Can Fish Have Seizures? {12 Ways To Help Right Away}

I remember panicking when I saw my fish twitching uncontrollably. Can fish have seizures?

Am I overexaggerating or is this a real thing? I want to help my fish and anyone in our aquarist community overcome this problem as well.

This is why I wrote a full and comprehensive article to help your fish as we find out, “Can fish have seizures?”

Can Fish Have Seizures?

Yes. Notice twitching, jerky movements in response to poor water quality, bright lights or an infection could resemble a seizure similar to humans.

Seizures involve muscle contractions that are uncontrolled.  A true seizure would involve an evolved brain in vertebrates with abnormal electrical discharges.

This is a hot topic in the aquarist community with a lack of conclusive studies, but you’ve come to the right place to dive deeper into fish seizures.

What Does a Fish Seizure Look Like?

If you think your fish is having a seizure, you might notice some the reactions below:

  • Twitching
  • Jerky movements
  • Shortness of breath
  • Gasping at the surface
  • Hiding in the corners or under decorations
  • Lying at the bottom

The nervous system of your fish could be disrupted by bacterial, fungal or parasitic infections. It could also be something as simple as bright flashing lights or the need to adjust temperatures in the tank.

Let’s keep going through this article to find out what we can do about fish seizures.

Can Flashing Lights Cause Fish Seizures?

Although studies are not defined enough to indicate that fish actually have seizures in the same regard as humans or other vertebrates, the jerky or twitching movements you are seeing look like a seizure.

The cause can be varied from temperature shock to infections, but bright lights alone may be the culprit. Some of us on our best days (or nights) forget to turn off the lights in or above our aquariums.

Our fish need rest too and excessive bright lights or flashing lights have been studied and induce twitching or abnormal muscular contractions in fish similar to seizures.

This is a reminder to all of us to keep lighting lower, keep away from flashing lights and turn lights off at nights to allow our fish to follow their diurnal cycle.

Why Is My Betta Fish Having a Seizure?

Your betta fish is one of the most common, popular and beautiful fish available in the aquarist community. Although they are hardy and able to withstand many water quality fluctuations, they are susceptible to infections that are:

  • Bacterial
  • Viral
  • Fungal
  • Parasitic

Have you seen your betta fish performing weird jerky movements that look uncontrollable? The infection can disrupt its nervous system and can lead to stress, illness or fatal injuries.

Nursing your betta fish back to health may require:

  • professional help
  • medication
  • lowered lighting
  • water changes
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5 Reasons Why Fish Have Seizures

Here are the 5 main reasons why your fish in seizing, twitching or jerking about uncontrollably with abnormal movements that they cannot control:

  1. Excessive or sudden noises
  2. Bright or flashing lights
  3. Infections
  4. Stress and Fear
  5. Temperature shock

1. Excessive or sudden noises

The lateral line system in fish captures sound through vibrations. These lateral lines are so sensitive that they can pick up on:

  • crashes
  • bangs
  • smashes
  • screaming
  • pumping bass
  • sirens
  • barking
  • thunder

In these moments, your fish can go into shock and start moving uncontrollably that looks like they are having a seizure or a convulsion.

2. Bright or flashing lights

Some fish are more sensitive to light than others.

  • Try to reduce lighting power or decide to turn the lights off for 12-14 hours a night instead of 8-10 hours.
  • Try using different colors such as red blue or green which are less intense.
  • Adjusting the lighting and limiting any flashing lights is essential.

An aquarium next to the TV with flashing lights from a movie or show could cause panic and twitching in fish. Add more hiding spaces and reduce the use of phones, TVs, flashlights around your aquarium.

3. Infections

Infections come in many forms and it’s one of our main jobs as aquarists and ecosystem managers to keep them out of our tanks and away from our fish. This is easier said than done in many cases.

Your fish could be suffering from infections that are:

  • bacterial
  • viral
  • fungal
  • parasitic

Convulsion may result from these infections and illnesses leading to death if untreated. The seizure could be a warning sign for us to react immediately and help.

4. Stress And Fear

Stress and fear in fish can lead to early death, Sometimes these fish suffer from convulsions or twitching before their demise. We can help by identifying signs of stress such as:

  • Overcrowding
  • Poor water quality
  • Illnesses
  • Bullying tank mates

5. Temperature Shock

Water changes or external temperature changes can affect the temperature of water in our tanks leading to shock. Water acclimation is a slow and patient task.

Matching the temperature of the bag water for new fish to introduce to your tank water needs to be slowly. Some use the drip system to make sure their fish adjust or else shock, twitching, or seizure-like movements may result.

Can Molly Fish Have Seizures?

Yes. What you notice in your molly fish could be instant movements that seem uncontrollable. The nervous system of this molly fish is disrupted by external factors.

Molly fish are susceptible to seizure symptoms that include convulsions leading to an early death if not treated. Other fish that can experience the same seizure-like symptoms include:

  • Angelfish
  • Betta Fish
  • Catfish
  • Goldfish
  • Guppies
  • Neon Tetras
  • Platy Fish
  • Oscar fish

What Are The Shimmies?

The shimmies is a term used to describe an illness that is common in livebearer fish. The shimmy is a movement where their bodies rock from side to side.

It may look smoother and less twitchy than experiencing or witnessing a fish going through conclusion or jerky movements. The shimmies may occur when:

  • Temperatures are too low
  • pH too acidic
  • Low minerals and nutrition

Your fish might be shimmying, quivering or twitching from poor conditions or sudden changes to their health. Although it may look cute, this is a matter to be taken seriously.

How To Help A Fish Down With a Seizure

A frantic, twitchy, jerky fish may be experiencing what looks like a seizure. You can help in the following ways:

  1. Remove decoration and open up more space to prevent injuries from this uncontrollable movements
  2. Use vinegar to neutralize pH. Spray a little a time to notice a difference.
  3. Neutralize ammonia spikes with hydrogen peroxide.
  4. Get medical help from a vet.
  5. Prevent Overcrowding.
  6. Maintain the best water quality possible.
  7. Avoid temperature shocks from warm to cold.
  8. Do not let anyone tap on the glass of the tank.
  9. Reduce lighting.
  10. Acclimate new fish slowly.
  11. Improve nutrition.
  12. Use an air pump for increased oxygenation.


What to look for when your fish is having a seizure can range from the following factors below:

  • loss in appetite
  • pale or bluish skin
  • slow movements and breathing
  • erratic swimming
  • uncoordinated fin movements
  • head droops down
  • upside down swimming
  • swimming in circles
  • twitching
  • convulsions

We hope you can refer to this article for signs, causes and solutions to help your fish who could be experiencing a seizure. All the best to you and your effort in caring for your tank’s ecosystem and we encourage you to continue your journey with us at!

John Brandon

John has kept fish all his life (since he was about 5). He started with keeping guppies and fell in love with fish keeping almost straight away. That was 40 odd years ago. These days John still keeps fish and currently has two large tanks where he keeps many different types of fish such as Angelfish, Neon Tetras, Goldfish, Guppies and many more.