Power flat worms. What do flatworms eat?

All representatives of multicellular animals are distinguished by the level of organization, characteristic features of vital processes, and are combined into special taxa-types. A total of 7. The type of flatworm is one of them. These creatures have perfectly adapted to the conditions of existence and occupy their biological niche. How does a flatworm feed? Find answers in our article.

General characteristics of flatworms

The name of the representatives of this systematic group was given by the shape of the body. A cross-section of flat worms resembles a leaf or ribbon. For these animals, bilateral symmetry and formed systems of organs are characteristic. The musculoskeletal system is represented by a skin-muscular sac, which consists of a covering epithelium and several layers of muscles. The excretory system consists of thin tubules opening outwards with pores.

The vast majority of flatworms are hermaphrodites, but some can reproduce and vegetatively. In parasitic species in the life cycle there is a change of hosts - the final and the intermediate. The nervous system consists of the central and peripheral parts. But the respiratory organs do not have flat worms and carry out gas exchange through the entire surface of the body.

Habitat

Among these animals there are both parasitic and free-living species, which determines the nutrition of flatworms. They can be found in the seas, fresh water bodies, and very rarely on land in the rainforests.

Parasitic species inhabit the intestines and liver of many animals: cattle, pigs, dogs, cats and even sperm whales. Some dangerous species live in the human body.

Features of the digestive system

Digestive system of flat worms of closed type. It consists of a mouth and an intestine. How is nutrition of flatworms carried out? Nutritional particles enter through the mouth, digested in the branched intestine, and the remnants are also removed through the opening located at the anterior end of the body.

The nutrition of flatworms, which lead a parasitic life, occurs at the expense of the host organism. Such species have no organs of the digestive system. The already digested substances they absorb through the covers.

Feeding flatworms

Worms that live in various water bodies are predators. They attack small benthic animals and use a special proboscis to suck out their contents.

The nutrition of flatworms and roundworms is somewhat different, since the latter have a through-type digestive system. It has the form of a tube with oral and anal apertures, therefore the metabolism at them occurs more intensively. Free-living terrestrial flatworms feed on larvae of insects living in moist forest litter.

Ciliated worms

Representatives of this class of animals live in water. In this environment, epithelial cells secrete a special secret that helps to keep small benthic animals - crustaceans, hydras, various larvae. The food of flat worms of this class is very unusual.

For example, in milky white planaria, the oral opening is located in the middle of the body on its ventral side. The worm creeps on the victim, thus holding it. Further, through the mouth a proboscis protrudes, by means of which the planaria drains the liquid contents from the body of the prey.

Flukes

What do the flatworms eat that are parasites? Let us consider this question on the example of the trematode class. Their name is due to the presence of suckers. Usually there are two: oral and abdominal. With their help, parasites attach themselves to the internal organs of the host's body.

These worms undergo a rather complex life cycle during their development. For example, eggs of the liver flukes first, along with undigested remnants of cattle feed, enter the water, and thence into the body of mollusks, where tailed larvae develop from them, which again go into the water. Settling on plants, they turn into cysts. Cattle, which is the final owner of the parasite, become infected when drinking water or eating grass. In his body, the cyst begins to grow and develop into an adult specimen, whose size reaches 3 cm.

It is at this stage that the food of the worm takes place. At the bottom of the first sucker is a mouth opening opening into the intestine. The digestive system looks like a bag or two channels that blindly end. Since these helminths lack a body cavity and circulatory system, the gastrointestinal tract also performs the function of supplying the whole organism with various substances. Flukes feed on blood, mucus and epithelial cells. The products of helminth exchange are released through the mouth opening, while poisoning the organism of the final host.

Tape worms

Representatives of this class are characterized by a complete absence of the digestive system. This feature is related to their lifestyle. There are special attachment organs on the head of tapeworms. They can be suckers, hooks or proboscis. With their help, parasites attach to the walls of the small intestine. Partially digested substances they absorb the entire surface of the body, so they do not need the digestive system.

Tape worms pose a serious danger to a person who is for them both an intermediate and final master. Absorbing a large number of nutrients and vitamins, the parasite grows rapidly, sometimes reaching a gigantic size. For example, bull and pork chain grow to 10 meters. By feeding on substances intended for humans, parasites quickly deplete the body. Moreover, the host is poisoned with the products of the exchange of worms. A person infected with helminths experiences weakness, dizziness, nausea, lack of appetite, and even loss of consciousness.

So, what feeds flat worms depends on their habitat and mode of life. These conditions also determine the peculiarities of the structure of their digestive system. This type of animal combines 3 classes: cilia, tapeworms and flukes. The first are free-living predators, which hunt in reservoirs for smaller animals. Flukes are parasites that attach to internal organs and feed on foods and tissues. Tape worms are devoid of digestive system. These parasites live in the lumen of the small intestine of animals and humans, feeding on already digested food particles.