It's no secret that from year to year the ecology of not only our country, but the whole world, is getting worse and worse. All living creatures appear previously unknown diseases and mutations. Fish is no exception. And the spread of disease in fish is becoming a global problem.
Earlier in our articles, we already talked about parasites and diseases of fish.
How do certain diseases appear in wild waters? – the answer is simple – birds! When migrating from one region or country to another, migratory birds bring all kinds of infection to the once cleanest (from parasites and diseases) regions.
We proceed directly to our topic.
Postodiplostomosis – this is the name of this fish disease! Surely, every angler more than once noticed black dots on the caught fish. As a rule, they are located on the scales, on the fins, belly and gills of the fish. Sometimes the fish has one, two black dots, and sometimes the whole body is strewn with black dots. This ailment is found in many fish. Most often it can be found in: bream (forest bream), silver carp, chebak, roach, carp, rudd, perch and many other fish species.
How is this disease transmitted from birds to fish? – The fish becomes infected through a mollusk broker. The stage of development of the disease looks like this: Bird-Mollusk-Fish.
Image source: Veobitskaya I.N., Guseva N.V., Laptev V.I., Musselius V.A. '' Major diseases of pond fish
The causative agent of this disease is a parasitic worm. As a rule, the length of this parasite ranges from one to one and a half millimeters.
The most interesting thing is that this parasite has nothing to do with black spots on fish. This worm parasitizes and develops in the intestines of birds and lays eggs there, as a rule, herons are the main carriers.
Then the eggs of this parasite enter, together with the feces of the bird, in a reservoir where it enters the next link in the chain – the mollusk. The next stage of development takes place in it – asexual reproduction of the larva. However, this is a completely different larva with a different body structure. The name of this larva is cercaria (or metacercaria).
Here they are, precisely, are the cause of the appearance of black spots on the body of the fish. To be more precise, these black spots are cercariae. When their victim enters the body, they penetrate the muscle tissue of the fish and form a kind of capsule there, which, in turn, releases a black pigment.
We examined the name of this disease and how the entire stage of development of black spots on fish goes.
Consider whether black dots on fish are harmful to humans.
Often, parasites, while in the body of the victim, poison it with the products of their vital functions. As for cercariae, they do not emit substances harmful to humans. And you can eat such fish, BUT! The fish is infected and it still poses a danger to humans. If you violate the technology of cooking fish, you can get a helminth infection.
However, if you follow the technology of cooking fish, then the infection with parasites is reduced to zero.
Tip: If you cook the ear, then you need to cook until the fish is completely boiled. If frying, then a crispy yellow crust should be on the surface of the fish. And you need to salted strictly according to the instructions (freeze for at least a month, soak in salt for at least 7 days). Raw or slightly salted fish should not be eaten.
All these tips rule out the viability of various parasites.
But still, some anglers advise to dispose of the caught sick fish and not eat it in order to protect themselves and their relatives from infection with helminth infections.
Thank you all for your attention! No tail, no scales, anglers!