Tardigrades are the Earth's super extreme creatures. Water bear. Type of microscopic invertebrates

exists in nature unique creation, nicknamed "water bear". Little known (with the exception of zoologists and space specialists), knowledgeable people it amazes with its appearance, and its survivability. The creature received its primary name for its clear resemblance to a candy or teddy bear. True, he has six legs, and it’s difficult to call his “face” cute, but the rest is clearly visible. And the “water” bear is because it is an inhabitant of this environment and cannot live without moisture (in the literal sense of the word).

History of discovery

There is reason to believe that tardigrade water bears were exactly the creatures that the creator of the microscope, van Leeuwenhoek, saw back in 1702. However, the first official discovery of these unique specimens was in 1773, when they were described by the German pastor Götze. Taken aback by their appearance, he gave them the name kleiner wasserbär, which translates from German as water bear. Microscopic creatures were studied and described in more detail by the Italian biologist Lazzaro Spallanzani, and this happened in 1776. Due to the extremely slow mobility of animals, he called them il tardigrado, as a result of which the official scientific name became the term Tardigrada, that is, tardigrade.

Structure of a water bear

The first thing worth noting when studying a tardigrade is the size of the animal. There are about 960 species of sea bears, and their body size varies from 0.1 to one and a half millimeters. It is very difficult to examine even the largest individual without a microscope. Tardigrades belong to the class of invertebrates; they have a glassy, ​​translucent body, visually divided into 4 segments by constrictions. Due to the presence of a chitinous shell and periodic molting, the water bear is sometimes compared to insects. Most species have four pairs of limbs, but one of the smallest “breeds,” just a tenth of a millimeter long, is an exception: the hexapod tardigrade. Each paw ends in 4-6 claws. The last pair of legs is oriented backwards.

The “face” of the creature is very unusual and resembles a dust collector on a vacuum cleaner. The mouth is equipped with a kind of stilettos, with which the water bear pierces the food shell. These animals have nervous, digestive, reproductive and nervous system, however, the circulatory and respiratory systems are absent. Instead of blood, the entire body cavity is occupied by a special liquid, and tardigrades breathe through the skin. They have additional ones in the form of a pair of appendages, and, oddly enough, eyes, which are pigment spots on the front of the body, but not in the place that can be conventionally called the head.

The water bear has a color that depends on its habitat conditions. The shade can be in the color range orange - scarlet or olive - dark green.

Tardigrades are heterogeneous, but males are much more rare than females, so multiple cases of parthenogenesis (reproduction in the absence of fertilization) have been recorded.

Tardigrades are distributed throughout the world from the tropics to the Arctic Circle. However, if they can choose, they prefer moist lichens and mosses. Distribution in water bears is passive: individuals move due to currents of water or wind, and are also carried on the feathers of birds and the fur of animals.

Nutritional Features

Unkillable creature

Most of all, the water bear interested scientists for its vitality. These creatures are able to maintain their life and ability to reproduce in a wide range of temperatures - from (-273 degrees) to unbearable heat of +150. They survive in aggressive environments, such as hydrogen sulfide atmospheres. Radiation is also not an insurmountable barrier to survival for them: after exposure to a dose of 570 thousand roentgens, half of the water bears remained alive. For reference: radiation of “only” 500 roentgens is lethal for humans. Moreover, the surviving tardigrades could still give (and did) offspring.

Space sustainability

Most of all, the scientific community was interested in the Tardigrada's ability to withstand the conditions of space. In 2008 research group led by Swedish ecologist Ingmar Jonsson, sent an experimental batch of tardigrades into orbit around the Earth. One group was placed in a vacuum, the second was simultaneously irradiated with radiation, and two were subjected to intense ultraviolet treatment. Subjects in outer space They stayed for 10 days and almost all of them were dried out. However, upon returning to more favorable conditions, most of the microscopic creatures returned to life, retaining the ability to reproduce.

