Why Is My Clownfish Twitching? (It’s Nothing Serious)

This post may contain affiliate links. As an amazon associate I earn from qualifying purchase. Learn more

After years of hesitation, I decided to get into the saltwater aquarium hobby. I always wanted to have a reef tank, but I was afraid I wouldn’t have the appropriate knowledge to care for marine organisms. 

After all, all I heard is that this hobby is expensive, complex, and not suited for beginners. I have previous experience with freshwater tanks and extensive knowledge accumulated throughout the years, so I decided to pull the trigger and set up a saltwater tank. 

After the initial setup and the nitrogen cycle were completed, I bought two juvenile clownfish. Everything was going great until one day, I noticed one of the clownfish start twitching and shaking. 

It looked as it had seizures. I got scared and started researching this behavior. Spoiler alert; it’s nothing to worry about.

The twitching you are seeing is normal behavior among clownfish. It’s a communication of showing dominance or submission. Both females and males can do it, but males tend to do it more.

Keep reading if you want to learn more and find out why clownfish start twitching.


Clownfish Communication

Before I bought my first pair of clownfish, I read a lot of articles and spent many hours reading different threads about clownfish on many saltwater forums. 

I watched tons of videos and gathered as much information I could. I wanted to be prepared even though many hobbyists told me the clownfish are one of the easiest saltwater fish to take care of.

One particular thing that caught my attention was the weird behavior clownfish have. I never truly got it until I witnessed it with my own eyes.

Clownfish have an unusual way of communication. It’s nothing that I have seen before in any other fish. Clownfish do many weird things, and it’s not uncommon for owners to start worrying. But what’s odd for other fish, it’s normal for clownfish.

As many people refer to as a clownfish dance, clownfish twitching does not necessarily mean that the mating process has started. It’s usually a communication for establishing the status in the group.

Twitching As Social Behavior

I bought my clownfish as juveniles. You’ve probably done the same thing. 

Most people buy two clownfish at once, but it’s not uncommon for some to buy one clownfish and later on introduce another one.

Why is this important, you might ask? Because if one of the clownfish is bigger, it means that it’s already established as the female. A clownfish kept alone in an aquarium will turn into a female in a short period of time if it’s physically mature. The female will never be able to revert to a male again.

If you introduce new clownfish with the exact size, you will encounter problems. If the two clownfish are females, they will fight.

If you start with two juveniles with the exact size in a short period of time, you’ll begin to see an interesting behavior. One week after introducing them in the tank, my clownfish started to show twitching behavior.

Don’t mistake this with mating behavior. It’s dominance/submission behavior. The clownfish are trying to figure out which from them will be the dominant female and which will be the beta male. 

One of the clownfish will attack the other one. This is the dominant clownfish, and it will probably become the female later on. 

The submissive clownfish will turn sideways to the dominant clownfish and will start quivering like it has a seizure. This is a way of acknowledging the dominance of the other clownfish.  

In most cases, the dominant clownfish will accept the gesture and stop attacking the other clownfish. This type of behavior means that the clownfish are bonded and will become a pair when they sexually mature.

Twitching As Mating Behavior

When clownfish mature and pair up, a mating behavior begins. Two clownfish in a tank do not necessarily mean that they are a pair. 

Even if bonded, many conditions need to be aligned for the clownfish to start breeding. How do you know that the mating ritual has begun?

The smaller clownfish starts to quiver to show submissiveness to the female clownfish. The female will start twitching as acceptance of the submission. 

Some people call this dancing, but it’s the same thing. Twitching, dancing, or shaking are synonyms for this type of behavior. When you see this behavior in an established pair, then the female will lay eggs in a short period.

Interested to learn more about clownfish? Check out these articles:


As you have seen, clownfish twitching is nothing to worry about. In fact, it’s a good thing. It means that your clownfish are starting to bond, and a pair will form in no time.

The clownfish twitching is a sign of showing dominance or submission. It’s usually done by the smaller clownfish (the male), although females can do it as well. The male will quiver in front of the female as a gesture of acceptance that the female is the dominant clownfish.

Now that you know this information, you can start observing your clowns and enjoy this fantastic hobby again.

Leave a Comment