Ich (Ichthyophthirius multifiliis) or commonly called “white spot disease” is the most prevalent and persistent disease in both freshwater and saltwater fish. People who raise and farm fish or who have them as pets often encounter this disease. Without the proper action and treatment, ich can cause serious problems in fish and can result to their deaths. Knowing and understanding ich and how it can be prevented and treated can help owners combat this disease.
What is Ich?
Ich comes from the protozoan Ichthyopthirius. A fish with this disease has 1mm white spots that appear on its body, fins and gills. These white spots hold encysted parasites that cause fish to behave and act differently. It is hard to say where ich protozoans come from, but they are introduced to a pond or aquarium through new fish or piece of equipment that has been in an environment infected with ich.
Others also believe that stress causes ich. Unhealthy and stressed fish are more prone to it. While water temperature, improper diet, and poor water quality cause stress, one of the factors that increase stress is the handling and delivery of fish. The process of moving fish from its origin (either the wild or farm-based) to the wholesaler, then retailer, then its new home is very stressful and can result in ich.
How Do You Identify Ich?
A person can check if fish are infected by scraping a white spot sample and placing it under a microscope with a few drops of water. A mature parasite is dark, moves by tumbling, and has a large horseshoe-shaped nucleus. Less mature parasites are smaller and more translucent.
What are the Physical Signs of Ich?
As mentioned earlier, the defining characteristic of this disease are small white spots on a fish’s skin and gills. These white spots damage fish tissue, irritate the skin and secrete mucus. Ich often leads to skin loss and ulcers and adversely affects the ability of fish to breathe and swim in water. It can leave wounds and damage a fish’s gill, making it hard for a fish to get oxygen from water. It is no wonder why a lot fish with this disease die.
What are the Behavioral Signs of Ich?
Aside from the white spots, ich can be identified through abnormal traits and behaviors. These include:
- Loss of appetite or refusal of food
- Labored breathing
- Rubbing or scratching against fixed objects
- Swimming near the surface
- Resting on the bottom
- Lack or no sign of schooling (for schooling fish)
Ich-infected fish behave differently from healthy fish and all of these emphasize how harmful the disease can be.
How Do You Prevent Ich?
The best way to combat this disease is to prevent it. Once fish are infected, owners have to treat their pond, tank or aquarium and this entails a lot of time and work. Prevention is easier, simpler and cheaper than treatment.
The basic principle in preventing ich is keeping fish healthy. Providing the proper living conditions for fish such as a clean aquarium setup, the right water parameters, and quality food and nutrition can keep fish healthy. The tank and aquarium water should regularly be checked and cleaned. Owners should maintain the right temperature, pH and ammonia levels to avoid stress and the outbreak of the disease. Feeds and food should properly be stored. It is also important to have enough space for all of the fish in the tank or aquarium. This minimizes aggression among the inhabitants and helps reduce and avoid stress and disease.
Owners also have the responsibility of buying the right kind of fish and equipment. Since moving fish can cause a lot of stress, it is best to buy fish from a direct source – preferably a wholesaler or a farm instead of a retailer. Owners should always examine the fish for any signs or symptoms of diseases. They must always check the aquarium or tank to see if the fish lived with dead or diseased fish. Owners should place newly bought fish in a quarantine tank and observe them for 2 weeks before introducing them to their new home. It is better to be cautious than to risk having all the fish infected.
How Do You Treat Ich?
There is only so much that owners can do. Even if they do everything to prevent the disease, sometimes, fish still get infected. Luckily, there are different ways of treating ich.
Ich parasites are affected by temperature. Heat can be used to accelerate the parasites’ development and eliminate them. The tomite stage is the stage when parasites break away from the fish’s body and fall to the bottom of the tank or aquarium. During this stage, “tomites” multiply and swim around to find a new host. Tomites can only survive for 48 hours without a host or a fish. Beyond 48 hours, they die.
To ensure that the heat treatment is successful, owners can move fish to another tank, raise the temperature and wait for 2-4 days for the parasites to die. The owners should also treat the tank that the fish moved to; otherwise, the fish risk contaminating the first tank. While heat treatment is very effective, it can only be used to treat a contaminated tank, not the ich-infected fish per say.
Another way to treat ich is by using chemical treatments like formalin and/or malachite green. These also target parasites in the tomite stage. While both formalin and malachite green are effective, they can also be toxic to fish if not properly used. Formalin can turn into paraformaldehyde if it is left alone or stored for long periods of time. White precipitate in a bottle of formalin shows this transformation to paraformaldehyde.
Meanwhile, malachite green may be too harsh and strong for fish like piranhas, neons and sunfish. It is recommended to use lesser amounts for these fish and other sensitive species to avoid stress and distress. Chlorine can also be used to treat ich. It can remove ich parasites in other stages and can also heal the cysts caused by these parasites, although it may take a couple of weeks.
Although ich is a common fish disease that causes a lot of problems for fish and fish owners, the disease can be treated and avoided. Owners need to keep their fish healthy and to be ready in case their fish catch ich.