Basics of Survival

The ability by which a water bear can endure such wide range unfavorable conditions- the ability to fall into suspended animation through controlled anhydrobiosis. In other words, the tardigrade dries itself out, leaving a negligible amount of water in its body. In order not to lose them, the tardigrade forms a kind of waxy shell on the surface of the body. When dried, the tardigrade activates additional protective functions: sugar molecules prevent cell expansion, and the production of antioxidants is triggered, which resist radiation and prevent DNA destruction. When water enters the environment, the body of the tardigrade begins to absorb it, and all vital functions are restored.

Natural enemies of the water bear

Despite all its vitality, the water bear is by no means immortal. Successfully counteracting adverse external factor, he is quite helpless against predators who are not averse to feeding on him. In addition to their own relatives, tardigrades are attacked by rotifers, mites, springtails, round and larvae of various insects and crayfish. Some of the tardigrades die, becoming prey; their hyphae intertwine into loops, in which the water bear gets stuck, as if in a trap, after which the mushroom threads grow into it. In addition, there are fungi whose spores are attractive to tardigrades for food. However, once in the intestines of a water bear, the spores germinate, using the animal as a growing medium.

Water bears are colloquial name tiny multicellular creatures that have always fascinated microscopists. Scientifically they are called tardigrades, and with four pairs of squat legs and a slow, awkward gait, they really do look like microscopic bears (eight-legged microscopic bears, to be more precise). Tardigrades live more widely than humans, so almost any handful of water can contain several of them. However, the easiest way to find and care for them is to look into pieces of damp moss.

Steps

Search for Tardigrades

Learn more about tardigrades. Despite their size, these creatures are extremely interesting to watch! Tardigrades, or water bears, are one of the most amazing animals on Earth, and they live among moss and ferns. Tardigrades are able to survive:

• Low temperatures down to -200°C and high temperatures no higher than 151°C
• Freezing in a block of ice
• Lack of oxygen for days, possibly even months
• Water shortages for decades
• X-ray radiation level 1000 times higher than the lethal dose for humans
• Most harmful chemicals
• Boiling alcohol
• Low pressure in a vacuum (like in outer space)
• Extreme pressure, six times greater than the deepest part of the ocean

1. Tardigrades live in humid environments. Most tardigrades live in water, but the easiest places to find them are in damp moss, lichen or fallen leaves. Look in the woods, near ponds, and even in your backyard. Pay special attention to damp areas where tardigrades are most active. If you can't find anything like this, take a sample of dry habitat, as it may contain tardigrades in a state of extreme hibernation (cryptobiosis), waiting for water to bring them back to life.

   Using tweezers, take a sample of the moss or lichen. Place the sample in paper bag or an envelope to dry it a little. Plastic bag will prevent water from escaping and thus lead to the growth of mold, which will block the animals from your view.

   • Take samples of several types of moss, lichen or leaf litter to see which habitats are most popular with tardigrades.
   • Tardigrades are more likely to live in soft lichen than in hard, hard lichen. Water bears can even be found in powdery mildew that covers rocks and brick walls.

2. Soak the moss or lichen completely. Fill the Petri dish with water, preferably distilled or rainwater, to a height of about one centimeter. Leave the plant to soak for anywhere from 8 to 24 hours to awaken the water bears.

   Squeeze the water from the moss into another petri dish. Squeezing or shaking the residence will transfer these microscopic creatures into the water.

   Find a microscope with low magnification. Most tardigrades are between a quarter and half a millimeter in length. It's almost within human vision, somewhere a little smaller than a point. To see them you will need a microscope with approximately 15x or 30x magnification. If you don't have one, look for a cheap stereo microscope on the Internet.

3. Find tardigrades. Place a microscope over a Petri dish and look through it at the moss. Sometimes it is easier to notice them if you shine a powerful flashlight through the side wall of a Petri dish. This will highlight tardigrades and other creatures in white. Look for an animal with four pairs of short legs that swings them slowly to move its misshapen body. The last pair of legs faces backward and is very easy to mistake for a tail or the edge of the body.

