Selecting the Right Koi

The success of your pond fish has a lot to do with where they come from. As always, we recommend buying your koi from your local reputable breeder rather than buying from a pet store or a national chain. Koi that come from a national chain usually endure hundreds, if not thousands of miles of travel before they reach their destination. Also, koi from national chains are exposed to many diseases and bacteria that attack their potentially weak immune systems. Furthermore, national chain koi usually aren’t fed or tracked for growth.

If you’re wondering what kind of koi you should purchase, you should have an open mind. There are many classifications of koi, with most of them classified by their colorations. To add further complexity, most classifications have a scaled (Gin Rin) and unscaled (Doitsu) version. Keep in mind, butterfly koi are beautiful, but many true koi breeders do not carry this breed. Butterly koi originated from inter-breeding with Indonesian carp and lack standard characteristics suitable for judging.

No matter what variation of koi you purchase, there are some characteristic signs you should look for in healthy robust fish. Also, you will have to consider your budget, since koi cost can run into thousands of dollars.

First, the koi you consider should be outgoing and swimming with the other fish. Naturally, koi are shy, but the healthiest koi actively swim with other fish and do not linger by themselves. You should also select koi that linger near the top of the water as you pass, so that you don’t get the shyest fish in the group! Also, the koi should swim smoothly and gently. If the koi twitches or jolts when it swims, or if the koi swims unevenly, it may have swim bladder problems (via bacterial infection).

Second, once you think you have a good fish, look carefully at its gills. Koi infected with gill flukes breathe through only one gill or have redness around their gills. If you see any of these signs, don’t buy this fish, and definitely don’t buy from that batch of fish! If one koi inside the group has gill flukes, then all of them have gill flukes.

Next, you should look at your koi’s body. The koi’s body should be thick, gently tapered and well defined. The scales on the koi should be flat with no visible lesions. The fins of your koi may have some minor damage if it’s recently been transported, or is kept in a crowded environment. This is acceptable as long as it’s minor and there’s no redness.

When buying koi, remember koi coloration changes as the koi matures. You may buy a koi with strong orange and black coloration, and in a few months, you may have a koi with red and orange. To avoid this, you can buy mature koi, but you’ll pay much more money. Another way to avoid this is to buy koi from a breeder who breeds the type of koi you want to buy. Keep in mind that this is the most expensive way to buy new stock, but well worth the money if you want a certain standard of koi.

Finally, you should look carefully at the proportion and balance of your koi. The fins should not look too big or too small. The belly of the koi should gently taper into the dorsal and pectoral part of the fish, and the back should be nice and smooth. The face of the fish should be imposing and well defined- not too short and not too long.

Many koi keepers choose to keep koi that are considered “imperfect” by koi standards. In the end, all that matters is your relationship and commitment to your fish. Many times, you find that the ugliest fish you own is the most personable and fun to keep! Unless you’re planning on professionally showing the fish at a convention, you should buy fish that appeal to you.