Self-disintegration.

When particularly unfavorable conditions occur, for example, in the case of a strong “increase in water temperature or as a result of lack of oxygen, etc., many planarians are capable of disintegrating into pieces, which, when favorable conditions occur, are restored into whole planarians. This phenomenon is known as autotomy or self-mutilation.Many forms are divided into parts under normal conditions during the annual life cycle, and this phenomenon can be considered a form of asexual reproduction.

The tenants feed the landlord.

When the sea begins to ebb off the coast of Brittany, green spots appear on the exposed bottom, which gradually become darker and at the same time change their shape. These spots are formed by accumulations of countless small eyelash worms belonging to the genus convolutes. The green coloration of these animals depends on the green algae that live in the tissues of the worm itself; These are the so-called zoochlorella, which belong to the flagellated protozoa. The species in question here is called Convolute roscoffensis, which, like all worms of this order, lacks an intestine. In their youth, individuals of this species are still able to capture food and processes of intracellular digestion occur. Numerous observations indicate that adult worms are incapable of independent nutrition until zoochlorella appear in their internal tissues and begin to multiply vigorously. These zoochlorella are so adapted to symbiotic way of life, which are no longer capable of independent existence. We can say that they have completely and completely “become part of the tissues" of their owner. In connection with this peculiarity of their internal organization, convolutes often sit motionless in place for the whole day and, moreover, in such a way that perhaps the largest part of their body is exposed to light. By being exposed, if possible, to the most abundant exposure to sunlight, the convolute “creates” the most favorable conditions for the existence of zoochlorella living inside its body.

Immortals under the operator's knife.

“Immortals under the operator’s knife” is what one scientist called the planarian. The regenerative ability is especially well expressed in planarians lugubris and gonocephalus. Small fragments measuring 1/100 of the planarian body, and according to some data 1/280 of its part, form anew the whole organism. By repeated regeneration it is possible to obtain planarians not exceeding 1/500 cm.

A paradoxical animal.

At first, scientists were perplexed, what kind of cruciform animal is this? 2 heads, 2 tails... Then they established that these are 2 worms fused with each other, and they gave the animal the name “paradoxical worm”. The adhesions are obtained in such a way that one partner covers the dorsal papilla of the other partner with his sucker, while the latter behaves in exactly the same way in relation to the first.

The body of such worms has a thread-like, spindle-shaped, sometimes sausage-shaped shape. They have a primary body cavity, an intestine with an anus, and there is one more feature - they are heterosexual. The primary body cavity contains all the organs and systems necessary for the existence of this worm. This part of the body is filled with fluid, which gives it elasticity and ensures good metabolism between all organs. They do not have a circulatory or respiratory system.

If we talk about the digestive tract, then we need to mention that it consists of three parts, namely the mouth, in which there is a certain row of teeth, then the esophagus, and the third part is the anus.

Since it was already said earlier that roundworms are heterosexual, let’s talk about the structure of their genital organs. In the female they are paired, and in the male they are unpaired and have the shape of a tube. The male has a vas deferens, testis and ejaculatory duct, and the female has ovaries, oviducts and a uterus - all connected to the vagina. Worms reproduce only sexually, no other way.

What roundworms can a person have?

If the number of roundworms is large enough, then intestinal blockage, bile duct obstruction, and appendicitis may well occur. In this case, medical intervention is needed, otherwise the result can be very disastrous. Also, human roundworm can affect not only the abdominal cavity, but also the ears, throat and heart, but this is much less common.

In everyday language, the term "worm" is applied to various living forms, such as larvae, insects, millipedes, centipedes, and even some vertebrates. All types of worms are divided into several groups:

1. Flatworms

Family planarians lives in fresh water. They are hermaphrodites (have male and female reproductive organs). They have a simple brain (ganglia) and nervous system, a arrow-shaped head and two eyespots. They have the ability to regenerate.

Trematodes or flukes have complex life cycles, and they live within one or more hosts. These worm species are characterized by a well-developed digestive system with a mouth at the front end and one or more suckers surrounding the mouth. The suckers are used to remain attached to the inner surface of the host's body.

