Do koi eat other fish? And do they eat goldfish? Are koi aggressive to other fish?
Many first-time koi keepers wonder about the possibility of keeping other coldwater fish such as goldfish alongside their koi.
One of the most important elements of keeping a healthy, happy pond is ensuring that all of the pond’s residents get on well with each other… and will not eat each other!
So, if you’re wondering whether koi eat other fish and if it’s safe to keep goldfish and koi carp together, this article will answer all of your questions…
What do koi fish eat?
The koi carp is an omnivorous fish, which means that koi will eat both plants and animal matter. In the wild, this will consist of many foods, including algae, plants, flies and bugs, and decaying organic matter.
Will koi fish eat goldfish?
The koi carp and the goldfish are actually fish from the same species family. While there are significant differences between them, they also have a lot of similarities. But this won’t stop larger fish from trying to eat smaller ones!
Koi carp are unlikely to eat other large fish, including large goldfish. However, if something will fit in their mouths, then they may well try to eat it! So smaller goldfish will be at risk.
Koi will also eat fish eggs. So if your goldfish or koi lay eggs within the pond, your koi may potentially see these as a fair meal!
What if your goldfish are disappearing from your pond?
If you notice that your goldfish are not surviving alongside your koi or seem to be disappearing from the pond – and if your goldfish is small enough to fit in the koi’s mouth – then it may be that your koi are eating them. However, there are other possible explanations for your goldfish disappearing…
Firstly, koi ponds are almost always large and deep. If your fish are swimming near the bottom, it is certainly possible to not see them.
Secondly, predators such as herons, other wading birds and even dogs and cats could be responsible for eating your goldfish.