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You are watching: Do koi fish eat other fish

Although koi are gentle fish, they’re quiet opportunistic feeders, and also won’t hesitate come swallow much smaller fish.

Koi space the tamed descendants the the usual carp, i beg your pardon are normally rather calm and also easily tamed. As a an outcome of this and also centuries that domestication, koi space customarily gentle giants that get along well through each other and also many other creatures together well, so long as your dietary needs and water quality needs are met.

However, they room opportunistic omnivores, and are well-known to eat smaller sized fish types as well as fry if they have the opportunity. In fact, they’ll also eat their own fry! Females lay hundreds of eggs, and also leading increase to the moment that this hatch they will often nibble top top them. In some cases, together as once pond is overstocked or over there is too small food, koi siblings may eat each various other for sustenance as well as to mitigate competition. However, this instances aren’t common and also so long as you keep your koi healthy and also with ideal pond mates, all of your pond’s residents should live strong, happy lives!

Make sure to feed your koi a well balanced diet and also keep your pond within the essential parameters – water temperature need to be in between 59 and also 77 degrees Fahrenheit (15 come 25° C), through a pH variety of 7.5 come 8 and dissolved oxygen in ~ or over 7 components per million. Below, we’ll cover the key fish varieties that do not do it be retained with koi, as well as ways to aid prevent the predation of smaller fish.

What Pond Fish will Koi Carp Eat? 

1) Guppies (Poecilia reticulata)


Will Koi Eat Guppies? Answer: Yes, high risk.

At just 2.5 inches lengthy at your maximum adult size, guppies room quite little fish that room resultantly easy prey because that koi. Despite their size, lock hardy tiny fish may be to resist temperature fluctuations exterior of their 55 come 86° F (13 come 30° C) range, despite pH should be kept relatively alkaline between 7 and also 8. In addition, guppies will eat algae and mosquito larvae, do them appropriate pond fish, specifically for start ponders, but not v koi.

2) Minnows (Phoxinus phoxinus)

Common Minnows. Picture by Etrusko25, obtainable under a an imaginative Commons ShareAlike 3.0 license.

Will Koi Eat Minnows? Answer: Yes, high risk.

While over there are numerous different subspecies the minnows, fathead minnows space the most widely kept selection and so it is the subspecies that we’ll focus on here. Fatheads, additionally known as the usual minnow, flourish to a maximum size of 3 customs or less and are typically a dusky-grey shade with a lighter, frequently silvery underbelly and also a brown-black stripe running horizontally follow me their side.

They do well in cooler waters varying from 53 to 68° F (12 come 20° C) v a pH between around 7-7.5, though they’re one of the toughest pond fish species and can withstand fluctuations in both of these and also illness, low dissolved oxygen, and also turbidity so long as none of these conditions lasts for an extensive period.

3) Danios (Cyprinidae)


Will Koi Eat Danios? Answer: Yes, high risk.

With several varieties available, danios can range in dimension from just an inch in most varieties to the largest, large danios, farming up to 5 inch in length – still little enough come tempt part koi. Despite also reasonably hardy, pH must be kept in between 7.0 and also 7.8 and temperature in between 70° and also 78° F (21-25.5° C). Their all at once appearance counts on the variety – because that example, zebra danios space brown and also white v horizontal grey-black horizontal striping all follow me their bodies, while celestial pearl danios are quite colorful with bright red-orange fins and underbelly through a black color body and little yellow spots.

4) an elaborate Goldfish (Cyprinidae)


Will Koi Eat an elaborate Goldfish? Answer: Yes, low risk (small species).

While standard common goldfish space usually alright to store with koi, sophisticated goldfish, specifically the smaller varieties, have to not be maintained with koi. This is due to the fact that they tend to be much slower than usual goldfish, and also as together are straightforward targets because that koi. Also if the koi nothing eat them, the unhurried nature the fancies way that they’ll have actually a tough time getting sufficient food prior to koi and also any various other speedier fish eat the all.

The popular Aggression that Koi Experiment explores what happens when koi and several popular an elaborate goldfish varieties are retained together. If you pick to have an elaborate goldfish (separate indigenous koi, the course), their temperature choice is 65 to 75° F (about 18-24° F) and pH must be maintained somewhere in between 6 and 8, keeping in psychic that various varieties will have slightly various needs.

