Among the helminthiases of fish, registered both in the Astrakhan region and in many other regions of Russia, the most dangerous and widespread is postodiplostomosis caused by metacercaria - the larval stage of the digenetic fluke of the trematode (parasitic flatworm). The life cycle of a trematode takes place with the participation of three hosts: the first intermediate - gastropods-coils, the second intermediate (additional) - fish, and the definitive (final) - ankle-footed birds that feed on fish. Sexually mature helminths develop in the intestines of fish-eating birds. Infection of fish occurs mainly in late spring - first half of summer.
The disease is characterized by the appearance of black dots, bumps and spots. Each point is a place in which a capsule with a helminth larva is located. The localization of the parasite in fish is the skin, fins, gills, subcutaneous muscles, the mucous membrane of the mouth, and the cornea of the eye.
More than 60 species of freshwater fish are infected, in our region they are perch, carp, carp, silver carp, rudd, sabrefish, ram, roach, etc. In case of post-diplostomosis disease in fish, the growth and weight of the body, the quality of meat, often this disease leads to deformation body, curvature of the spine, impaired mobility. Due to the loss of the marketable condition, hundreds of tons of fish are sent for disposal, which leads to economic losses. Fish with post-diplostomosis become easy prey for predatory fish and fish-eating birds. The larvae of the parasite are especially dangerous for fry, as they can cause mass death of fry.
So is it possible to suffer from fish?
Yes, you can. Fish meat contaminated with post-diplostomosis is moderately toxic. You should be aware that poorly cooked or not cooked fish not only causes poisoning, but can also be a source of infection for humans and domestic animals with helminths. If the larvae of worms visible to the eye, which are in outwardly healthy fish, after entering the body of humans and fish-eating animals, cause serious diseases.
No treatment has been developed. Prevention and control measures are to break the life cycle of the pathogen. Considering that the development of helminth occurs with the participation of mollusks, the disease of fish can be prevented by a sharp decrease in the number of mollusks in the reservoir. Also, this parasite is a danger to the home aquarium and its inhabitants.