White spot is caused when a protozoan attacks and attaches itself to a fish's body, fins, and gills. The white spots that appear look like grains of salt or sugar, but each one is actually a tiny parasite. They are very damaging to the fish and can cause breathing and mobility problems and even death.
Once the parasites are established in an aquarium, it is difficult to control the infection because they reproduce quickly. If not controlled, there is a 100% mortality rate of the fish in the aquarium. White spot is very contagious. When one fish in a tank gets sick, it won't be long before the rest of the fish will start showing symptoms.
However, with careful treatment of the aquariums fish, water, ornaments, and plants, the disease can be controlled.
White Spot Disease: Signs, Treatments, and Prevention
Signs
Treatments
Preventions
Swim to surface more often due to difficulty breathing
Antibiotic anti-parasitic medicine specifically for anerobes
Maintain balanced pH level
Protruding eyes
Raising tank water temperature
Replace water with water of same temperature
White spots on fins and body
Malachite green dye
Quarantine new fish for two weeks before introduction
Disoriented swimming
Boil new ornaments and stones before introduction
Diagnosing White Spot Disease
In the first phase of the illness, before white spots appear, infected fish will display some or all of the following behavioral changes:
- scratching against stones and decorative objects (the parasite has crossed the protective mucous membrane that covers their skin)
- disordered swimming
- fins folded against the body
When white spots appear, they are about the size of the head of a pin. The first spots will appear on the fins and can be seen in direct light. As the disease progresses, more spots appear on the rest of the fish's body.
If the gills are affected, the fish may swim to the surface more than usual. This is because they are having difficulty breathing. When the peri-orbital tissues and the eye muscles are affected, the eyeball will protrude.
Treatment for White Spot Disease
The Ich parasite can only be attacked by medications at a very specific point in their life cycle. Medication can work during what is called the "free phase," when the parasite is multiplying. Once the infection phase has begun, medication will not work because the parasites are inside the fish's tissue.
Effective medications include:
- anti-parasitic medicines
- malachite green
Anti-parasitics should be of the antibiotic type, specifically for anaerobes. This way they don't attack the aerobic de-nitrifying bacteria in the aquarium.
Malachite green is a dye known to effectively combat white spot. A disadvantage to this method is that not all fish can tolerate the treatment.