What Fish Can Live With Koi in a Pond

If you are a first-time koi keeper like myself, you might be wondering which fish can live with koi in a pond. Well, I did my research and found out koi friendly pond mates. I also established those that you should not pair your koi with.

What Fish Can Live with Koi in A Pond

The fish that can live with koi in a pond are the following:

  • Sturgeon
  • Pleco
  • Tench
  • Golden Orfe
  • Shubunkins
  • Sarasas

Others are:

  • Goldfish
  • Catfish
  • Barbs
  • Barbel
  • Exotic goldfish
  • Chinese high-fin banded shark

Let us now look at these koi mates individually:


Acipenseridae is the scientific name for Sturgeon. Sturgeon refers to a fish family that constitutes 27 species.

Of these 27, four of them are almost getting extinct. Catching wild sturgeon, in many regions is illegal. The evolution of this fish dates to 245 million years back.

Over time, sturgeon can get big in weight and size. While aquarium or pond sturgeon can live peacefully and happily with koi, their movement can disturb your pond’s bottom.

For this reason, if you want to pair sturgeon with koi, make sure your pond is spacious enough to cater for their movement.


Hypostomus Plecostomus is the scientific name for Pleco. This tropical fish does well with koi.

Pleco, a hardy fish, suits well for aquarium and pond. This species is a darling of many fish keepers due to their attractive colors.

While Pleco are great koi mates, you need to be aware of two major problems associated with them. Primarily, they tend to latch with gradual-moving fish. Secondly, if you desire to pair them with koi, you must maintain a temperature of 55 degrees F as they cannot survive or thrive at low temperatures.


Tinca Tinca is the scientific name of Tench. They also go by the name doctor fish.

Wondering why they are referred to as doctor fish? Many people consider them to be physicians of fish.

Their body shape resembles that of doctors. This fish can reach up to 70 cm and weigh up to 7.5 kg.

Tench is a social and peaceful fish. Keeping them with koi does not create any challenges.

Due to their bottom-feeding nature, they tend to disturb the pond’s bottom part. Consequently, if your tank has fine sand at the bottom, you should avoid stocking this fish species.

Golden Orfe

Ileuciscus Idus is the scientific name for Golden Orfe. When a Golden Koi fish and Golden Orfe are placed together in a pond, differentiating the two is next to impossible.

Their body characteristics are almost similar. While they are bottom feeders, they can also swim inside the tank and get to the pond surface just like koi.

The fact that they are bottom feeders also goes miles to make sure they clean the ponds’ bottom area.

Another important attribute you need to learn about the Golden Orfe is that they are river fish. This fish species needs good water quality.

For that reason, if you put them with koi in a pond, you must maintain excellent water filtration and oxygenation.

It is also wise to keep not less than three in a group as they are very social.


Carassius auratus is the scientific name for goldfish. Goldfish stands out as the most common koi pond mate.

The characteristics of these two fish are the same. Goldfish happens to be the nearest to koi in terms of temperament and character.

In addition to both being cold-water fish, their diet is also the same. Another impressive attribute about Goldfish is the fact that they need less maintenance or care than koi.

What does this mean? It simply means that when you put them together in a pond, you will not give them extra attention or care.

When pairing koi with goldfish, you need to match them in terms of size. If you have small-sized goldfish, you cannot put them in a pond with large koi, as the latter will eat the former.

For this reason, you need to be careful and selective when putting koi and goldfish together.

Shubunkin and Comet Goldfish can be put with koi fish. These are strong and large enough to safely co-habit with koi. However, avoid putting a fancy little or baby goldfish in a pond.


Siluriformes is the scientific name of catfish. To many people, keeping catfish and koi might sound weird.

Of great importance to note is that countless catfish species can peaceful and safely co-exist with koi up to a certain age.

While catfish are tropical fish, they can live within a wide temperature range.

Some of the catfish variety that you can stock with koi include:

  • Iridescent shark
  • Columbian shark
  • Bumblebee catfish
  • Bandit Cory catfish

If you choose iridescent shark, ensure you pair them with only adult and large koi. If you pair a large iridescent shark with smaller fish, it will eat them.

