Can Goldfish Bite? Learn The Truth

All fish have teeth and goldfish are no different. These teeth are designed for their eating habits. Some have teeth that are designed to catch and kill prey. Others have teeth that are designed just for holding onto their food. In the case of a goldfish, they have teeth and it’s basically used for holding food and moving it to their stomach. Since goldfish have teeth, you may be wondering if they can bite.

So can goldfish bite? Goldfish can bite and there are many reasons why they do. They will bite to defend themselves, protect their territories, to catch food, and when they are sick. While they do bite, to a human, they are usually harmless and won’t hurt.

In this short guide, we’ll go through why goldfish bite, what to do if they bite, and how to prevent them from biting.

Do Goldfish Have Teeth?

All species of goldfish do have teeth which are called pharyngeal teeth. Unlike most animals that have teeth up front, goldfish have teeth that’s far back in their throats. These teeth are located in the pharynx area of their mouth.

The teeth of a goldfish are small and flat with a simple purpose. It’s designed to help hold onto their food they catch and grind them up for easier digestion.

Goldfish will lose their teeth throughout their lives. There are many reasons why their tooth falls out. One of the reasons is as they get older, they also get bigger. Therefore, their tooth will fall out to make room for a bigger tooth.

Another reason is the food they eat. Goldfish are opportunist fish so they’ll eat anything that they can fit in their mouth. Food like plants and insects will require their teeth to be used often and will place a lot of stress on it as well. As a result, the teeth will fall out to replace them with newer ones.

The tooth that falls out will fall to the bottom of the tank. The bigger the goldfish is, the bigger their teeth are and easier to spot when it’s fallen to the bottom of the aquarium.



do goldfish have teeth

Can Goldfish Bites You?

Yes, they can bite you, but it’s usually nipping. Goldfish are playful fish and they will go after anything that seems like food. So if you have your fingers in the water, they will nip at it thinking it’s food. Once they realize it’s not food, they will swim away.

Their only instinct is to go after anything that looks like food. In the wild, food will sometime become scarce. Therefore, they will try to eat anything and everything that they can get a hold of, including your fingers.

Does Goldfish Bite Hurt?

Since their teeth are very small, more than likely, it will not hurt when goldfish bite. It will feel more like a pinch.

Goldfish do not bite as other animals would. Their biting is to grind the food into smaller pieces so it’ll be easier to digest. Goldfish don’t have a stomach so any food that get eaten will go through their intestine fairly quickly.

overcrowded goldfish aquarium

Common Reasons Why Goldfish Bite

Feeding Time

During feeding, goldfish may start to become aggressive at other fish. In the wild, food sometimes becomes scarce and for that reason, their instinct will be to eat as much food as possible. As they feed, they may occasionally bite other fish to chase them away.

If you have a lot of goldfish in the aquarium, especially if they are smaller than other fish, pay attention to them. Some of the larger goldfish or fish might get aggressive and start biting the smaller goldfish.


During the mating season, male goldfish will start to chase the female goldfish around in the tank. This is his way of displaying an attraction to her.

As he gets close enough to her, he will nip at the fins or the body. Sometimes, the nipping will cause a cut in her fins. However, this won’t hurt the female goldfish at all.

If she doesn’t resist the male goldfish advance, they will begin to mate.

Overcrowded Aquarium

While a lot of fish in an aquarium may seem harmless, it’s actually not. When an aquarium is overcrowded, the goldfish will have no room to swim. This will cause them to become stressed.

Goldfish that are stressed will likely start to become very aggressive and agitated. This will lead them to bite other fish and anything else that’s around them.

To remedy this problem, you’ll need to remove some fish from the aquarium or get a bigger tank to accommodate all of them. The recommended tank size will depend on the species of the fish that’s in the aquarium. For common goldfish, it should be 1 goldfish for every 5 gallons of water.

Water Quality

When there are too many fish in the aquarium, the quality of the water will decrease. This is mostly due to the waste from the fish and uneaten food that falls to the bottom.

Having a filter will help clean up the water, but not enough to keep the water quality at a good level.

As the quality of the water worsens, the goldfish will have a harder time breathing due to a lack of oxygen.

If there are a lot of fish in the aquarium, there are a couple of ways to remedy the problem.

One of them is changing the water more frequently. Once a week is usually enough to keep the water quality at a good level. Always remove 30 percent of the total tank’s water capacity.

So, if you have a 10-gallon aquarium, remove 3 gallons of the water from the tank. Then replace the old water with 3 gallons of fresh clean water. With the water change, it’s recommended to treat the water with a water conditioner.

By doing water changes more frequently, the filter will not work as hard and the goldfish will have more oxygen to breathe.

Another way to keep the water quality at a good level is to remove some of the fish from the tank. For goldfish, it’s best to keep 1 goldfish for every 5 gallons of water.

common goldfish

What To Do When Goldfish Is Biting Other Fish

Goldfish are usually shy creatures, but when they are starting to bite, it means they are not happy. The other fish may be bullying them or a new fish was just introduced to the aquarium.

Before doing anything, watch them carefully to see how serious it is. If the goldfish is just nipping at each other, it means they are just playing around.

On the other hand, if the biting seems to be serious, you’ll need to act quickly or an injury may happen to the goldfish. Worse, biting could cause death.

When you suspect the biting is endangering their life or other fish, you have two options. One of them is to remove the fish that’s causing the goldfish to act aggressive and bite. This could be just one fish or multiples of fish. It’s best to remove all of them into another tank.

If another tank is not possible, you could simply put a fence into the aquarium. This should keep them away from each other and avoid biting.

Another option would be to remove the goldfish that’s biting and put them into their own tank. After a couple of weeks, you can try to introduce the goldfish into the main tank and see if the aggression is gone.

Related Questions

Do Goldfish Chew Their Food?

Depending on how large their food is, they will chew it to make it smaller so it’ll be easier to digest. Food like fish flakes will just get sucked into their stomach.

Do Goldfish Have Sharp Teeth?

The teeth of a goldfish are sharp, but not enough to penetrate your skin. However, it’s sharp enough to cut through plants and insects.

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