Ichthyophthirius

Ichthyophthyriasis, better known as Manka or White Spot Disease, is one of the most well-known diseases of aquarium fish. In this case, “known” does not mean common.

It is easy to diagnose, which is why the name is often mentioned among aquarists.

The cause of the disease is infection with the microscopic parasite Ichthyophthirius multifiliis, which settles on the body of the fish. Almost all aquarium species are susceptible to diseases. Most common among Mollies.

As a rule, the parasite enters the aquarium with sick fish, live food or decoration elements (stones, driftwood, soil) and plants that were taken from an infected reservoir / tank.

Life cycle

Stage number 1. Having fixed on the fish (skin or gills), Ichthyophthirius multifiliis begins to intensively feed on particles of the epithelium, deepening into the integument of the body. Outside, a white tubercle gradually appears, about 1 millimeter in size – this is a protective shell called Trophont.

Stage number 2. Having collected nutrients, Trophont unhooks from the fish and sinks to the bottom. Its shell is impenetrable and at the same time has the properties of being fixed to any surface, so it often “sticks” to plants, stones, soil particles, etc.

Stage number 3. Inside its protective capsule, the parasite begins to actively divide. This stage is called Tomite.

Stage number 4. The capsule opens and dozens of new parasites (Theronts) appear in the water, which begin to look for a new host to repeat their cycle.

The duration of the complete life cycle depends on the temperature – from 7 days at 25°C to 8 weeks at 6°C.

Thus, in the closed space of an aquarium without treatment, the same fish will be subject to constant infection.

Symptoms

Due to its size, it is impossible to detect the parasite with the naked eye. However, at one of the stages of his life, he becomes noticeable thanks to the same white dots, resembling grains of salt or semolina, because of which the disease got its name.

The presence of small white bumps is the main symptom of Ichthyophthyriasis. The more of them, the stronger the infection.

Secondary symptoms include:

• itching that makes the fish want to rub against decorations
• in case of damage to the gills, there may be difficulty breathing;
• in severe cases, there is a loss of appetite, exhaustion begins, the fish becomes inactive.

It is important to pay attention to the color of the dots. If they are yellow or golden, then this is probably another disease – Velvet disease.

Treatment

The disease itself is not fatal. However, complications caused by damage to the gills often cause death.

If one fish has symptoms, then everyone is sick. Treatment should be carried out in the main aquarium.

First of all, it is necessary to raise the temperature of the water to values ​​uXNUMXbuXNUMXbthat the fish can withstand. The optimal range is indicated in the description of each species. High temperatures will speed up the life cycle of the parasite. The most vulnerable to drug treatment are Theronts, which have just emerged from the capsule and swim in search of a host.

Since the ability of oxygen to dissolve in warm water decreases, it is necessary to increase aeration.

The disease is well studied, easy to diagnose, so there are many specialized medicines.

Medications against Manka (Ichthyophthyriasis)