Therefore, you need to exercise caution when pairing them.


As aforementioned, there is no harm in keeping shubunkins with koi. Shubunkins can mature or grow to 14 inches long.

For this reason, if you intend to put them in a pond, make sure that it is big enough to handle their big size. It needs to have 180-gallons of water if not more.

Many koi keepers love these species because of their striking colors. They spice up the color scheme of your pond. Often, shubunkins feature a calico appearance that incorporates sky blue, orange, black, red, and white colors.

The last thing you must do is worry about them as they can survive both cold winters and hot summers.

Because their character and temperament are almost the same as koi, the two can co-exist in a friendly way with koi.


Sarasas features a body shape that is like shubunkins. However, they do not grow to be as big.

Generally, their colors are vivid red, and white. Nonetheless, without exercising control when it comes to breeding, the fish population will ultimately revert to its roots thus making sure the pond has plenty of brown goldfish.


Barbus Tetrazona is Barb’s scientific name. Barbs originated from Indonesia and Sumatra.

These species feature a slender body. In terms of size, they can reach up to 3 inches.

Two best attributes of Barbs that make them great koi mates are their friendly and non-territorial nature.

Because of its small size, too much water is not necessary.

In terms of their lifespan, they can live for 6 years provided the water and food quality is high-quality. As they are omnivorous, their diet is like koi.

That means you do not have to buy different food for them.

In addition to being colorful fish, they are available in various colors. Since they are pretty much small, it is prudent to keep not less than five of them together.

Order your Barbs online here.


Barbus Barbus is Barbel’s scientific name. These Europe’s native can reach up to 4 feet. However, most of them are 40 inches.

Barbels can live up to 20 years. Due to their character similarity with koi fish, they make excellent koi pond mates.

On top of that, their diet and temperature requirements are almost the same.

Barbels are bottom feeders. For this reason, they help you maintain a clean pond or aquarium bottom by eating excess food or koi leftovers.

Because of their size, you must maintain them with adult-sized koi fish. Moreover, make sure that the tank size is large enough.

Finally, yet importantly, make sure that there is excellent water flow inside the pond.

Chinese High-fin Banded Shark

Myxocyrinus Asioticus is the scientific name for Chinese High-fin Banded Shark. These species are commonly found cypriniforme within the pet fish trade.

In your local store, they are sold alongside other cold-water fish such as goldfish and koi. As they mature, their coloration and black bands disappear. This happens as they reach an adult size of roughly 4 feet.

Of great importance to note is that high-fin sharks might have a challenging time competing with koi while feeding. They will not thrive or mature to adult size while depending on algae alone.

Exotic Goldfish

Some of the species that fall into this category are Ryukins, black moors, orandas, lion heads, and telescopes. Exotic goldfish are not as resilient as goldfish, meaning you must exercise more caution with them.

A circular bulbous abdomen characterizes this group of fish. This attribute is perhaps the reason they lack resilience.

Temperatures in the winter can upset the balance between their downward ballast, fat, and intestines. The winter temperatures can also be a contributing factor to their buoyant air bladder as it causes them to either flip over or worse still die.

By bringing them indoors during the cold months, you can help prevent this scenario from transpiring.

Questionable Koi Pond Mates

Some of the questionable koi pond mates include:

Channel Catfish

Ictalurus Punctatus is the scientific name for channel catfish. This New World catfish is popular in North America.

You can easily find their albino variants at your local fish store. The fact that it grows to roughly 4 – 5 feet in terms of length makes it very big to be put in the same pond as koi.

It can easily eat small to medium koi whole.

Amur Catfish

Silurus Asotus is the scientific name for Amur Catfish. This Japanese catfish species belongs to the Sheatfish group.

It features a motted white and black/brown. Although they do not grow to be as big as the European Catfish, the Amur grows up to 4 feet long.

They can eat small-medium koi. When it comes to larger koi, they may or may not harm them using their teeth.

Bullhead Catfish

Ameiurus sp. is the scientific name for Bullhead catfish. In terms of size, it is small to medium.