   • If there's a water bear there, you're in luck. Pour the water back onto the moss that will become its home.
   • Otherwise, replace the water and try again on another piece of moss until your search is successful.

If the Earth suddenly suffers from natural disaster, will survive the fall of an asteroid or the destruction of the ozone layer, only tardigrade. Most people don’t know who it is (or even what it is), since its economic significance is zero. Although this is a very interesting organism.

Tardigrade: the toughest creature on the planet

This microscopic invertebrate is the hardiest and most resilient of all known animals . It can survive in such extreme conditions:

1. Temperature from -20 °C (up to 30 years) to 151 °C (several minutes). The microorganism can survive for several days at -200°C and for several minutes at -272°C;
2. Some species can withstand pressures up to 1,200 times atmospheric pressure. Even the depths Mariana Trench they won't care;
3. Radiation resistance 1000 times higher than any other biological species. Lethal absorbed dose ionizing radiation is 5000 gray. This happens due to the specific structure of the body, which is able to quickly restore damage to DNA after a destructive effect;
4. The fact of survival in outer space for 10 days in a row has been scientifically proven. Russian scientists came to this conclusion during the Photon-3 mission in September 2007. Despite the fact that only 68% of the specimens remained alive, many of them managed to produce viable embryos.

Anatomy and morphology of the creature

Let's consider external and internal features"water bear":

• Body size ranges from 0.3 to 0.5 mm, although "giant" varieties are known up to 1.2 mm in length;
• The body is barrel-shaped and is conventionally divided into five parts: the head, three body segments (three pairs of legs each) and the caudal segment (where the fourth pair of legs is located);
• The legs are without joints, but have claws (from four to eight each);
• There are no respiratory organs, gas exchange occurs throughout the entire volume of the body;
• The pharynx passes into a small esophagus, which goes into the intestines, which occupies most bodies. It is the main site of food digestion. Shedding usually occurs during shedding;
• The mouth is equipped with sharp teeth for piercing plants, algae and small invertebrates. They are lost during molting, then new ones grow;
• Upon reaching maturity, the number of somatic cells in all individuals is compared;
• The brain consists of several lobes that create a bilaterally symmetrical pattern. It is attached to the large ganglion just below the esophagus. From it emanate branches of the ventral nerve chain along the entire length of the body.
• Some species have sensory processes on the surface of the body, which allow them to better navigate in space.

Where does the tardigrade live?

The range of this microanimal is truly limitless, which makes it possible to call it a cosmopolitan. It can be detected anywhere on the planet Earth: from mountain peaks to depths of the sea and mud volcanoes, from tropical forests to Antarctica.

Urban habitats have been little studied.

Lifestyle and reproduction

There is a division into male and female individuals, although some species have the ability to reproduce without the participation of the opposite sex (parthenogenesis).

Embryonic development does not occur in the female's womb: it begins after the eggs are laid. After no less than 14 days, a new organism is born.

Juveniles have the same number of cells as adults. Growth occurs due to an increase in the size of individual cells (hypertrophy), and not due to division.

The diet looks like this:

• The smallest plant organisms;
• Bacteria;
• Fungal spores;
• Protozoa;
• Sometimes cannibalism is practiced: the larger ones devour the small and weak ones.

In most cases, these creatures exhibit a strict vegetarian diet and primarily eat algae cells.

List natural enemies small: mites, insect larvae, earthworms And carnivorous mushrooms. The latter are a particularly dangerous enemy: they throw out a cellular thread and trap the unfortunate victim.

Is it possible to kill a tardigrade?

The key condition for its survival is presence of a thin film of water. This leads to the Achilles heel of the hardiest microorganism on Earth:

• Research shows that the maximum period of dehydration is about 10 years. The organism falls into a state of cryptobiosis and emerges from it if living conditions improve;
• However, the creature cannot remain in this state forever. It is for this reason that it cannot be found in deserts and other arid locations on Earth;
• This leads to a logical conclusion: the right way kill a tardigrade - dry out its habitat and maintain such conditions for decades .

