They Don’t All Have to Be Koi


It may seem like a novel concept, but not all the fish in your pond have to be koi. There are other pond fish out there that can bring joy and benefits to your water garden.  Some are beautiful, others – not so much. Nevertheless they all bring their unique characteristics to a water feature and will lend a little originality beyond the expected koi.


Shubunkins are a type of goldfish. They have a blunt head, can have either short or long fins, and they can grow to be about 14 to 16 inches long. They are undemanding fish with tough constitutions and friendly demeanors. They don’t tend to pick on each other and are customarily easy to hand train for feeding.

ShubunkinTypically, they are calico or multi-colored with a blend of blue, white, black, and red/orange. Some specimens have been spotted that were in fact mostly white, or mostly black, or mostly red, and of course, mostly blue. So, to an extent, it’s whatever your eye perceives as desirable, but also know this: The most desirable shubunkins are basically sky blue fish, “painted” to about 30 percent with brilliant red, and then highlighted with small accents of white and black. The more solid the black, the better, however the black can also be attractive when distributed solely as freckles.

For a while, there was a breeder in the North Eastern U.S. that hand-selected pure black and white shubunkins that had neither red nor blue in them. They were amazing but they were also as rare as hen’s teeth. The process was very laborious and yielded a small number of fish per pond, so these rarities were sold at a premium price. It isn’t certain whether their color “held” for their lifetime. Shubunkins are hardy fish for ponds in North America and are certainly durable for beginners. They are vulnerable to all of the same diseases as any other pond goldfish.

Mosquito FishMosquito Fish

Mosquito fish are from the gambusia group, known formally as Gambusia affinis. They are dull-colored, minnow-shaped fish that are closely related to guppies that are equally prolific (fast multiplying), giving birth to live young.

Their purpose in most ponds is simply to consume the immature forms of most insect creatures. In other words, they eat mosquito larvae, and that is why many people want them in their ponds. Here’s what you need to know. These mosquito fish are very, very hardy and they will survive exposure to most fish diseases with hardly any sign of illness. Therefore, you can buy very sick fish and not see signs of illness. For this reason, it is very important that you assume all mosquito fish to be parasite carriers that you quarantine and treat.


The plecostomus is a South American catfish that it is ugly-as-sin, but very hardy and are a great curative for string algae. One fish in a 1,000-gallon pond will eat all the string algae – that’s its favorite food. When you go to the pet shop, buy the largest plecostomus they have.

These should be pretty cheap, and here’s why; when the average tank hobbyist buys a “pleco” it’s five inches long or less. Within the year, it’s pushing 10 inches, so they trade it back to the pet shop for next to nothing, and the pet shop unloads them for a good deal to you. When you go in to the store, ask for a large, ‘trade-in’ plecostomus.

Two notes of caution. At night, in very small ponds, plecostomus will rasp on (suck on) the flanks of slow moving fish. If the pond is really small and the algae is all gone, they’ll suck on anything they can find, and damage some fish. I would not deploy a plecostomus in a pond that is less than 800 gallons. And if you do, know that the larger ones are less likely to rasp on the other fish than the smaller, more agile plecostomi. Any fish, that because of some internal pathology, is forced to live on the bottom, will be eaten by the plecostomus because it cannot get away. Healthy koi never have this problem.

Secondly, plecostomus will die when the water temperature drops to 55° F. Not 54° F … 55° F! In the fall of each year, you should anticipate this and pull the plecostomus out and put him in a plastic garbage pail with a little sponge filter for the winter. Feed him a disc of zucchini every couple days and he’ll hang in there ’til spring for redeployment in the pond.

So there you have it. There are other types of fish that can not only live happily in your water garden, but provide a benefit to it. So next time you’re out fish shopping, be sure to try a new kind of fish for your pond.