While we typically expect pet fish to float when they die, this isn’t always the case.
Betta fish will often sink when they die, although this depends on the cause of death. Furthermore, a floating betta fish may not be dead just yet, so it’s worth examining it closely to find out!
Here, I’ll run you through all the reasons that your betta fish could be floating and offer you my best advice on what to do if you find a floating betta fish.
Why Is My Betta Fish Floating?
Just because your betta fish is floating, it doesn’t necessarily mean it’s dead. It could also be an indication of:
Swim Bladder Disorder
Swim bladder disorder (aka. swim bladder disease) is, sadly, a fairly common problem in betta fish.
The swim bladder is an organ filled with air that regulates your betta’s buoyancy and orientation in the water.
If something goes wrong with the swim bladder, your pet fish may struggle to maintain its position in the water and may swim on its side, upside down, near the bottom of the tank, or near the surface.
In extreme cases, your betta may even end up floating at the water’s surface, unable to swim downwards.
Causes of Swim Bladder Disorder
Swim bladder disorder is normally caused directly (or possibly indirectly) by overfeeding. A betta that overeats is prone to bloating, constipation and, in severe cases, swim bladder problems.
But swim bladder problems can occasionally be caused by other health issues, too, such as bacterial and parasitic infections that are especially common in tanks with poor water quality – sometimes also caused by overfeeding!
Treating Swim Bladder Disorder
In the case of overeating, mild swim bladder disorder can normally be remedied by fasting your betta, and feeding them cooked peas as a laxative.
If your betta is floating, however, it signifies an especially severe form of swim bladder disorder. One of the few home remedies in such a situation is to treat your betta with a powerful laxative such as Epsom salts.
If there is an underlying disease, you need to address that too.
In mild cases, swim bladder disorder can usually be remedied fairly swiftly, but if your betta is floating, the chances of a full recovery are slimmer. In such a serious case, you may wish to take your precious fish to a specialist vet.
Shock in Betta Fish
If your betta fish has received a severe shock, its system might be so overwhelmed that it ends up hanging around at the water’s surface or even floating on its side.
Causes of shock can include a sudden change in temperature or water chemistry, severe ammonia poisoning, or bullying from other tank mates.
If you suspect that your betta is suffering from shock, try to correct the root cause of the problem as soon as possible – it could save his life.
Near Death Betta Fish
If your betta fish is suffering from a disease or otherwise feeling very sick, he may hang around at the top of the aquarium, fairly motionless, perhaps breathing rapidly.
If conditions don’t improve, he may lose more and more of his motor ability, and begin floating at the water’s surface.
As always, try to diagnose and treat any disease that your betta might have as soon as possible. Check out our disease care archives to help you determine the cause of the problem and the solution.
How Do I Know If My Pet Betta Fish Is Dead?
Since there are other reasons that your betta fish may be floating, how can you know for sure if he is dead?
Breathing Has Stopped
You can normally tell if your betta is dead or alive without touching him by looking to see if he’s stopped breathing.
Just like every other fish, bettas need oxygen to live and just as a living person will breathe in and out, a living betta will continuously pulse its gills open and closed as it filters oxygen into its bloodstream.
If you don’t see even the slight movement of gills, your betta is almost certainly dead. Be mindful, however, that a betta fish that’s almost dead may go a long time without breathing, or make such tiny gill movements that they’re almost indistinct.
To make sure, you need to examine your fish.
Examine Your Betta
Use your aquarium net to scoop up your betta. With a rubber glove on, gently touch your fish. If he’s dead his body will feel stiff and won’t move by itself.
If your betta does move, however, he is still alive but critically ill. Your only small chance of saving him at this stage is to attempt an emergency 45% water change with treated water and see if the fresh, well-oxygenated, clean water is enough to revive him.
If your betta does miraculously recover, you need to work quickly on finding the root cause of the problem. Check your fish for symptoms of disease, and test your water to see if ammonia or nitrite poisoning was to blame.
Can a Dead Betta Fish Sink?
Although bettas suffering from bloat or swim bladder disorder may float when they die, in other cases your betta’s dead body may sink to the bottom of the fish tank.
In this case, you can do the same preliminary optical checks for breathing before attempting to scoop out your fish for confirmation. A dead betta fish will also have cloudy eyes and dull colors.
If you discover that your fish is alive, you need to work quickly to identify the problem and try to save his life.