2. Tapeworms

Tapeworms come in all shapes and sizes. Whether they're on a rain-soaked sidewalk, in a dumpster, or on the end of a fishhook, the worms most people know are of the segmented variety.

Nematoda have successfully adapted to almost every ecosystem from marine (salt water) to fresh water, to soils, from polar regions to the tropics, and from the highest to the lowest altitudes. These worms are ubiquitous in freshwater, marine and terrestrial environments, where they often outnumber other animals and are found in places as diverse as mountains, deserts and ocean trenches.

4. Annelids

Annelids(Nereis, sea mouse, sandworm, earthworm, tubifex, leeches).
Annelids (Annelida, from Latin anellus, "small ring"), also known as annelids or segmented worms, are a large phylum with more than 17,000 extant species, including earthworms and leeches. Species of these worms are adapted to different ecologies—some live in marine environments such as intertidal zones and hydrothermal vents, others in fresh water as well as moist terrestrial habitats.

Earthworms

Any person inclined to work on the earth has repeatedly encountered these shiny, pinkish-brown tubular life forms that hastily disappeared into the comforting damp darkness of the soil. These are known to everyone earthworms. Let us note a few of their features:

1. Earthworms are incredibly diverse, with approximately 6,000 species worldwide. Some of the most familiar species to see in your garden are the night crawler (which can be seen after dark), the angle worm (a popular fishing bait) or the earthworm.
2. Of the 180 species of earthworms found in the United States and Canada, 60 are invasive species brought from the Old World.
3. Lacking lungs or other specialized respiratory organs, earthworms breathe through their skin.
4. The skin emits a lubricating fluid that facilitates movement through underground burrows and helps keep the skin moist.
5. Each earthworm is both male and female, producing both eggs and sperm. One end of their body is more sensitive to light than the other.
6. Earthworms are attracted to each other by smell. These types of worms mate on the surface of the earth.
7. Earthworm eggs look like tiny lemons. Newborn worms emerge from the eggs very small but fully formed. They produce reproductive organs during the first 2-3 months of life and reach full size after about a year. They can live up to eight years.
8. The size of these worms varies depending on the species, from less than 2 cm to almost 3 m. Such large monsters are not found in gardens. You have to go to the tropics to see them.
9. In the northern states of Canada, after the last ice age, earthworms were destroyed. Therefore, modern worms found in glaciated areas are invaders from the ocean that were deliberately introduced by early settlers under the assumption that the worms would improve the soil.
10. The earthworm's digestive system is a tube that runs straight from the front end of the body to the back, where the digested material passes out. Since they primarily eat fallen leaves and soil, this allows the worms to move nutrients such as potassium and nitrogen into the soil. In addition, the movements of the worm in the ground create holes that facilitate the passage of air and loosen the soil.
11. The northern forest of the United States suffers from earthworms that quickly eat the leaf layer (duff), causing nutrients to become less available to young growing plants and the soil becoming more compact instead of loosening, which negatively affects the development of these forests. Earthworms can also speed up the passage of water through forest soil, which may be beneficial in a farmland or garden with compacted soil, but not in such forests.
12. Because earthworms spend most of their lives underground, plowing the soil and creating complex networks of burrows (which can extend 2 m or more), their bodies are basically like a tube with muscles arranged in two layers. One set of fibers runs lengthwise and the other runs widthwise, like a corset around his body. Tightening the corset forces the worm's head to move forward. The wave of contractions then travels back through the body, squeezing the worm forward until the long muscles grip the tail.
13. Thin-skinned earthworms have no resistance to the sun's ultraviolet radiation, so daylight can be fatal, and they are usually only found on the surface in dull, wet weather.
14. If a worm loses one end of its body, it can be replaced, however, if it is cut in half, it dies. Contrary to popular belief, they do not become two new worms.
15. Fossil worms similar to earthworms have been found in rocks laid down 600 million years ago.