A number of laboratory experiments have shown the lethal effects of some environmental toxins, especially sulfur trioxide. Therefore, these animals can be used as a biological indicator of the condition environment. Death also causes contamination of mosses with heavy metals (proven by Hungarian scientists).

This animal is a clear demonstration of the worldly wisdom “if you drive more quietly, you will go further.” While other representatives of the biosphere are bending over backwards for the sake of reproduction and survival, this unpretentious organism silently contemplates this meaningless fuss. This creature's name is Tardigrade. Who she is has been known for almost 250 years, but people never cease to be amazed at her outstanding abilities to endure any hardships and hardships, to survive in almost any environment.

Video about the life and death of a tardigrade in its natural environment

In this video, biologist Arkady Matrosov will tell you about a creature that cannot be killed, capable of surviving any environmental disaster:

They can survive up to ten years without water, can survive at -271°C in liquid helium and at +100°C in boiling water, can withstand 1000 times more radiation than humans, and have even been in outer space!

Tardigrada (lat. Tardigrada) is a type of microscopic invertebrates close to arthropods. This animal was first described in 1773 by the German pastor I. A. Götze as a kleiner Wasserbär (small water bear). In 1777, the Italian scientist Lazzaro Spallanzani gave them the name il tardigrado, the tardigrada, the Latinized form of which is Tardigrada (from 1840).

The body of tardigrades (or they are also called water bears) has a size of 0.1-1.5 mm, translucent, consisting of four segments and a head. Equipped with 4 pairs of short and thick legs with 4-8 long bristle-like claws at the end, with the last pair of legs directed backwards. Tardigrades move really very slowly - at a speed of only 2-3 mm per minute. The mouthparts are a pair of sharp stylets that serve to pierce the cell membranes of algae and mosses on which tardigrades feed. Tardigrades have digestive, excretory, nervous and reproductive systems; however, they lack respiratory and circulatory system- breathing is cutaneous, and the role of blood is played by the fluid filling the body cavity.

Currently, more than 900 species of tardigrades are known (in Russia - 120 species). Due to their microscopic size and ability to withstand adverse conditions, they are distributed everywhere, from the Himalayas (up to 6000 m) to the depths of the sea (below 4000 m). Tardigrades have been found in hot springs, under ice (for example, on Spitsbergen) and on the ocean floor. They spread passively - by wind, water, and various animals.

All tardigrades are aquatic to some extent. Approximately 10% - Marine life, others are found in freshwater bodies, but most inhabit moss and lichen cushions on the ground, trees, rocks and stone walls. The number of tardigrades in moss can be very large - hundreds, even thousands of individuals in 1 g of dried moss. Tardigrades feed on the fluids of the plants and algae on which they live. Some species eat small animals - rotifers, nematodes, and other tardigrades. In turn, they serve as prey for ticks and springtails.

Tardigrades attracted the attention of early researchers with their amazing endurance. When unfavorable conditions occur, they are capable of falling into a state of suspended animation for years; and when favorable conditions arise, they come to life quite quickly. Tardigrades survive mainly due to the so-called. anhydrobiosis, drying.

When dry, they draw the limbs into the body, decrease in volume and take the shape of a barrel. The surface is covered with a wax coating that prevents evaporation. During suspended animation, their metabolism drops to 0.01%, and the water content can reach up to 1% of normal.

In a state of suspended animation, tardigrades endure incredible loads.

* Temperature. Stay for 20 months. in liquid air at -193°C, eight-hour cooling with liquid helium to -271°C; heating to 60-65°C for 10 hours and up to 100°C for an hour.

* Ionizing radiation of 570,000 roentgens kills approximately 50% of tardigrades exposed. For humans, the lethal dose of radiation is only 500 roentgens.

* Atmosphere: Came to life after being in a vacuum for half an hour. They can remain in an atmosphere of hydrogen sulfide and carbon dioxide for quite a long time.

