Table of contents:
- Hepatic flukes
- Temporary intermediate host of the hepatic fluke
- The ultimate host of the liver fluke
Last updated 12 February 2020 at 10:54 pm
Reading time: 4 minutes
Flatworms, flukes migrate from one host to another until they find a permanent habitat. To reach the final owner, they have to go through a complex life cycle.
The variety of developmental stages of the hepatic fluke is also striking. From the period when the egg enters the external environment and to the stage of reproduction, which occurs by laying eggs by an adult hermaphrodite marita.
- 1 Liver flukes
- 2 Life cycle of the hepatic fluke
- 3 Temporary intermediate host of hepatic fluke
4 Ultimate host of the liver fluke
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How does the path of development of a trematode to a sexually mature adult, ready for growth and reproduction, take place? And who is the intermediate host of the hepatic worm.
Let's start looking at the entire life cycle from the moment the parasite breeds:
- mature individual marita. The result of cross-insemination within the hermaphrodite is the fertilization process. After that, about a million eggs appear every week. They enter the external aquatic environment with the excretions of animals and people. The final owner of the liverworm suffers greatly, since marita attacks the liver and its cells;
- miradium. It appears under the influence of light. The ciliary larva develops about 17-18 days at a favorable temperature of no more than 29 ° C. In a day, she must find a carrier and penetrate into his body. Usually it becomes a small pond snail;
- sporocyst. Parthenogenetic form, which is formed inside the mollusk by getting rid of the larva from the ciliary cover. In sporocysts, fertilization takes place internally. Tears gradually;
- redia or eggs fertilized by the sporocyst. They multiply in this way several times. But already in the liver of the mollusk. This process can take up to 2 months. After that, larvae with tails appear;
- cercariae. They leave the snail and head closer to the coast, where their further development will continue. The larva gets rid of its tail and sticks to plants. Covered with a dense shell. A cyst is formed;
- adolescaria can be in a cyst state for several months. Then, together with water or plants, it enters the body and intestines of the final owner;
- the hermaphrodite worm marita already has a leaf-shaped body. Length - 3 cm. The larva has an oral and abdominal cavity, it is able to remove the remains of vital activity, it is equipped with a reproductive system.
Temporary intermediate host of the hepatic fluke
Multiple reincarnations and transitions from one stage of development to the next stage provide for both external changes and environmental conditions. Naturally, all this time, the flatworm not only parasitizes, but also adapts.
There are three types of its life cycle:
- in a temporary carrier;
- free larva stage;
- from the final owner.
The intermediate first host of the liver fluke at the larval stage is a small pond snail or a mollusk. Here, the parasites enter the liver and feed until they reach the stage of cercaria, a free larva.
At the stage of adolescaria, the final or temporary owner of the hepatic fluke can be livestock, which is often located near water bodies or cats, dogs. Another final owner of the liver fluke is also able to become infected at this stage - a person. The pathways for penetration are the ingress of water into the mouth or ears when bathing.
The ultimate host of the liver fluke
How does a flatworm manifest itself when it reaches its last habitat. The final host of the hepatic worm in most cases is a human. Except for livestock, which is also not just a carrier and vector of parasites.
How does the process of human infection take place:
- non-compliance with hygiene rules;
- contaminated poorly treated water;
- fish living in freshwater bodies;
- animal meat;
- poorly processed foods that end up on the table from the garden.
And here a new stage of the life cycle begins. First, the worms enter the intestines through the mouth and stomach, where they move to the stage of a full-fledged larva. They migrate to the liver and biliary tract. They destroy the walls and tissues of the liver.
Sometimes they enter the respiratory system, but they quickly die there. After 3 months, they reach the stage of a sexually mature individual and reproduce.