5) Mollies (Poecilia sphenops)


Will Koi Eat Mollies? Answer: Yes, tool risk.

As with most of the fish in this article, mollies come in a wide assortment of varieties (39 species, in fact!), v each having different needs and also appearances. As such, if you great to have actually mollies you should conduct study on the specific type that you would certainly like. Overall, however, mollies prefer warmth waters between approximately 75 and 85° F (24-29° C) and a pH above 7. They have the right to be completely sooty black, speckled with miscellaneous colors, have actually Dalmatian-like patterning, or any variety of other colorations and also patterns depending upon the particular species.

Size can range from just 2 inches come 6 or an ext inches – the larger species, sailfin mollies, tend to be more expensive but are much less likely to be consumed by koi if you combine them right into your pond together full-grown adults.

6) Barbs (Cyprinidae)


Will Koi Eat Barbs? Answer: Yes, tool risk (small species).

Also with many varieties available, barbs variety in dimension from just an inch to end a foot through a striking array of color options. The larger varieties, such as the bright silver 8+ customs tinfoil barb, are likely to do just fine v koi, specifically given the trusted nature of barbs, however smaller ones favor the 2 customs pentazona barb must be maintained separate.

The europe barb ranges do ideal with temperatures frequently somewhere in between 70 and also 75° F (21-24° C), when African arrays of course need warmer waters. Part barbs, such together the yellow barb, favor water temperature that space in the mid to top 60’s Fahrenheit, for this reason as always be certain to conduct additional research into the exact selection that works ideal for your location and pond.

7) little Catfish (Siluriformes)


Will Koi Eat Catfish? Answer: Yes, low danger (small species).

Small catfish types that can be preserved in ponds and aquariums incorporate the cory catfish, glass catfish, bumblebee catfish, bristlenose plecos, and also many others. As result of their little size (typically less than 4 inches), they need to not be kept with koi if you desire to it is in 100% sure they won’t be eaten or damaged. As numerous are bottom feeders and also less most likely to it is in constantly about the mouths that koi, especially throughout surface feeding times, they’re safer than other small fish here.

The appearance as well as water quality needs depend entirely on the species, though most of them are omnivores and will consume a mix that insects, vegetables, part fruits, algae, and also other smaller fish.

8) Juveniles & Fry


Will Koi Eat Fry? Answer: Yes, high risk.

Juvenile fish are, the course, ~ above the smaller sized side and also as together are an ext likely to be eaten by koi. Try to just keep fish that room close come the exact same size as your koi or larger, as obviously your koi will certainly not be able to eat this fish. As pointed out above, koi will certainly happily eat fish fry, even if it’s your own! as such, it’s best to incorporate only adult fish that other varieties into your koi pond, as the koi are most likely to eat any kind of fry or juveniles. You can keep juveniles and fry in a different pond or a tank until they are large enough to it is in in the pond v the koi.

How to protect against Koi from Eating smaller Fish (Tips & Tricks)

Artificial shelters are a great way come keep smaller sized fish safe by offering them extra hiding spots.

Though it can be challenging to keep smaller sized fish through koi, that not difficult by any means. Some pond keeprs have been maybe to store koi and smaller fish together without incident, yet if her koi are reflecting interest in other fish, there room some preventative actions that you deserve to take.

First and foremost, make certain that her pond is large enough to comfortably accommodate all of your fish even once all of them reach your adult size. Save your pond clean and maintained, while likewise feeding her koi adequate quantities of high top quality feed so that they aren’t hungry and also are as such less likely to food on other fish. You should also incorporate a range of hiding areas into her pond for smaller sized fish. This can incorporate a big amount of plants (which room extremely helpful to water quality, anyway), rocks, tunnels, fish shelters, and shallower locations along the sheet that room too shallow because that koi to get into but that smaller sized fish deserve to escape come if needed. Make sure there space plenty that both floating and also emergent tree in these shallow areas, together as native lilies, to help keep the water cool together it will warm up much faster than the rest of the pond.

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As discussed above, girlfriend can additionally keep young fish and also fry quarantined away from koi until they are large enough to safely it is in together. A perhaps less conventional an approach is to produce a partition in your pond the isn’t visible from over but the will keep koi and smaller fish in separate locations of the pond, again making certain that there is enough room for every one of them.