* Pressure: During an experiment by Japanese biophysicists, “sleeping” tardigrades were placed in a sealed Plastic container and immersed him in a chamber filled with water high pressure, gradually bringing it to 600 MPa (approx. 6000 atmospheres), which is almost 6 times higher than the pressure level at the lowest point of the Mariana Trench. It did not matter what liquid the container was filled with: water or a non-toxic weak solvent, perfluorocarbon C8F18, the survival results were the same.

* Humidity: there is a known case when moss taken from the desert, approximately 120 years after it was dried out, was placed in water, the tardigrades in it came to life and were capable of reproducing.

In September 2007, the European Space Agency sent several individuals into space, to an altitude of 160 miles. Some water bears were exposed only to vacuum, some were also exposed to radiation 1000 times higher than background Earth radiation. All tardigrades not only survived, but also laid eggs and successfully reproduced

Experiments in orbit have shown that tardigrades - tiny arthropods ranging in size from 0.1 to 1.5 millimeters - are able to survive in outer space. In their work, the results of which were published in the journal Current Biology, biologists from several countries showed that some tardigrades are able to fully restore their vital functions and produce viable offspring.

In this work, a group of biologists, led by Ingemar Jonsson from the University of Kristianstad, sent two species of tardigrades into Earth orbit - Richtersius coronifer and Milnesium tardigradum. The arthropods spent 10 days on board the Russian unmanned vehicle Foton-M3. A total of 120 tardigrades have been in space, 60 individuals of each species. During the flight, one group of arthropods, including both species, was in a vacuum (the shutter separating the chamber with tardigrades from open space was open), but was protected from solar radiation special screen. Two more groups of tardigrades spent 10 days in a vacuum and were exposed to ultraviolet A (wavelength 400 - 315 nanometers) or ultraviolet B (wavelength 315 - 280 nanometers). The last group of arthropods experienced all the “features” outer space.

All tardigrades were in a state of suspended animation. After 10 days spent in outer space, almost all organisms were dried out, but on board the spacecraft the tardigrades returned to normal. Most animals exposed to ultraviolet radiation with a wavelength of 280 - 400 nm survived and were able to reproduce. R. coronifer individuals were unable to survive the full range of exposures ( low temperature, vacuum, ultraviolet A and B), only 12% of animals in this group survived, all of them belonged to the species Milnesium tardigradum. However, the survivors were able to produce normal offspring, although their fertility was lower than that of the control group on Earth.

So far, scientists do not know the mechanisms that helped tardigrades survive exposure to the harsh ultraviolet radiation of outer space. Radiation of this wavelength causes DNA breaks and mutations. Tardigrades probably have special defense systems that protect or quickly repair their genetic material. Understanding how living systems are able to protect themselves from the harmful effects of space is important for the development of astronautics and the organization of long-distance space flights and a lunar base.

What is the secret of such survivability of tardigrades? They are not only able to reach a state where their metabolism practically stops, but also maintain this state for years at any time during their existence.

Here is an example of the Arctic Adorybiotus coronifer in this frozen state:

And here seasonal changes this creature depending on weather conditions (1 – cold autumn and winter; 2 – spring; 3 – active form, summer; 4 - molting):

Thus, the existence of tardigrades refutes the theory that only cockroaches are able to survive nuclear explosion. This creature is much more tenacious, many times smaller than a cockroach, and also much cuter :)

Their Italian name "tardigrado" is of Latin origin and means "slow moving". It was given at the discovery of animals due to their slow movement. Tardigrades are almost transparent and on average reach half a millimeter in length. The body of the tardigrade consists of five parts: a clearly defined head with a mouth and four segments, each of which has a pair of legs with claws. The body of animals is covered with a thin and flexible, resistant cuticle, which they shed as they grow (molting). Anatomical structure these small animals resemble the structure of larger ones. In particular, tardigrades have a brain on the dorsal side, small eyes and nerve ganglia on the ventral side (like flies). Their digestive system includes a mouth with sharp stylets and a sucking expansion of the pharynx to suck out the contents of the cells of other microscopic animals or plants, intestines and anus. Fortunately, tardigrades are not pathogenic to humans. They have longitudinal muscles and excretory organs.

