Parasitic worms are organisms thatable to penetrate into other living beings and live at their expense. There are a huge number of them, but recently, American scientists have become especially interested in worms of the species Anisakis simplex, which are also known as "herring worms." These creatures first infect marine fish, and when dolphins and whales eat them, they begin to parasitize with might and main inside large mammals. Recently, American scientists found that between 1962 and 2015, the number of fish infected with worms increased by 283 times. The question arose - why did the parasite population so sharply increase and why are they dangerous for humans and animals?
The publication shared the answers to these questions.ScienceAlert, citing the scientific journal Global Change Biology. Scientists learned about the increase in the population of parasitic worms Anisakis simplex when they studied data from 123 scientific papers. If you believe the information found, in 1962 the number of fish infected with worms was hundreds of times smaller than in 2015. This is pretty scary news, because worms that enter the human or animal body can cause dangerous diseases. Herring worms described in the scientific work, for example, cause a disease called anisacidosis.
Anisacidosis - a disease caused by parasitic wormsAnisakidae family, to which Anisakis simplex belong. Her symptoms include abdominal pain, nausea, vomiting, fever, and diarrhea. When complicated, the disease causes damage to the intestines and internal bleeding.
Worms in fish
According to scientists, the parasitic worms Anisakissimplex affects almost all fish, including herring, cod, perch and salmon. Since these fish are often used raw for sushi, the risk of human infection with parasites is always high. However, Chelsea Wood, an expert on water and fish resources, believes that people can still eat their favorite foods and not worry. The fact is that when preparing sushi, the fish is carefully checked for the presence of parasites. In addition, while cooking other dishes, the fish is cooked in the oven, and at high temperatures, the worms simply die.
Only dolphins and whales don’t know how to cook,therefore they eat fish raw, along with parasites. Inside marine mammals, herring worms up to 6 centimeters long curl up and brazenly take away vital energy from animals. If there are a lot of worms, infected dolphins and whales can eventually die. The whale population in the world is still fine, but there are dolphins on the planet that are on the verge of extinction. For example, the so-called Hector dolphins (Cephalorhynchus hectori) today only 7,000 individuals remain.
Reproduction of parasites
One would suggest that parasiticthe worms began to breed actively due to global warming. But Chelsea Wood believes that the reason for the increase in the herring worm population is that whale hunting was banned in the United States and many other countries in 1972. The population of huge marine mammals began to recover, and with an increase in their number, the number of parasitic worms increased.
And if the reason for the increase in the number of parasitesconsisted in global warming, not only Anisakis simplex, but also other worms would be engaged in active reproduction. Researchers have found that the population of parasites of the species Pseudoterranova, which affect fur seals and other pinnipeds, has not changed much since 1962.
There are many dangerous worms in the world. They can penetrate our bodies along with meat and settle in the brain. Worms can also live inside our eyes.
What is the result? Rare species of animals today die not only due to climatic changes, but also in the form of parasites. In addition, given the results of the study, sushi lovers should be more careful, because the risk of infection with worms, although low, is still there. Well, in protecting animals, it turns out that there can be negative consequences - the ban on whaling has caused an increase in the number of parasites. How to solve this problem, alas, is not yet clear.