White spot disease in fish often goes by the name of ich, an abbreviation of the scientific name Ichthyophthirius multifiliis, it is also referred to as marine white spot diseases (cryptocaryon-irritans). This disease can be deadly to fish, so it’s important to do everything you can to prevent your fish from developing it.
White spot disease is one of the most common fish diseases, and it can affect all kinds of fish in both freshwater and saltwater. While white spot disease isn’t harmful to humans (which makes it easier to treat), it can be fatal to fish if left untreated.
White spot disease (Ichthyophthirius multifiliis) has been affecting fish in freshwater aquariums for decades, and it can be a serious problem when you’re trying to keep your fish alive and healthy. Fortunately, with the right approach, you can prevent your fish from getting sick from this condition and protect their health throughout their lives.
To learn more about how to treat white spot disease in fish, check the below guide!
What is white spot disease?
White spot disease is an infectious, parasitic disease of fish that has been a problem for decades and continues to plague aquarium hobbyists. Though its scientific name is cryptocaryon irritans, it’s commonly known as white spot disease because of several small white spots that appear on infected fish. White spot infection is difficult to cure and can kill a healthy-looking fish within 48 hours.
It can also spread quickly through your tank and kill all of your fish if you don’t treat it immediately after symptoms are first noticed. Even worse, there’s no way to tell if your tank is infected until symptoms are present—it takes between seven and fourteen days after exposure before any signs of disease show up.
This makes preventing new outbreaks vital; by knowing how to prevent white spot infections, you give yourself a fighting chance against one of the most common diseases among tropical freshwater aquarium fish.
What causes white spot disease?
White spot disease can be caused by a protozoan called Ichthyophthirius multifiliis (Ich). It is a common ailment that many fish owners will experience at some point during their fish-keeping hobby. Understanding what causes white spot disease can help prevent its recurrence or spread to other aquariums and fish.
An outbreak of white spot disease typically begins with small whitish spots on one or more fish, usually near fins and body parts where they come into contact with water.
White spot disease is caused by a tiny parasitic copepod (Parvilucifer sp.) that enters your fish through their gills and migrates to their skin. The parasite takes on an appearance similar to a tiny white grain of rice and embeds itself deep under your fish’s skin, where it thrives on fish tissue.
While large numbers of these parasites can be deadly for smaller species like livebearers and guppies, they generally won’t have any effect on full-grown adult fish.
Over time, however, these parasites continue to multiply until they cause severe stress to your fish. Fish with a heavy infestation will scratch themselves against objects inside the tank or swim in circles until they grow fatigued—often leading to death from starvation or illness.
Symptoms of white spot disease in fish
White spot disease is a fungal infection that most commonly affects fish from saltwater aquariums. In freshwater aquariums, it’s referred to as ich or ick.
If a fish has white spot disease, you may notice small white spots on its body, fin or mouth. You may also see red or brown marks on its skin, and observe discoloration of affected areas. As it becomes more advanced, white spot disease can cause lesions that develop into open sores and rashes.
In advanced cases of infection, you might even notice crusty deposits around your fish’s eyes or mouth. If a fish is infected with white spot disease, it will have difficulty swimming and may experience weight loss as well as behavioral changes. Gills that appear to be covered in cotton are another symptom of white spot disease.
The severity of these symptoms depends on how far an infection is; if a fish only has mild discoloration, for example, then it should recover within two weeks with proper treatment.
White spot disease in fish treatment
It is important to consider the complex life cycle of Ich when treating it. Most treatments for Ich only target the free, feeding stage of the parasite (trophozoite), not the encapsulated form in which the parasite divides. This results in a lengthy or two-step treatment, the length of which depends on the system’s temperature. The production of 1000 offspring by one trophozoite in 77 degrees F water only takes 3-6 days.
However, at 59 degrees F, the process can take up to 10 days. When the water gets colder, it takes longer for the life cycle to complete. It is important to keep this in mind when deciding how far apart to space your Ich treatments.
It is common for outbreaks of Ich to occur in the spring when the weather starts to warm up. Because there is more tissue for the trophozoites to feed on, fish stocked at higher densities will develop outbreaks faster. Symptoms of Ich include white spots on the skin and/or gills. The general symptoms of sick fish include appearing to be sluggish, sitting on the bottom of the tank, not eating much, or having reddening of the fins.
When the encapsulated form is observed whirling under a microscope, a definitive diagnosis can be made. There may be some bruising along the side of the fish due to flashing (scratching) and objects scratching their bodies.
Treatment options are available, but you should consider treating at least twice or continuing treatment for at least 1.5 life cycles. There are a number of possible treatments, including formalin, formalin/malachite green, copper sulfate, or salt. Several commercial products are available that treat Ich specifically.
If you are adding something to your tank, make sure the ingredients are checked properly. Keep in mind that copper is toxic to ALL invertebrates and salt can kill freshwater plants.
How long does white spot take to clear?
The length of time it takes to cure white spot disease depends on a number of factors, including how old your fish are, what treatment you’re using and how well you manage your tank. It can take several weeks for minor symptoms to clear up, but treatment may take several months depending on your specific situation.
In any case, if fish appear healthy at week 2 or 3, it’s a good sign that they won’t need further treatment. This is especially true if you treat them with saltwater; unlike freshwater treatments, which often involve copper sulphate (which is known to cause liver failure), saltwater treatments don’t usually cause serious side effects.
If you do experience an issue with toxicity, soak the affected fish in freshwater for 20 minutes and then monitor them over a 24-hour period after reintroducing them into their original environment; if there are no negative reactions, they should be fine.