Swim Bladder Disease in Tetras

Tetras require warm water between 75 and 78 F to maintain health.

Tetra is a generalized term for a variety of small colorful fish that have become very popular with freshwater aquarium enthusiasts. These fish are originally from the Amazon River in South America. They require soft water with a pH around 6.8, and temperatures between 75 and 78 F. When their conditions do not fall within this range tetra fish are more susceptible to diseases, such as swim bladder disease.

What is a Swim Bladder?

This fish regulates depth with its swim bladder.

The swim bladder is an organ located in the middle of the tetra's body cavity. It is composed of two, equal-sized compartments. By adjusting the amount of air on each side the tetra can control its depth. This method allows the fish to drift at various depths and conserve needed energy.

Symptoms

This goldfish is demonstrating one of the first symptoms of swim bladder disease.

When a tetra is afflicted with swim bladder disease, there will be a visual change in its swim pattern. The fish may struggle to swim upright, or may turn upside down or onto its side. This is a direct result of its inability to regulate the air within the swim bladder.

Common Causes

The narrow body of a tetra can result in an unbalanced swim bladder.

Swim bladder disease is often a result of breeding and can be a genetic condition. A tetra who recovers from swim bladder disease will commonly experience a relapse. The narrow body of the tetra makes it more susceptible to a malformed or uneven swim bladder. Another cause of swim bladder disease can be bullying from other tank mates. In any case, swim bladder disease is not contagious.

Other Causes

When carrying eggs, the female may experience pressure on the swim bladder.

If the tetra fish is a female, another issue that may cause swim bladder disease is spawn binding. In this case, the female tetra is having difficulty passing her eggs. Careful removal of the eggs will relieve pressure from the swim bladder. Working your fingers down the side of the tetra's abdomen will encourage a release. Another cause of swim bladder disease may be constipation.

Cures

Always use specially formulated aquarium salt for salt baths.

The best way to cure swim bladder disease is to adjust the tetra's environment. Make sure the temperature is within the proper range and the pH is stable. Remove any tank mates from the aquarium that may be bullying the tetra. If this does not yield results, a salt bath can be used to encourage recovery. Add 1 tbsp. of aquarium salt for every 10 gallons of water. Repeat this monthly to maintain health.

References

• "The Simple Guide to Freshwater Aquariums"; David E. Boruchowitz; 2009
• "Tropical Freshwater Fish"; David Alderton; 1997
• "Encyclopedia of Aquarium and Pondfish"; David Alderton; 2005