The swim bladder is a unique organ in fish that helps them maintain their balance and helps them to keep afloat in the water. Although all fish with swim bladders can theoretically get swim bladder disorder, goldfish seem to get it the most, according to “Freshwater Aquarium Problem Solver” (TFH Publications; 2006.) If the swim bladder is not functioning properly, this could prove fatal for the goldfish unless actions are quickly taken.
Goldfish are not found in the wild. They are a domesticated fish bred drom wild Asian carp. Humans have selected for features like color and fin length that may kill off such fish in the wild. When the proper color was achieved, breeders then tried for changes of common goldfish into fancy goldfish. These features include bulbous eyes, bubble-shaped eyes, bumps on the head, very long tails, lack of a dorsal fin (as seen in the lionheads) and a very round body. These unusual body shapes may make fancy goldfish more prone to swim bladder problems than the common goldfish.
A goldfish with any type of swim bladder disorder will have trouble swimming normally. It may float but still breathe and try to swim on the tank surface, lie on the bottom of the tank, swim in circles or even swim upside down. The goldfish may be swimming slightly on its side at a slight angle or even a 90 degree angle to the top of the tank.
Douglas A. Thamm at Net Pets.com notes that goldfish that swim leaning slightly to one side but otherwise act normally do not have swim bladder disease, but may have other illnesses. These fish should be placed in an isolation tank or at least observed carefully.
There are many causes of swim bladder disorder in goldfish ranging from constipation to inner ear infections. Other causes are thought to be poor water quality, a thickening of the swim bladder itself due to a bacterial or viral infection and extreme old age.
When a goldfish is constipated, the digestive organs press down on the swim bladder, flattening it. Food can also become blocked in the duct that allows to fish to be able to inflate or deflate the bladder.
Treatment should include withholding all dry foods just in case of constipation and a partial water change in case the swim bladder problem is due to poor water quality. The water in the tank should be between 75 and 80 degrees Fahrenheit. Sudden rises and drops in water temperature will stress the already ill body of the fish. One of the most effective treatments, according to Net Pets.com, is to place one canned, thawed frozen or mashed fresh green pea into the tank as the goldfish’s sole source of food.
In extreme cases, the fish may need an operation to open a hole in the swim bladder or to remove part of it. However, that’s often not practical for very small goldfish or very old goldfish, but it may help very large pond goldfish.
Although swim bladder disorder is not thought to be contagious in goldfish, other tank mates may harass the sick fish or eat all of the medicinal peas before the sick goldfish can. This is why it’s best to place a goldfish in a tank all by itself. Depending on the size of the goldfish, a five to ten gallon tank with a filter, air stone, adjustable heater and a place to hide. Gravel and elaborate decorations are not necessary. If the tank is small, then be prepared to do partial water changes every day.
Place the goldfish in a hospital or isolation tank with at least two inches covering the top of the dorsal fin (if the fish has one) and the fish may have a better chance of a full recovery, according to “Freshwater Aqauriums For Dummies.” Those fish known to be suffering from an infection need to be treated with a wide specturum antibiotic availbale from pet stores, aquarium supply shops and sometimes veterinarians.
“Freshwater Aquarium Problem Solver.” David E. Borichowitz. TFH Publications; 2006.
“Freshwater Aquariums For Dummies, 2nd Edition” Maddy Hargrove & Mic Hargrove. Wiley Publishing; 2006
Net Pets.com. “Way More Than You Ever Wanted to Know About Swim Bladder Disease.” Douglas A. Thann. http://www.netpets.org/fish/reference/freshref/swimbldr.html
National Fish Pharmaceuticals. “Swim Bladder Disorders.” http://www.fishyfarmacy.com/fish_diseases/swim_bladder.html