Why does my fish look bent?

You may ask, why does my fish look bent? One of the many reasons why your fish might appear bent is because of the disease they are suffering from. Commonly known as fish tuberculosis or acid-fast disease, this disease can cause fishes to have a bent spine. 

If you have multiple fishes, living with your bent fish, the best way to save other fishes from getting fish TB is to put the infected fish in a different tank to quarantine it. If you do no remove it instantly and do not take proper care, it might eventually die and there is a high chance of other fishes getting infected.

However, some other factors that cause your fish to bent are hereditary, injuries, environmental pollution, parasitic infection, etc. This article will discuss in detail how to identify a fish suffering from different diseases and if there is a way to treat them.

Factors behind your fish looking bent

If you have pet fishes, having a bent fish makes your aquarium look imperfect. Moreover, a diseased fish also might infect other fishes and eventually cause all of them to die. Although there is a chance that your fish have a bent spine due to hereditary factors, or any spinal damage during embryonic development, you should make sure that it is not suffering from any disease. 

Here is a list of factors that discusses in details why your fish might look bent:

Decompression sickness:

Some fishes also get bent while capturing. It happens because the fishes experience a sudden change in barometric pressure in the surrounding environment. When the fish experience the changed pressure for a long duration, it suffers from barotraumas. This syndrome of the bent spine is called decompression sickness.


Just like humans, fishes suffer from scoliosis as well. It is one of the other reasons your fish might have a bent spine. It is most common in the adult female guppy. If you have a female guppy who just gave birth, you will notice them suffering from progressing scoliosis due to abdominal pressure. 

Scoliosis in fishes can also form during the larval stage. Whether it appears in the fry stage or the adult female guppy, this disease does not get any better for them. Even if it does not progress over time, the disease affects the quality of life your fishes may lead. 

  • Water pollution: Along with killing a huge number of marine life and affecting fishes and other aquatic animals’ lives, water pollution is another reason for the fishes to have a bent spine. Polluted lakes, since it is an enclosed space, can have a high amount of selenium in it. Long-term exposure to selenium could also cause scoliosis and lordosis in fishes. 
  • Vitamin deficiency: If you have collected your ornamental fishes from a farm, there is a high chance that they have suffered from Vitamin C and Vitamin E deficiency. Along with the vitamin deficiencies, lack of amino acids in their food could cause them to have a bent spine. 
  • Tuberculosis: Another one of the most common diseases causing fishes to have a bent spine is Fish TB. When the fishes are infected with Gram-positive micro bacteria, it would cause them to have a bent spine. Common fish types that are mostly infected by tuberculosis are black mollies, gouramis, neons, and other tetras, etc. 

What symptoms should you look?

If your fishes did not have a bent spine from its birth and have only recently started developing it, you must immediately put it in a different tank and quarantine it. When there is not, TB might start infecting other fishes. If you believe you are too late to remove it and not sure whether it has infected the other fish, look for certain symptoms. 

Some of the major giveaways to determine whether the fish is suffering from tuberculosis are bulging eyes, loss of fin and tail, lethargy, skin inflammation, etc. Fish TB takes time to show up in fishes, so it is always a good idea to keep a close eye on them. 

Sometimes, it may even take up to years for the fishes to appear bent. So if you can look for the symptoms and diagnose them in early-stage you can treat them back to health. 

Reasons for fish to suffer from scoliosis

Another reason why your fish might be bent is because of scoliosis. Some of the major factors for a fish, to suffer from scoliosis are inbreeding, bad diet, hereditary factors, etc. To avoid scoliosis, always keep an eye on what you are feeding your fish. You might feel like feeding them dry food would be a good idea.

However, remember that some fish are omnivores. So they might not get all the necessary vitamins and minerals from dry food. You must do prior research before bringing pet fishes. So, that you can take proper care of them. 

Also, there is a chance of you overfeeding your fish, which leads them to suffer from scoliosis. A well-balanced diet is extremely important for your fish to lead a healthy life. If you have little to no knowledge on how to help your fish live a long and healthy life, you can always visit pet stores for more information.

Taking preventive measures

To avoid any kind of disease it is always advisable that you take some preventive measures. Here is a list of things you could do to ensure your pet fishes a long and happy life:

Clean the water regularly

It should be a no-brainer, however many people forget to clean their aquarium water regularly, causing their fishes to be infected with different diseases. 

  • Water quality: Along with water change, you should also maintain good water quality for your aquarium. Most tropical aquarium fishes survive best when the water pH level is somewhere between 6.8 to 7.6. However, it may differ depending on the fish you have.
  • No overcrowding: Just because you love collecting varied species of ornamental fishes does not mean you could put them all in one aquarium. Overcrowding makes the spreading of various diseases easier. Along with low oxygen and a high level of ammonia and nitrite, an overcrowded aquarium could cause a ruckus among the fishes. The fishes might become aggressive.
  • Quarantining fishes: If you buy new fishes, make sure that you quarantine them for at least a month before allowing them to be near other fishes. 
  • Closely monitor: Monitor all your fishes regularly so that you can spot any difference in their health and looks to determine if they need treatment or need to be quarantined. The best way to avoid any diseases is to prevent their spreading at an early stage. 

So, now you know why your fish might look bent and how to help them if they are suffering from any diseases. If you are too late in diagnosing their disease, the only thing you could do is euthanize them. As a pet owner, it is the hardest decision you will have to make. Therefore, it is better to keep an eye out for your fish’s health.