Ichthyophthiriosis (semolina) Of Fish

2023 Author: Molly Page | [email protected]. Last modified: 2023-11-27 22:49

Something happened to my fish: as if someone had sprinkled semolina on them

This is ichthyophthiriosis, a widespread disease. It is caused by the ciliate ichthyophthirius multifiliis - an animal consisting of only one cell. Its body resembles an egg, the diameter of which is from 0.5 to 1 millimeter. It is covered with cilia of the same length and thickness.

Ciliates can get into an aquarium with live food, with plants, finally, with soil taken from the reservoir and not subjected to disinfection. In addition, the disease occurs after the purchase of fish, molluscs that lived in an aquarium where there were ichthyophthirii, or algae that grew in such an aquarium.

Ichthyophthyroidism affects all aquarium fish. However, of the viviparous fish, the least susceptible to the disease are guppies with low fins and girardinus, and besides them, goldfish, comets, and shubunkins.

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Outbreaks of ichthyophthyroidism in aquariums are observed all year round, but more often in the spring-summer period, because at this time there is an intensive reproduction of ciliates in water bodies and the possibility of their introduction into aquariums increases. Fish become infected with very small young ichthyophthiri, the so-called tramps.

Regardless of how the ciliates ended up in the aquarium, tramps, whose body diameter is 20-30 micrometers, constantly swim around the aquarium and eventually bump into fish. They immediately attach to it and, using the enzyme hyaluronidase, destroy the epithelium - a layer of closely spaced cells covering the skin begin to penetrate deeply.

Having climbed under the epithelium, the ciliates begin to eat. Their mouth is at the front end of their body, and they swallow nearby cells.

Ichthyophthyroidism

Ichthyophthirius eat and grow and can soon be seen. The fish is as if sprinkled with semolina. How long the ciliates will grow is highly dependent on temperature. If the water temperature is 28-30 ° C, ichthyophthirii grow in four days, at a temperature of 19-21 ° C - in seven days, at 13-15 ° C - in ten to eleven, and at 8-9 ° C - in forty days …

When the diameter of the body becomes limiting, the ciliate destroys the tubercle inside which it is located, is selected from the tissues of the fish, and enters the water.

At first, ichthyophthirii swim slowly with the help of their cilia, but soon they sink to the bottom, to a stone, to any object, stick to them, and a delicate gelatinous membrane - a cyst - forms around them. Immediately after this, the ciliate begins to divide by two many times. As a result, sometimes two thousand small, cilia-covered ichthyophthirii, vagrants, which move, are formed inside the cyst. At a certain point, with the help of hyapuronidase, they dissolve, destroy the cyst wall and end up in water.

Now they need to find fish. If the tramps do not hit the fish in two days, they will die. Those who are lucky start to grow. And the cycle repeats.

The rate of division of ichthyophthirii, as well as their growth in fish tissues, directly depends on temperature. The optimum temperature for the development of ciliates is 25-26 degrees. A decrease in temperature delays the formation of cysts, slows down division, and lengthens the life of stray outside the fish body. This period is also increased by the low illumination of the aquarium.

When ichthyophthirii attach to the body of the fish and penetrate under the skin epithelium or into the connective tissue between the folds of the gills, and this lasts for two or three days, the fish begin to behave restlessly: they rub against the ground and plants, approach the place in the aquarium, where they rise up air bubbles formed during aeration of water.

Later, while the fish gives the impression of being sprinkled with semolina, it swims near the surface of the water, greedily swallows air, more often rubs against the bottom and plants. She stops eating and does not respond to external stimuli. If the fins of the fish are severely affected, they split. If the cornea is severely affected, the fish goes blind.

When ichthyophthirius penetrates under the epithelium, the cells surrounding it form a multilayer capsule in which the ciliate completes its development. When ichthyophthirius settles on the gills, the connective tissue between the folds becomes inflamed, the tops of these folds stick together and a cavity appears, but a capsule is not formed.

Having finished their growth, ripe ichthyophthiri, getting out, damage the surface of the body, disrupt skin respiration. When the gills are damaged, the epithelium sloughs off, which also interferes with normal breathing. It is these changes that cause the fish to behave abnormally. However, ciliates have not only mechanical, but also toxic effects on the fish organism.

Treatment. All fish are transplanted into a separate vessel, it is better if it is completely made of glass. There should be no soil and algae in it.

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Malachite green solution completely frees fish from ciliates. A positive result is obtained by treating fish with basic violet K. With a strong infection, bicillin-5 is used. This drug can also be used to treat fish in an aquarium.

Gradually, the white bumps on the fish's skin will become smaller and smaller. But the treatment must be continued until they disappear completely and even after that for another three days.

In an aquarium where sick fish lived, water, soil and plants do not change, since ichthyophthirii die without fish on the second or third day. For greater safety, the water temperature in the aquarium is raised to 32-34 degrees and kept at this level for two to three days.

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