Goldfish will certainly eat each other if they are small enough and kept in the same tank. This, unfortunately, includes baby goldfish as well as some of the smaller goldfish that are seen as food for larger goldfish.
Fortunately, there are many ways of preventing this from happening as no hobbyists like to see their aquarium community diminishing in numbers!
Something else that goldfish like to eat is snail eggs, which can certainly be a good thing if you do not want them reproducing and overcrowding your tank.
Do Goldfish Eat Other Fish?
Yes, goldfish will eat other fish if they are small enough to fit in their mouths. However, they are not predators, meaning they will not go out of their way to attack and prey on smaller fish out of instinct.
When a goldfish eats another fish or their own kind it is typically done by accident or out of desperation when they are searching for food.
Do Goldfish Eat Snails?
Snails are brilliant to keep in a goldfish tank for a multitude of reasons, but they can still end up as a tasty snack for a goldfish if small enough. You may be OK with this if the snails are reproducing at a significant rate as it keeps the population controllable in your tank.
Do Goldfish Eat Shrimp?
Shrimp can be a good addition to a goldfish diet, however, if you are wanting to keep shrimp in your aquarium with the hopes that they will become a tank addition, you might want to keep them away from goldfish!
They are so small in size that goldfish will likely find them and eat them rather quickly. So, if you want your shrimp to survive, don't keep them with goldfish, or introduce much larger shrimp.
Do Goldfish Eat Their Babies?
Similar to most freshwater fish, goldfish will likely eat their babies upon hatching.
They produce hundreds of eggs when mating and also don't have parental instincts which means that they do not recognize their babies as their own.
This often leads to many goldfish fry going missing and unfortunately not making it to adulthood.
How To Prevent Goldfish from Eating Each Other
There is no totally proven way of stopping larger goldfish from eating smaller goldfish and other small fish. However, there are ways that you can help prevent it or reduce the likelihood of it happening. Here are some tips and advice.
Add More Plants and Decor
By adding more plants and other decor to your aquarium you will be providing your smaller fish with more hiding spots. Hiding places are essential in keeping your small fish safe from larger fish.
Feed Your Goldfish Properly
If you feed your goldfish their required amount they will be less likely to swim around your tank searching for food, which, in this case, are smaller goldfish and other fish.
Correct Water Parameters and Temperature
If the water quality is not good, it can cause your goldfish to become stressed out and sometimes aggressive with others.
Check your water temperature and parameters to ensure that they are stable for your goldfish and they should behave less aggressively.
Keep the Correct Amount of Goldfish in your Tank
An overcrowded tank will only lead to issues with your fish community. Make sure your tank has enough space to house large goldfish with small goldfish before anything else.
There are many opinions about how many gallons per goldfish, but what people miss is that there are a plethora of different types of goldfish that range in size and shape.
If you have a large goldfish, keep it in a minimum of 10 gallons, but if you want to have some smaller goldfish or other fish as well, you should extend the size by another 10 gallons or so.
If you are looking for inspiration on freshwater fish ideas for a 10 gallon tank, I think you'll enjoy this article we wrote.
Remember - the more space your fish have to breathe, the less agitated they will be which will help prevent them from eating others. The bigger the tank, the better!
Separate Goldfish from their Babies
To give your goldfish fry the best chance of surviving they will need to be separated upon hatching, or even before hatching by moving the eggs from the tank.
It is typically the mother that will begin eating them if they are left in the same tank after the pregnant goldfish has laid her eggs.
So, either acquire a small tank if you do not have one or a fish tank divider and ensure that the eggs or fry have been successfully separated until big enough.
Make sure the baby goldfish are being properly looked after and are growing quickly, whilst providing your adult goldfish with plenty of food to keep them full, then once big enough you can add the fry back to the main tank.
Most hobbyists at one point, or another, have kept goldfish - they are such awesome fish and do not require much experience or maintenance to live a healthy life!
However, if you believe that your goldfish are eating each other, other fish, or even their young, you must follow the steps in this guide to prevent any unwanted casualties.
Goldfish are no natural predators, so, for the most part, they will not go around actively looking to eat their own kind. However, it is entirely possible for it to happen and if it does, you will know exactly what to do.