This North American fish species is the larger relative of the channel catfish. Finding it in tropical fish stores is next to impossible.

Despite their small to medium size, they can be aggressive to harm even larger koi. If you are not careful, their sharp spines can also harm you.


Procambarus sp. is the scientific name for crayfish.

Placing crayfish in a koi pond is strongly discouraged by experts. They can inflict severe damage particularly when the numbers get to their thousands inside a mud pond.

The Louisiana swamp crayfish is the biggest and most common offender. This invasive species has a very nasty temperament.

The electric blue crayfish that is normally available in local tropic fish stores may or may not act similarly in the same environment.

Marbled crayfish, also known as cloning crayfish or marmokrebs can be a good candidate for pairing with koi in a pond mainly because of their peaceful nature.

Note: Every crayfish devours and decimates plant life inside your aquarium or pond.

It is prudent to research your local laws regarding the kind of crayfish species you can possess and place inside your pond.

Common Plecostomus

Hypostomus sp. is the scientific name for Common Plecostomus.

They are typically a group of South American armored catfish commonly known as loricariids. Although it is alluring to add an algae eater to your pond, experts do not recommend putting Plecostomus and koi together for long.

In the warmer months, you can put plecos and koi together. However, during the cold months, you need to take them out.

You need to avoid putting koi in warm water permanently. In indoor ponds or aquariums where temperatures are stable, a middle ground where these two species can thrive is achievable.

Of great importance to note is that most plecos are omnivorous. They might end up inflicting wounds or sucking the slime coat off koi if they lack sustenance.

As it ages, plecos turn out to be less effective algae eaters. Once they start to mature, they begin craving for more meaty foods.

Bad Koi Pond Mates

The following are some of the fish species that you should not even consider putting inside a pond with koi:

Temperate Monster Fish

These are dangerous and aggressive fish. You need to avoid predatory ones like:

  • Snakehead
  • Bowfin
  • Pike
  • Bass

Some of the above are illegal in different states. For that reason, you need to report them when seen. In addition to that, you need to destroy them accordingly within the law when caught as you fish.

Most Tropical Fish

If you are a koi keeper, you understand that koi and tropical fish generally do not mix because of the differences in their temperature requirements. Nonetheless, if you reside in a climate where both species can flourish around the year, you have countless viable options available to you.

Because of the huge number of tropical fish that are available in the market today, you need to utilize your judgment and experience to establish what works with your case and what would result in disaster.

For instance, ripsaw catfish will likely perform better compared to redtail catfish. This is almost the same as comparing a sturgeon to one channel catfish.

Factors to Consider When Choosing Koi Pond Mates

You need to consider a few factors when choosing pond mates for your koi. Some of the most important things to keep in mind include:

  1. The most important factor you should consider is that the fish you intend to pair with your koi is not aggressive. The last thing you want is for another fish species to attach your koi. Ensure the fish you put into the pond is social and friendly.
  2. Another essential factor you should consider is that the fish needs to be of similar size to your koi.
  3. The temperature requirement needs to be similar. If this is not the case, make sure that the fish you choose can thrive or survive at a friendly temperature for koi.
  4. Your choice of fish should not need more care compared to koi. You do not want to meet the demand (s) of a foreigner fish at the expense of your koi.
  5. Your choice of fish species must not fight for food with koi.
  6. It is prudent to stock fish of the same size as your koi. If the other fish is a small size, make sure that your koi is of the same size and vice versa.
  7. You are better off choosing a bottom-feeding fish species for your koi.
  8. Choose a fish species whose temperament, character, and attributes are the same as koi. This will go miles in making sure that they co-exist in a friendly manner without any issues.

Final Words

Choosing koi pond mates is crucial. You need to consider plenty of things before choosing the fish species to stock in the same pond as your koi.

As we have already established, your choice of fish needs to share some attributes with your koi if their co-existence is to be successful. Two of the most important things that they should share are diet and temperament.

Their water temperature also needs to be the same.

We hope that you have learned everything you needed to learn about what fish can live with koi in a pond. If you boast vast experience in keeping koi and feel there are a fish species we have not included in this article, please let us know in the comments section below.

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