Why is Your Fish Swimming Upside Down But Still Alive

By Jecinta Muturi @aquariawise

Why is Your Fish Swimming Upside Down But Still Alive

It can be scary when you have a fish swimming or floating upside, and you may only have a little time to save it.

If your fish is swimming or floating upside down but is still alive, it has a problem with the swim bladder, an organ that helps fish regulate their buoyancy. Fish swim this way if the organ becomes damaged or infected.

In some cases, a fish with swim bladder disease may also float to the surface or sink to the bottom, or swim in an irregular, erratic manner.

Fish with mild swim bladder disease may be able to compensate for the loss of buoyancy control and swim relatively normally…

…but fish with severe swim bladder disease will swim upside down, eventually become lethargic and lose the ability to move around the tank.


In case your fish does not have swim bladder disease but still swimming upside down or erratically, it could be due to a variety or one of these (other) reasons:

Water quality issues: Poor water quality can affect a fish’s ability to swim normally. High ammonia or nitrite levels in the water are toxic to fish and cause them to become disoriented or swim abnormally.

Injury: If your fish has experienced an injury, such as a head injury or damage to its swim bladder, it may swim upside down.

Neurological issues: Certain neurological disorders can also cause fish to swim upside down. These disorders can be caused by genetics, infection, or injury.

Parasites: Certain parasites, such as gill flukes, can cause fish to swim erratically and in a corkscrew motion, which you may confuse with swim bladder symptoms (floating upside down).

Swim Bladder in Fish

Swim bladder disease is a condition that affects a fish’s swim bladder, which is an internal gas-filled organ that helps fish regulate its buoyancy, maintain their position in the water and swim properly.

Swim bladder disease can affect a fish’s ability to swim, and the symptoms can vary depending on the severity of the condition. The affected fish may swim upside down, float to the surface or sink to the bottom.

The disease (or disorder) starts when the swim bladder, is injured (physical trauma) or infected.

Poor water quality (ammonia, nitrites) and chemistry (pH and temperature), wrong foods or overfeeding, can also cause or exacerbate swim bladder in fish.

Some (other) common signs include:

Swim Bladder SymptomsDetails
Abnormal swimming behaviorThe fish may have difficulty swimming or may swim upside down or sideways
Floating or sinkingA fish with swim bladder disease may float upside down or sink uncontrollably to the bottom of the tank
Loss of appetiteThe fish may stop eating or become lethargic
Swollen bellyThe fish’s belly may become distended or bloated and eventually make it impossible for your fish to turn (flip over)
Difficulty breathingYour fish may gasp for air at the surface (near the top of the tank), especially when water chemistry or quality is also responsible for the swim bladder disorder

What Causes Swim Bladder in Fish

Gas build-up in the swim bladder can be a symptom of swim bladder disease, but it is not necessarily the cause. The disorder results from infections or physical damage to the swim bladder, a result of:

Overfeeding: Feeding your fish too much, large portions or foods that are difficult to digest can cause the swim bladder to become distended and affect its function. When fish become constipated, it can put pressure on the swim bladder and cause it to malfunction.

Infections: Some bacterial or viral infections, such as Pseudomonas and Aeromonas, can affect the swim bladder and cause it to become inflamed or infected.

Physical trauma: Physical trauma, such as a blow to the fish’s abdomen, can damage the swim bladder and affect its function.

Genetics: Some fish species are more prone to swim bladder disorders due to genetic factors.

Is Swim Bladder Disease Fatal to Fish

Swim bladder disease can be fatal to fish if left untreated. It will gradually cause your fish to float uncontrollably to the surface or sink to the bottom of the tank. It will become hard for the fish to breathe, eat, or avoid predators, leading to stress and making the fish susceptible to other diseases or infections.

If you notice symptoms of swim bladder disease in your fish, such as difficulty swimming or staying upright (floating upside down), seek veterinary care or consult a knowledgeable fish specialist as soon as possible.

With prompt and appropriate treatment, many fish can recover from swim bladder disease and go on to live long, healthy lives.

Can Fish Die from Swim Bladder Disease

Yes, fish can die from swim bladder disease if left untreated. However, the disorder is only a symptom of an underlying injury or infection, and only treating the swollen bladder won’t work.

The fish can go for weeks or months with swim bladder disease but continue administering treatment and offer your fish peas to keep it alive.

If you have tried treating fish with swim bladder unsuccessfully -the condition is not getting better or keeps reoccurring- you should consider humanely euthanizing your fish.

How Long Can Fish Live with Swim Bladder Disease

How Long Can Fish Live with Swim Bladder Disease Fish can live with swim bladder disease for weeks or even months, but it will depend on the severality of the condition and species and health of your fish. Fish with mild cases only causing minor symptoms, such as difficulty swimming or floating to the surface, can be treated with simple adjustments to the diet or environment and recover in 2 to 3 weeks.

However, if you do not put your fish on treatment before the symptoms are severe, your fish could die of swim bladder disease in less than seven days.

Carps, like koi and goldfish, are also more susceptible to the disease and often get recurring attacks, and are less likely to survive a shorter time in subsequent periods.

Poor water quality and chemistry, overfeeding, infections, off-temperatures, and injuries are all causes of swim bladder disease, and your fish is more likely to live longer (and survive the disorder) if all these conditions are treated or resolved.

Can Fish Survive Swim Bladder Disease

Fish can survive swim bladder and live a healthy life if you catch and treat the disease early. Mild cases of the disorders can be treated with simple adjustments to your fish’s diet or environment, depending on what is causing the root cause.

How Do You Treat Swim Blddaer Disease in Fish

If you discover your fish has swim bladder disease, start taking steps immediately because the condition can kill your fish in less than seven days in severe cases.

Here are steps to treat swim bladder disease in fish:

Start by moving your fish into a twenty-gallon quarantine/hospital tank, especially if you have shrimp and snails in your tank, because you may need to treat him with copper-based medicine, which is harmful to critters.

Check your water conditions and quality. Ammonia and nitrites should be zero and nitrate at acceptable levels (20 ppm max).

Keep the water temperature and pH in the range your fish prefers. 72 ° F to 78 ° F (22&deg C to 26° C) is optimal for most tropical freshwater aquarium fish.

Add salt and stress Zyme to the hospital tank to calm your fish down.

— Overfeeding can cause digestive problems in fish and lead to swim bladder disease. So, starve your fish for 3 to 4 days*.

Offer your fish peas once you return to feeding him. Deshell the peas and offer him what is inside without the cover.

You can mix them with flake, but reduce the amount (and frequency of feeding) and feed him smaller, easily digestible portions. Remember to include them in your fish’ daily diet rather than when an issue occurs.

Medicate your fish with erythromycin, API general cure, or seachem safeguard with methylene blue to fight infections, which are more likely the root cause of swim bladder in your fish.

Lower the water level about halfway and give your fish plenty of spots to rest until he gets back to good health.A flotation device, such as a small tank with a divider, can help support the fish and keep them upright while they recover.

— Try netting your fish closer to the surface and leaving him there so he can swim less to get air.

It’s important to note that swim bladder disease can be hard to treat and may take time for the fish to recover fully.

So, If unsure of the best actions, consult a veterinarian or fish expert for guidance.

Why Your Fish is Swimming on One Side

A fish swimming (or floating) on one side or sideways is caused by a positive buoyancy disorder, often swim bladder disease. Try and observe other signs of the illness, like lethargy and lost appetite to isolate and treat the issue.

You may also want to consider quarantining the fish and seeking the advice of a veterinarian or experienced fish keeper who can help diagnose and treat the condition.

Happy fish keeping🐠🐟!

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