Betta Fish Behavior Before Death – 8 Signs To Look Out For

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It can be upsetting to you as a Betta fish owner watching your fish and thinking it could be dying.

You can recognize Betta Fish behavior before death.

The good news is that there are some warning signs that can easily be identified before they reach that point.

By monitoring its behavior and general appearance, you can detect if your Betta fish is dying.

Lethargy, color loss, decreased appetite, frequent breathing, and other symptoms are common in dying Bettas.

Here are eight telltale signs that your betta fish could be dying.


One of the most common signs of Betta fish behavior before death is lethargy.

Bettas are normally very lively and active fish that take great pleasure in investigating their surroundings during the daylight hours.

However, when they are unwell, they have less energy than usual, and they become much more lethargic than they normally are.

You will notice that your Betta spends a greater amount of time on the bottom of the tank, hovering among the plants and hardly moves at all.

A Betta, who is getting older, is also dealing with the same issue.

When there is a problem with the temperature of the tank, the level of ammonia or nitrate in the water, or illness, they have a tendency to become more lethargic than they were previously.


Your Betta fish could pass away suddenly purely from stress especially if it has been stressed for a long period of time.

Unfortunately, there are no clear signs that your fish is stressed.

Because of this, it is your obligation to ensure that they are living the best life possible and are not under any unnecessary strain.

Stressful situations for Betta fish include the following:

Tapping on the glass 

You might think that tapping on the fish store’s glass isn’t a big deal because you see children doing it all the time.

Tapping on the aquarium glass sends a sound wave through the water, affecting the Betta’s ability to react to and feel vibrations.

They can also hear the knocking sound which is distressing for them.

So, if you see someone doing this please stop them and educate them on why they should not do this.

You might actually notice signs up in pet stores asking people not to tap on the glass.

Tank Mates

Unsuitable tank mates who chase or hurt your Betta are a major source of stress and can lead to death or serious illness.

Betta’s do not cope well with aggressive or large fish.

You can never put two male Betta’s in the same tank as they will fight each other and will continue to do so until one of them is dead.

It is also not advisable to put a female Betta in the same tank as a male Betta unless it is a planned mating with full supervision.

The fish need to be separated as soon as they have finished breeding.

Dimensions of the tank

The tank’s size is critical because if it is too small your Betta may suffer, making it susceptible to illness and death. Contrary to popular belief, a Betta should never be housed in a tank smaller than 5 gallons.

Actually a 20 gallon tank is the perfect size for a community Betta fish tank.

If your Betta is too aggressive for a community tank then buy a 10 gallon so that he has some space to swim around in.

Stay away from vases, even if it is fashionable and use a bowl with caution.

Water quality

The tank’s water quality must be maintained at a high level, and water changes must be performed on a regular basis.

If the water becomes dirty or the ammonia levels rise too high, betta fish can become quite stressed and even even pass away.

Ammonia is very toxic to fish.

How to tell if Betta fish is dying.

Fading Colors

A sudden loss of color  is another worrying symptom that should be acted upon very quickly.

If there is a noticeable difference in color, it can be because your Betta fish is suffering from a serious illness.

Betta fish are susceptible to a wide range of health problems, some of which include bacterial infections, fungal infections, and parasite disorders.

The coloration of a Betta fish will begin to fade if it is afflicted by any of these conditions.

If the scales are changing into a different color, it could merely be the marble gene.

But if the dulling is minimal, it could be an indication that your Betta is getting older.

The Betta can undergo a color shift at any point in their lives if they carry the marble gene.

In addition, the gene can either lighten or darken the fish, depending on environmental factors.

Older Bettas have a tendency to become a shade or two lighter as they age.

Fish TB

Fish TB is caused by a bacteria called Mycobacterium marinum.

Although this bacteria can be found in almost all aquariums, they rarely affect Betta fish.

Fish TB is particularly dangerous since you won’t detect any symptoms if your fish are infected.

Even before you notice any symptoms, your fish could have been infected with tuberculosis 6 months prior.

Fish infected with tuberculosis become lethargic and lose their pigmentation. 

Fish TB is a terrible zoonotic disease, meaning it can spread from animals to people.

You can get it from your fish if they tuberculosis.

When working with TB-infected fish, it is crucial to use gloves and avoid all physical contact with the affected fish.

Make sure to sanitize your hands afterwards.

No Appetite

A loss of appetite can be due to old age or sickness.

The way to tell which one it is by how long it takes for your Betta to stop eating.

If your fish gradually stops eating then it could be due to old age.

This normally takes place over a few weeks or even months.

If the lack of appetite is sudden then the cause is most probably some sort of illness.

Because a Betta’s metabolism slows down as it gets older, it won’t need nearly as much food as it did when it was younger.

Rapid Breathing

Another indicator Betta fish behavior before death is very fast breathing.

A sick or elderly fish will exhale more quickly than usual.

The change in elderly fish is subtle, and you may not notice it until you compare it to a younger one.

However, you will be able to detect the symptoms of a sick fish within one or two days, or perhaps in only a few hours in extreme circumstances.

Rapid breathing with any fish can be due to low oxygen levels in the fish tank as they are trying to get more oxygen into their bodies so they breathe faster to try and accomplish this.

Heavy breathing, on the other hand, might be caused by stressful situations like chemical pollution, underlying health issues, or excessive ammonia levels.

The first step is to use a water test kit and test the fish tank’s water.

If anything is off then do an immediate 50% water change.

If your Betta is taking in more atmospheric air than usual and staying close to the surface of the water then there’s a problem with the water quality in your tank.

Betta lying at bottom

Lying At The Bottom Of The Tank

Fish should swim at the water’s surface, in the middle, or at the bottom.

They should not linger on the tank’s surface or at its bottom (except for bottom feeders like Cory Catfish).

Although there are a variety of reasons why a Betta may lie down at the bottom, some are alarming while others are not.

Bettas typically take a nap near the bottom of the aquarium.

However, you should be concerned if you find them resting more frequently than usual.

When a Betta reaches the end of its life, it will also lie down at the bottom of the tank.

It’s a serious indicator if your Betta fish is lying flat at the bottom of the tank.

Your fish will most likely not live much longer if it is displaying this behavior.

Raised Scales

If your Betta’s scales are raised, your fish is most likely suffering from dropsy.

Dropsy is not a symptom of aging, but it could be a sign of kidney failure, infection, or a poor diet.

Healing any severe organ failure in a fish is, of course, difficult, if not impossible.

Dropsy is a disease that almost invariably results in death.

Extreme swelling, typically accompanied by pine-coning scales, is a sure indicator of dropsy in a Betta fish.

When the kidneys fail, fluid builds up in the body of the fish, causing it to enlarge.

Fungus, injury, aging, parasites, and bacteria are the most common causes of kidney failure in fish.

A bacterial infection is the only sort of kidney failure that can be treated in fish, and it’s usually treated with unscented Epson salts or Kanaplex.


Make sure to familiarize yourself with how your Betta fish behaves and learn his habits.

You will then know when your Betta is not feeling well or if he is nearing the end of his life.

It is very important to act quickly if you think that your Betta fish is sick.

If you take too long then you might not get the outcome that you desire.

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Irma Bense is the founder of She has over 42 years of experience in keeping fish.She has kept both freshwater and saltwater fish through the years.She has extensive knowledge in breeding numerous species of fish from Show Guppies, Cory Catfish, German Blue Rams to Apistogrammas.You can learn more about Irma on the 'About' page.

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