Do Goldfish Eat Each Other? And How To Keep Them Together?

Do Goldfish Eat Each Other

One of the most common questions that keep coming up for goldfish owners is whether goldfish eat each other.

So do goldfish eat each other? Yes, goldfish do eat smaller goldfish if kept in the same tank. This is also the case with other popular types of fish, such as guppies and catfish.

As a fish keeper, odds are you’d like to prevent this from happening. Goldfish take time and money to raise, so it’s annoying and even upsetting when you go to check on your fish and notice a few missing. The good news is that there are steps you can take to prevent your larger goldfish from making lunch out of your smaller goldfish! And this small little guide will teach you how to do this. Here’s what you’ll learn:

  • Whether goldfish are predatory by nature;
  • How many goldfish you should keep in a tank;
  • Typical goldfish prey and food sources;
  • How to prevent goldfish cannibalism from occurring.

So keep reading…

Are Goldfish Predatory By Nature?

No, most goldfish are not predatory by nature. However, like all animals, food is a top priority for goldfish. So if they’re hungry, nothing is off-limits!

This increases the risk of baby goldfish being eaten if they are kept in a tank that has grown-up goldfish in it.

Any time “bite-sized” morsels are presented to a goldfish, they are typically not discriminatory about what they’re eating. And so goldfish won’t stop to consider whether their meal is a fellow tank-mate.

Moreover, goldfish will produce hundreds of eggs when they breed. But they don’t have the “parental gene” that some other animals have to make them mindful and protective of their spawn. They will graze on the eggs they lay without any consideration of the fact that the eggs are theirs. Not only that, when the eggs hatch, baby goldfish automatically become prey to their parents and any other larger aquatic animals.

But when it comes to the question of whether goldfish eat other fish that are fully-grown or even baby fish that have begun to grow, the answer is: generally not. Goldfish do not have aggressive tendencies, like the Betta (“Siamese fighting”) fish, and therefore will not attack other fish to kill and eat them.

However, when a fish dies in a community tank, goldfish may begin to eat the decomposing fish even before you’ve had a chance to remove it. So you should aim to remove dead fish as soon as possible to prevent pollution from occurring in your tank.

Recommended Further Reading:

How Many Goldfish Should You Keep In A Tank?

This is an important question about the original issue of goldfish eating other goldfish. There should be enough space in a tank for the number of goldfish you keep so that they can live comfortably.

You should ideally have 20 gallons of water for one goldfish, and 10 extra gallons for each one after that.

This is a bit more space and water than other popular fish species might need. But this much water is required because goldfish have a reputation for being notoriously “dirty,” producing a lot of waste and even growing to relatively large sizes.

Apart from that, tank size also plays a role when it comes to eating habits. If the fish tank is cramped, then it will be difficult for smaller fish to hide from their hunters.

So if you plan on breeding your fish, do ensure that you keep a large tank with lots of plants, rocks, and crevices. This will allow your smaller fish to survive. It will also improve the overall aesthetic quality of your tank, and keep the water clean and healthy.

Note: If the tank is bigger, waste will accumulate and pollute your water slowly. So you will need to clean the tank less frequently.

Recommended Further Reading: 6 Common Goldfish Tank Mates + (How And Why To Choose Them)

Goldfish And Its Prey!

Goldfish are active species of fish. So they are always on the lookout for food. If you casually look into a goldfish tank, you may notice goldfish attempting to eat the gravel or tank substrate too!

This kind of a big appetite is common in the larger species of goldfish, like Shubunkins, Lionheads, and Oranda breeds.

When it comes to food, goldfish need the nutrients found in live food, like worms, shrimp, etc. They will also eat live aquatic plants, like duckweed, because they are omnivores.

That said, most goldfish are more herbivorous than carnivorous. So make sure that they receive enough high-quality carbohydrate and protein sources to keep them healthy.

Further Reading:

Goldfish do not have a reputation for attacking and killing other adult fish because they are not a violent species. So goldfish are actually a great selection when setting up a community aquarium.

How To Prevent Goldfish Cannibalism?

So, what should you do if your goldfish gives birth to several babies, also known as “fry”?

First things first: separate the babies (or even the eggs) from the mother immediately to prevent her from eating them. Keep them in a breeding tank until they’ve had a chance to grow.

Leaving the eggs in the same tank dramatically increases the risk of cannibalism. So move the babies or the eggs to a “fry tank” with warm water for ideal hatching and growth conditions. 70-75 degrees Fahrenheit is generally ideal.

This is the simplest way to ensure that you get to keep and enjoy all of the baby fish!

After you separate the mother from her babies immediately, you should ensure that your fish are getting plenty to eat. This will reduce their appetite and may allow you to transfer the goldfish fry back into your main tank sooner.

Once the goldfish fry is 2-3 centimeters, it is generally safe to introduce your baby goldfish to the main tank.

You can acclimatize them slowly to the main tank water by placing them in plastic bags filled with their current tank’s water. Rest the bag on the water surface of your main tank where your grown goldfish and other fish are.

Related Interesting Reading: Can Goldfish Bite? [Actual Facts You Should Know]

Conclusion & Final Tips

It is fun and rewarding to keep Goldfish, which is why many fish owners have at least one goldfish!

If you suspect your goldfish is pregnant, or if she has hatched eggs, simply follow the guidelines listed in this guide for keeping the fry alive.

Goldfish are not predatory fish by nature but do eat live food if it is available. This means even a goldfish’s own babies are not off-limits when it comes to mealtime.

Always wait to acclimatize your goldfish fry to a community tank until they are big enough that most grown goldfish will no longer pose a threat.

Ensure that your fish receive plenty of highly-nutritious food sources. Additionally, also ensure that they have enough space, plants, and “hiding places” to reduce the likelihood of any potential attacks or threats from other tank inhabitants.

Cramped spaces can sometimes encourage aggression. This is a problem for smaller fish that are attempting to hide from larger fish if they feel threatened.

Goldfish make for lively and engaging pets and are easy and safe to keep in tanks with other grown fish. Compared with other fish that have a reputation for aggression, goldfish are friendly and docile and can be kept in communities without the risk of violence or cannibalism.

Enjoy your goldfish and your aquarium! Happy fish keeping!