Why is My Guppy Swimming Upside Down?

Guppies are lively and energetic members of your aquarium are usually a pleasure to keep due to their hardy and resilient physiologies. However, your guppy can get ill, and abnormal swimming behavior may be a sign of a serious condition. If your guppy is swimming upside down, you are right to be concerned.

Your guppy is swimming upside down due to a swim bladder problem. The swim bladder regulates buoyancy and the ability to swim. The leading causes of swim bladder issues are: 

  • Nitrite toxicity
  • Poor tank water quality and bacterial infections 
  • Low Fiber Diet and Overfeeding
  • Other internal diseases.

If your guppy is swimming belly up, you need to address the cause behind the swim bladder issues. Often the reason lies in poor tank hygiene or incorrect feeding practices, and you may be able to cure your fish. Here are some of the most likely reasons why your guppy’s swim bladder is off-kilter.

Two guppies in freshwater aquarium

Swim Bladder Disease and Upside Down Swimming 

The chances are good that your guppy suffers from swim bladder issues if it’s swimming upside down. The swim bladder is essential in buoyancy and balance, and if the swim bladder is affected, your fish will exhibit rather bizarre swimming actions. Here are some of the reasons your guppy may be experiencing swim bladder problems.

Nitrite Toxicity 

Nitrites are a naturally occurring chemical in your aquarium created by bacteria that break down ammonia in your tank’s biological filter. While nitrites are a natural part of a healthy tank’s nitrogen cycle, nitrite levels may rise to a toxic level in your tank. This rise is typically due to:

  • New or damaged biological filters due to overcleaning or interrupted water supply
  • Overstocking of fish for your tank size
  • Overfeeding your fish.

Nitrites affect your guppies’ chlorine uptake in their gills and can create ‘brown blood disease due to methemoglobin. Methemoglobin inhibits the oxygen-carrying ability of the blood, and your fish may suffocate even while in a large area of water.

The changes in oxygen affinity and blood pH cause oxygen to accumulate in the swim bladder, causing buoyancy issues in your guppies.

Signs of Nitrite Toxicity in Guppies:

  • Buoyancy issues such as swimming upside down
  • Inability to rise from the tank bottom
  • Brown discoloration on the gills
  • Signs of hypoxia or air-breathing or surface respiration.

Poor Tank Water Quality and Bacterial Infections

Healthy fish can fight off bacterial attacks due to their natural immunity. In poorly kept tanks with waste accumulation and infrequent water changes, your guppies’ immune system becomes impaired and opens them to bacterial infections.

Guppies are particularly prone to infections caused by a strain of bacteria called Aeromonas which may cause disease in the swim bladder.

Low Fiber Diet and Overfeeding

Constipation is often the contributing factor in swim bladders problems in your guppies. When your fish is constipated, the internal swelling within the digestive tract can compress the fish’s swim bladder and cause buoyancy issues.

However, constipation is also a symptom of swim bladder disease, and swim bladder disease is a symptom of constipation, so you should ensure you investigate the proper root cause of the condition.

The most common causes of constipation in fish re:

  • Poor diets containing insufficient fiber
  • Insufficient exercise. If your tank is too small, your fish may be constipated due to inadequate activity.
  • Overfeeding your guppies. Guppies will continue to eat after they are full so ensure that you feed the correct amount of food for your fish.

Other Internal Disease

When your guppy suffers from an internal disease, their organs may become enlarged and affect the functioning of the swim bladder. The buoyancy issues in your upside-down fish may be a symptom of a deeper underlying problem.

The most common diseases that affect the swim bladder include:

  • Kidney cysts
  • Fatty liver deposits
  • Egg binding in female guppies.

What are the Signs of Swim Bladder Issues?

Swim bladder dysfunction can manifest in several ways, and there are multiple reasons why your guppy’s swim bladder is causing your fish to swim upside down. Typically abnormal swimming behaviors such as inverted swimming are caused by:

  • Abnormal fluid collection in the swim bladder
  • The collapse of the swim bladder
  • Overinflated swim bladder
  • Herniation.

Signs Your Fish has Swim Bladder problems:

  • Swelling of your guppy’s abdomen area
  • Abnormal swimming actions
  • Struggling to maintain a neutral, upright position
  • Loss of the ability to float
  • Sinking to the bottom of the tank
  • Floating on the surface of the tank.

What Is a Swim Bladder? 

The swim bladder is a specialized organ that regulates gas and oxygen balance to maintain its ability to remain afloat at its desired depths. The swim bladder is a membranous sac that contains atmospheric gasses and is found behind the digestive tract and below the vertebrae.

The swim bladder regulates a fish’s buoyancy so that it does not need to invest energy in swimming to keep afloat like some other species like sharks. Studies show that beyond mere buoyancy and equilibrium, the swim bladder also functions as:

  • Sound production
  • Respiration
  • Perception of pressure fluctuations (involved in sound).

Can I Cure Swim My Upside Down Guppy?

Depending on the cause of your swimming bladder issue, the problem may be temporary or permanent. The best way to isolate why your fish has swim bladder issues is through a process of elimination.

  • Check your tank conditions and the chemical levels in your tank, and ensure that your tank is balanced and clean.
  • Ensure that your biological filter is functioning correctly.
  • Ensure your aeration levels are properly balanced.
  • If the problem is bacterial, you may use Epsom salts to treat the bacterial cause.
  • Stop feeding your guppy for two days and increase the water temperature to 78-80°F to inhibit bacterial growth
  • Increase your salt levels in your tank
  • If you feed floating food, first soak the food in water to inhibit air intake while feeding
  • Increase the fiber content of your guppy’s feed.

Closing Thoughts

Just because your guppy is swimming the wrong way round does not necessarily mean that your guppy is going to die. Once you isolate what is causing the swim bladder issues, you can rectify the condition. If the symptoms won’t seem to go away, it is best to consult a professional to treat your guppy.