The white spot disease can affect the whole population of the aquarium.
It is contagious and can be fatal, for that reason it is important to detect it and to treat it before it is too late.
To detect the disease early, you should pay attention to the first symptoms that the fish can present.
Before the white spots appear, you will see changes in the behavior of fish.
If the fish scratch against the stones or objects in the aquarium or swim quickly, are signs that something is wrong.
It is also common that they keep the fins against the body, or they stop eating.
If the fish have been attacked by the disease, you will see the white first spots in the fins.
They appear firstly in the caudal fin, which can be seen against the light.
They are of the size of the head of a pin.
If the disease progresses you will see more and more big spots, like grains of salt on the body of the fish.
The disease is caused by a parasite that feeds from the body fluids of the fish.
The spots are the reaction of the immune system trying to stop the infection (when the parasite penetrates in the skin), encysting the parasite with a layer of epithelial cells.
The disease can affect the fish gills.
If this happens, the fish will have difficulties to breathe.
Other bacteria can take advantage of the weakness of the fish, attacking it through the lesions that the parasite causes.
This may further aggravate the problem and can lead the fish to death.