The earthworm is such a familiar creature and few people think about its enormous importance in nature. The contribution of earthworms in relation to soil fertility is enormous. They burrow through the ground, dragging leaves and other plant debris into the soil, allowing organic matter and air to penetrate and water to infiltrate. Their activity over millions of years is vital to the creation of rich, fertile soils from dense, barren clays. Unfortunately, the earthworm has many enemies - almost all animals and birds, but moths are the biggest threat, since one moth can eat up to 50 earthworms in one day.

• Kingdom: Animalia, Zoobiota = Animals (Invertebrates)

Cryptozoologists are well aware of the Olgoi-Khorkhoi, a killer worm whose existence has not yet been proven. Translated from Mongolian, this strange name means “intestinal worm.” His body is supposedly long and red - like released intestines. The head and tail are indistinguishable, and the tail itself grows up to a meter in length.

Olgoy-Khorkhoi lives in isolated areas of Mongolia, preferring the hot sands of the Gobi. It comes to the surface only in the hottest months of the year, the rest of the time it hibernates. It moves in convulsive twists, and when it encounters a living creature, it quickly curls up into a ring, changes color and kills the victim from a distance (with poison, or, according to another version, with electricity).

The Mongols talk about this worm with the same conviction as the Tibetans talk about the yeti. Western researchers have been interested in this desert invertebrate since the beginning of the 20th century, but it has not yet been caught or even photographed. In our country, Olgoy-Khorkhoi is known thanks to the story of the same name by Ivan Efremov (1943), who was fascinated by such mysteries and described a meeting of a group of Soviet surveyors with an “intestinal worm” in the Dzungarian Gobi.

Considering that the Gobi fauna contains many endemic, that is, characteristic only of this region, species of animals, it can be assumed that behind the “mask” of the Olga-Khorkhoi there is a poisonous reptile unknown to science, or, less likely, we are really talking about a large annelid worm, adapted to desert conditions.

On the other side of the world, in South America, lives a distant relative of the Mongolian worm - minochao (derived from the Portuguese "earthworm"). Reports of it appeared in the 19th century. A giant monster ruled in Brazil and Uruguay, dragging cattle underground. The Aborigines described it as a “huge, house-sized” beast with two horns. Minochao dug up the ground into tunnels, and as he moved, he uprooted old pine trees. At the beginning of the 20th century, evidence of a meeting with him dried up. Researchers suggest that the role of the “earthworm” was played by an ordinary anaconda.

In 2004, British actor Paul Hurley held an artistic event called “Turning into an Animal.” He decided to find out what it was like to be an earthworm. To do this, Paul wrapped himself in cellophane and crawled around the plots of land for more than a week. The farmers' reaction to this event is unknown.

Caenorhabditis elegans worms survived the Columbia space shuttle disaster. The boxes in which they were delivered into orbit experienced extreme heating and an overload of 2500 g, but their inhabitants survived. This fact is considered the most convincing evidence of the “meteorite” origin of life on Earth.

Charles Darwin loved to fish in his youth, but before hooking worms (which he considered to be perhaps the most important creatures that give flora and fauna to the Earth) he always killed them with sea water. In 2005, Norwegian scientists proved that worms placed on a hook do not feel pain or discomfort.

The Chinese character for earthworm literally translates to "earth angel."

A few months ago, the pha-4 gene was discovered in nematode worms, which slows down the aging of the body. Worms could be the key to human immortality.

Nemertean marine worms Lineus longissimus are considered to be the longest creatures that have ever lived. In 1864, a 55-meter-long specimen washed ashore in Scotland. The African earthworm (Microchaetus rappi) can grow to almost 7 meters and weigh 1.5 kg.

The New Zealand worm Spenceriella gigantea cannot boast of cyclopean sizes (maximum 1.5 meters in length), but it glows in the dark. With just one worm you can read a book at night.

The meter-long North American palus worm (Driloleirus americanus) has a pale pink color, smells like lilies and is capable of burrowing into the ground to a depth of 5 meters. Until recently it was considered extinct.