and complexity of genes involved in each variety. The purachinas bred relatively true, with the few imperfect ones being tinged with charcoal features which were easy to identify and cull. Then came the shusui of which a smaller proportion showed either recognisable pattern or scalation. Finally, the kohaku cross produced quite literally at the end of the first growing season only several handfuls of patterned kohaku (and Sanke).

Some of these patterns were unbalanced exhibiting orange pigment rather than red with a variation in body shapes and sizes. This brief foray in breeding koi in the UK showed me how far behind the Japanese professionals we really are, and that there is more to breeding good quality koi than starting off with good quality brood stock of individual merit. It was obvious that the more genetically complex the variety (as in the kohaku) the greater the challenge at producing high quality offspring.

The Japanese have had generations to find the pairings that work and the resources to continually re-test and trial new crosses. I would suggest that the quality of kohaku or go sanke that a country can produce could be used as the benchmark of how they are progressing in koi farming as a whole. We will see relatively good quality examples of the less complex varieties such as the ogons and shusui from around the world but only truly stunning examples of these and of the more complex varieties (go sanke) from Japan.

In order to make the UK koi farming enterprise viable, we decided to change our strategy from breeding true varieties to producing a colourful mixed bag of koi, which meant that there were fewer recognisable varieties but that less were culled and more went to market (the less demanding garden pond market).

Consequently the majority a UK-bred koi tend to exhibit the Heinz variety mix and will be priced accordingly. The Israelis farm koi on a similar basis but on a huge scale and throughout a very lengthy and favourable growing season. All these factors contribute to producing a wide range of koi of improving quality at a very competitive price.

Other factors to consider when comparing different origins of koi.

Transportation. Besides adding to the overall cost of koi, transportation also has some implications for the health of koi. With journey times of at least 24 hours door-to-door from Japan (slightly less from Israel) koi will inevitably experience a degree of stress during transportation. This will have to be addressed by your dealer who after a period of acclimatisation will then offer his rested koi for sale.

There are of course no such epic journeys required for UK koi, but you could argue, that if the koi are not of the same quality, is their relative stress-free status of any consequence?


More recently, it has been possible to purchase koi from Japan with a guaranteed provenance, stating which breeder farmed the koi. This not only tells us whether our koi have been produced by a show-winning breeder, but also gives us some idea as to how the pattern or colours will develop over time (depending on the bloodline). UK and Israeli koi do also offer a degree of traceability but with little consequence as to the finer details as to the quality of each koi concerned.


Israeli and Japanese koi farmers benefit from a warmer growing climate for their koi giving them a greater advantage over the UK farmers, enabling them to grow koi at phenomenal rates. This means they can offer us even larger koi than ever before. Koi reared overseas will have to undergo some degree of acclimatisation in the UK and may not ever enjoy the favourable warm conditions they were reared in overseas. UK breeders claim that as there is no change in temperature between fish farm, koi dealer and koi keeper then stress and acclimatisation will not be as big an issue for their koi.


This is a very topical factor when discussing the origins of koi, especially in the light of viral diseases such as KHV and antibiotic resistance. KHV is definitely confirmed in Israel and there is strong evidence that KHD is present in Japan. To keep a balanced view on this, only a very small minority of UK ponds that have stocked koi from either Japan or Israel over recent years have encountered the KHV problem. Nevertheless there is still a risk which every dealer should be open to discuss with every prospective koi customer. Historically, the intensive rearing practices of koi in Israel have been associated with the production of antibiotic-resistant bacteria that can prove to be vigilant upon outbreak, causing ulcers and other hard-to-treat problems. Even though this now appears to be under control it is a problem that UK reared koi have not encountered.

In summary

There are arguable cost and health benefits for buying UK-farmed koi with a higher quality koi being the exception rather than the rule. Israeli koi are also competitively priced with their overall quality greatly improving with exceptional individual koi running some typical Japanese koi close to the wire. However Japan is still the source for consistent top quality koi (even though there is such a thing as an average Japanese koi) and it enjoys many generations of breeders who specialise and excel in specific varieties. Nevertheless, I still believe that you must judge every koi you see on its physical merits and buy accordingly irrespective of its origin; you’re buying the koi for your pond, not for the koi’s origin.

Kill blanketweed and string algae.