Latin name: Other names: growth impairment, spine curvature Pathogen:
Fish growth slows down,
Scoliosis (bent spine)
Disease manifests itself most often at the larvae or fry stage, more rarely in adult fish. Sometimes spine curvature can be observed in live-bearing females after fry appear, which can be explained by a dramatic change in abdominal pressure. The spine can become curved in any place; sometimes curvature is observed in several places, it can be both vertical and horizontal. As a rule, sick fish will show impaired growth, though they will not exhibit loss of appetite. Scoliosis is fatal only in larvae and several-week-old fry.
Scoliosis is quite a common fish disease, characterized by spine curvature. There is no unanimous opinion about the aetiology of this disease. Some scientists consider that scoliosis results from inbreeding (breeding between close relatives) which causes various mutations in next generations. Others think that scoliosis is a result of the abnormal development of the ovule caused by feeding the female concentrated and unvaried dry food as well as of various traumas at the larvae and fry stages. Other scientists believe that the condition results from the lack of mineral salts or hypoxia. Some have noticed that scoliosis is most commonly diagnosed in the aquaria of selectionists who breed live-bearing species, particularly new species of Guppy. A thorough examination of Guppy produced by selective breeding showed that spine curvature is observed in all cases of breeding between close relatives. It has also been noticed that the rate of young fish suffering from scoliosis is higher in aquaria with low levels of oxygen. Scoliosis is common in overcrowded rearing aquaria and oxygen-poor water caused by feeding fish combined dry food, especially in winter, which often results in bacterium turbidity. Water hardness in such aquaria ranged from 6 to 12 dh, which rules out the lack of calcium and magnesium salts. Aquarists who fed their fish live food, avoided inbreeding and had a wide variety of plants in the aquarium reported only single cases of scoliosis. These observations and scientific data indicate that inbreeding is the main cause of scoliosis.
Potential causes include: an unvaried diet of dry concentrated and combined foods, lack of oxygen wide range of plants, and overstocking. Traumatic scoliosis is occurs very rarely.
How to cure:
There is no known cure for this condition. Affected fish are disposed of.
Avoid inbreeding. From an early age, it is essential to maintain optimal thermal and hydrochemical regimes and provide a balanced diet necessary for the breeding stock. Do not overstock the aquarium and try to prevent traumas, especially at the larva and fry stages. The tank should have enough plants. Add fresh, settled water to the aquarium at least once a week. Water hardness should be only decreased to the level necessary for a particular fish species during spawning, incubation, larvae and fry development.