Do Koi Eat Other Fish?  

Do Koi Eat Other Fish?   
Do Koi Eat Other Fish?


In ornamental ponds and outdoor water gardens, koi fish are frequently used. Their vivid coloring was the reason they were initially bred in Japan. Originally only being seen in the colors black, blue, white, and red, these fish can now be found in other color-combinations. Although koi have been kept in Japan since the 1600s, the United Kingdom, Europe, and the United States did not begin to breed them until the 1900s.

If you’re considering building a koi pond, you might be curious about what koi eat and whether they get along with other fish. Koi are peaceful fish, but they also eat a variety of things.

How Large Can Koi Fish Grow?

The size of your fish should be one factor to consider when choosing them for your water garden. Knowing how big other fish are in relation to your koi is one way to decide if they are good cohabitants because, as previously said, koi will occasionally devour smaller fish. Knowing the size of your fish will help you decide whether a particular pond is large enough for them.

Koi’s size will change based on where it came from. Technically speaking, koi are a kind of the huge fish known as carp.

Will adult koi consume young koi?

Koi are known to devour their kids, thus the answer to the basic question of whether or not they do is yes. They may not always do it on purpose, though. Koi are omnivores, meaning they consume both plant and animal stuff, such as flies, algae, and bugs. The senior koi may not recognize its young when they are still eggs or koi fry, in which case they may eat them as though they were organic matter or some other little creature.

Koi are relatively huge fish, but they have relatively small mouths, thus they may have been in a desperate situation if they were eating their own babies.

They won’t be able to eat food that is too big if you give it to them.

Their own eggs would then be a good substitute in that situation.

What Additional Fish Do Koi Eat?

A mature koi will consume other fish in addition to baby fish. Be aware that if you keep any of the following fish in a tank, pond, or water garden, your mature koi may mistake them for food.

  1. Young Fish

A mature koi won’t have any issues eating other species’ fry if it won’t even eat its own babies.

Only mature fish should be added to your koi pond, if at all possible.

You may also like to read Why Don’t Goldfish Live Longer?

2. Minnows

Because they are resilient and low-maintenance, minnows are common freshwater tank fish. However, many minnow species are tiny fish. For instance, fathead minnows only get to be about 3 inches long. They make for very simple meal for your koi because they are so little.

3. Red and scarlet guppy

Guppies are a popular fish for novices, much like minnows. They can be beautiful additions to your home aquarium or water garden and come in a variety of colors, but if you also have koi, you should avoid getting guppies because they are at great risk of being eaten by your koi because they are 2.5 inches tall.

4. Elegant Goldfish

As long as they are roughly the same size, you can keep the majority of goldfish species with koi, but you should avoid keeping fancy goldfish with koi.

These fish are a little larger than the others on this list, at 8 inches, but they move very slowly, making them simple prey for koi. The larger types of koi may be especially drawn to fancy goldfish.


Koi are opportunistic eaters who will consume any available suitable plants or animals, despite the fact that you might not consider of them as predatory fish. This implies that they occasionally consume other fish, even their own young. It’s unlikely that this list of fish that koi will eat is complete. Always avoid adding young fish to your koi pond and keep in mind their size when choosing cohabitants for your koi.

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