Myxosporidia

Mixosporidia are parasites characteristic of fish. They do not always harm their owners, but their presence in large quantities can provoke fish to develop serious diseases.

For the human body, myxosporidia are not dangerous.

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Type of myxosporidia

Miksosporidii have many varieties that affect the fish, depending on their species. Fish are infected with protozoa by swallowing their cysts.

The most susceptible to infection of fish of the flounder family, then on the list of myxosporidia are found less often:

• sem. Flounder;
• sem. Rocket engines;
• sem. Gadoids;
• sem. Terrugovyh;
• sem. Chanterelles;
• sem. Herring;
• sem. Scorpion-like;
• sem. Cephalic;
• sem. Salmonids;
• sem. Carp;
• sem. Belyudyugovyh and others.

Some varieties of myxosporidia are found in the cartilage, others in the outer cover or in the layer of connective tissue. You can observe parasites in the muscle tissue of fish: they look like small cysts. In frozen fish, spores can remain viable for many months, while their numbers remain unchanged. After the death of the host fish, the infected musculature passes through the histolysis stage, after which it softens, becomes jelly, resulting in the appearance of a viscous homogeneous substance. Therefore, the quality of such fish is constantly deteriorating.

The life cycle of myxosporidia

How is the cycle of myxosporidia development going on? How does the parasite appear in the body of fish?

Miksosporidii spread spores, which are the main link representing the life cycle of myxosporidia.

The formation of spores occurs in the endoplasm of parasites. Depending on the size of the plasmodium, they can form from two to several thousand spores.

The structure of Myxosporidia is very complex and at the same time very peculiar. Externally, the dispute is covered with a two-folded dense shell. The valves have a visible joint - the seam. On this site the valves touch each other, resembling two clock lenses, closed at the edges. The valves can have different shapes, in addition, in many cases they have processes of different configuration and length.

In the middle of the valves on the posterior surface of the spore is a small amoebic embryo, which, as a rule, has two cores. In the front part (or along the seam boundary) there are a pair (or 2 pairs) of stinging capsules. Such a capsule is a kind of bubble with liquid contents, covered with its own layer of the shell. Inside is a spirally wrapped oblong thin thread. Its length can many times exceed the total length of the spore. Such a thread is of great importance in the defeat of fish by myxosporidia.

The development cycle of the dispute has many difficulties. Six nuclei are involved in the formation of each structure, of which 2 form amoebaids, 2 more form flaps, and the two remaining contribute to the formation of stinging vesicles.

Ripe spores can enter the water body in various ways:

• cavitary myxosporidia are secreted through the intestine and kidneys;
• tissue miksosporidii - with violation of the integrity of the cyst and the formation of ulcerative surfaces.

Some types of myxosporidia relieve spores only after the death of the host, for example, parasites that live in cartilages and nerve fibers.

In the case when the spore swallows the fish, thanks to the digestive enzymes, the spiked strings are released and enter the intestinal wall. There, the spores are fixed in the host's body, after which the valves open along the seam border, the amoebic embryo leaves the spore and penetrates into the tissue unhindered. Subsequently, from the tissue to the tissue, the embryo reaches the organ that is most suitable for this type of myxosporidia.

The described life cycle of myxosporidia is very peculiar and does not repeat the cycles of development of other sporophores. The structure of structures is also very characteristic.

Miksosporidii in humans

When the dead fish decay, the spores go out and find themselves in a pond where they ingest a healthy fish. Miksosporidii are a common cause of disease and mass death of fish. Parasites are often found in edible fish, which is the reason for rejecting such fish products. However, spores (capsules) are easily removed from the carcass of fish, which can later be quite suitable for eating. When examining the capsule composition in a microscope, it is possible to observe the inherent myxosporidia spores. These protozoa in any form can not parasitize in the human body, as well as in the organisms of mammals and birds. For this reason, myxosporidia do not pose a danger to humans.

Treatment of myxosporidia

Despite the fact that myxosporidia are considered the causative agent of serious diseases in fish, infection by them at the present time does not lend themselves to certain methods of treatment. It is recommended to fight with myxosporidiosis, using only preventive measures in conditions of fish farms, ponds or fisheries. Of course, myxosporidia cause great damage to the fishing industry, adversely affecting the commercial appearance and taste of fish. But, nevertheless, there is still no special scheme for treating myxosporidia.

Prevention myxosporidia

Prevention miksosporidii in the conditions of fish farms is aimed at eliminating fish from the water affected by myxosporidia, cleaning and summering. Use the full drainage and cleaning (in the warm season) of the bottom of the reservoir from the flora, roots, etc., put in order the hydraulic structures, disinfect the tributaries and channels. Under the influence of solar radiation, disinfectants and drying, death or loss of viability of myxosporidia occurs. In addition, during cleaning, the bottom of the reservoir is saturated with oxygen, mineralization of organic substances occurs, and the natural fish productivity of the reservoir rises.

In view of the safety of myxosporidia for humans, preventive measures when eating contaminated fish are not established.