Why Is My Betta Stuck at the Bottom of the Tank?
If your betta is stuck at the bottom of the tank but still alive, it could be suffering from several possible health problems. Check his body carefully for signs of disease, and refer to our disease archive to identify and treat the problem.
The most likely ailment, once again, is swim bladder disorder. As well as causing the fish to float in some instances, swim bladder disease can make a fish sink uncontrollably to the bottom of the tank. Follow the advice given above on how to treat a serious instance of the disease.
Dead Betta Fish Stuck to Filter Intake
In some cases, you may find your dead betta fish stuck to the intake of your aquarium filter. This can be very distressing and may make you wonder if the filter had sucked in your fish and caused its death.
Luckily, this is quite rare but depends a lot on the strength of your filter current, as well as the swimming ability of your betta fish.
Bettas with long fins are particularly prone to getting sucked into filters because they have a weaker swimming capacity. If their fins can get dragged into the filter intake, the rest of their body can sometimes follow.
The vast majority of the time, however, a betta fish found on the filter’s intake will have died first and then got sucked into the intake afterward.
Even so, strong filters should always be avoided in betta tanks. Even if the intake doesn’t pose an immediate risk, betta fish hate strong currents and will become stressed and even exhausted if constantly made to struggle against a strong filter flow.
Did My Shrimp Eat My Betta Fish?!
Another shocking place to discover a dead betta fish is in the clutches of your pet shrimp!
Such instances have made many aquarists wonder whether their shrimp had in fact killed their betta to eat it! Normally, you’d need to be more worried about your betta attacking your shrimp, so how could this be possible?
Once again, in the overwhelming majority of cases, your betta will have simply ended up in the claws of your shrimp once it was already dead. Shrimp are classic scavengers and won’t turn down a free meal that comes their way!
But while most aquarium shrimp are relatively peaceful and unlikely to harm a live fish, some more predatory species of shrimp may occasionally be tempted to go after a healthy betta fish, too.
Whisker shrimp are particularly notorious for hunting fish, and some aquarists have reported attacks on their bettas. Sadly, Whisker shrimp are sometimes mistakenly sold as ghost shrimp, so it’s a good idea to know the difference between them!
How Do I Know My Betta is Going to Die?
If your betta fish has been looking poorly for a while, he’s likely succumbing to poor water quality, an illness or disease, or perhaps simply old age.
Symptoms of a betta that might soon die include:
- Lack of appetite – a telltale sign of illness is when your betta refuses food.
- Become dull in color – a sick fish will often lose its bright coloration, becoming paler and duller than they usually are.
- Lethargy – a dying fish may appear to be very exhausted and unresponsive to stimulus.
- Clamped fins – a betta fish will often pin its fins tight against its body when unwell or dying.
Causes of Sudden Death in Betta Fish
It can be incredibly upsetting to come home and find the body of your dead betta fish, floating at the top of the tank.
If your betta fish seemed healthy and wasn’t exhibiting any of the above symptoms, you may be wondering what could have caused him to die so quickly.
Ammonia or Nitrite Poisoning
If your tank is not cycled properly or you’ve had a problem with your biological filter, nitrite, and ammonia poisoning can kill your betta fish very quickly.
Even if your betta looked fine a few days ago, a sudden ammonia spike can quickly destroy even a fairly healthy fish.
Test your tank’s water parameters with a test kit to see if ammonia or nitrite was to blame.
If the water temperature of your tank changed very quickly, or if your betta experienced a sudden temperature shift when introduced to the tank, it may have suffered from thermal shock which can cause sudden death.
Check your tank’s thermometer and see if your heater is working properly.
Bullying from Tank Mates
Betta fish may be aggressive fish but they are also fairly delicate and can be vulnerable to attack from other fish.
Fish that nip fins such as Serpae tetra and barbs are especially prone to attacking betta fish, as well as other fish that inhabit the upper reaches of the aquarium such as gouramis.
Even if the situation looks fairly peaceful during the day, attacks may happen suddenly at night. You’ll normally see signs of injury on your betta fish if an attack has occurred.
Betta fish will usually sink when they die, but floating is also possible.
Remember, if you find your betta fish floating, it doesn’t necessarily indicate death – but it does always mean some sort of serious illness at the very least.
If your betta is hanging around at the top of the tank rather than floating, check out my dedicated article to find out what could be the issue here.