A single sac-shaped gonad located dorsally distinguishes males, females and self-fertilizing hermaphrodites. Some species consist only of females, reproducing by parthenogenesis, that is, without the participation of males. Due to their small size, tardigrades do not require the respiratory and circulatory systems for gas exchange. The fluid present in the body cavity performs the functions of the respiratory and circulatory systems. Systematically, tardigrades are very close to arthropods, in particular to crustaceans and insects, which also lose their cuticle during growth and count greatest number species on Earth. Being very close to arthropods, tardigrades are not them. Various species of tardigrades have been found everywhere on the planet: from the polar regions to the equator, from coastal zones1 to the deep ocean, and even on mountain tops. To date, approximately 1,100 species of tardigrades have been described that live in seas, lakes and rivers or in terrestrial environment a habitat. Their numbers are increasing rapidly every year due to new discoveries and revisions of existing species.

Although all tardigrades require water to survive, many species can survive even in the temporary absence of water. Thus, the greatest number of tardigrades were found on the ground, where they live in mosses, lichens, leaves and moist soil. The widespread distribution of tardigrades on Earth is closely related to their survival strategies.

Terrestrial tardigrades can live in two main states: active state and cryptobiosis2. When active, tardigrades require water to eat, grow, reproduce, move, and carry out normal activities. In a state of cryptobiosis, metabolic activity stops due to lack of water. When environmental conditions change and water appears, they can return to an active state again. Such a reversible suspension of metabolic activity was naturally compared to death and resurrection. Terrestrial tardigrades respond to stimuli differently depending on the sources of stress, and their responses are collectively termed cryptobiosis. This condition can be caused by drying (anhydrobiosis), freezing (cryobiosis), lack of oxygen (anoxybiosis) and high concentration dissolved substances (osmobiosis).

Anhydrobiosis, a state of metabolic rest due to almost complete desiccation, is a common phenomenon in terrestrial tardigrades, which can enter this state several times. To survive in this transitional state, tardigrades must dry out very slowly. The grass, mosses and lichens inhabited by terrestrial tardigrades contain numerous pools of water, like sponges, which dry out extremely slowly. Tardigrades dry out as their environment loses water. They have no other way to escape, since tardigrades are too small to run. The tardigrade loses up to 97% of its water content and dries out to form a shape approximately one-third its original size, called a "barrel". The formation of such a “barrel” occurs as the animal draws its legs and head into its body to reduce its area. When rehydrated by dew, rain or melted snow, the tardigrade can return to an active state within minutes or hours. This amazing ability to survive appears to be a direct response to rapid and unpredictable changes in the terrestrial microenvironment.

Marine tardigrades do not develop such features because their environment is usually more stable. An animal can be in a state of anhydrobiosis from several months to twenty years, depending on the species, and survive almost anything. The most famous feature of the tardigrade is its ability to survive in extremely extreme conditions. During the experiments, dehydrated tardigrades were exposed to temperatures ranging from minus 272.95°C, i.e. close to absolute zero, up to +150°C, i.e. temperature in the oven when baking the cake. After rehydration, the animals return to an active state. Thus, tardigrades that were in a state of anhydrobiosis for several years at a temperature of -80°C survived. Tardigrades have also been exposed atmospheric pressure, 12,000 times greater normal pressure, as well as exposure to excessive amounts of asphyxiating gases (carbon monoxide, carbon dioxide), and they were able to return to an active state after rehydration. Exposure to ionizing radiation more than 1,000 times lethal to humans had no effect on the tardigrades.

In 2007, the tardigrade became the first animal to survive the effects of the destructive space environment. In an experiment carried out on the TARDIS spacecraft, thanks to equipment provided by the European Space Agency, tardigrades in a state of anhydrobiosis were directly exposed to solar radiation and the vacuum of space during the mission of the Russian spacecraft Foton-M3. While the vehicle was in orbit 260 km above the Earth's surface, scientists opened a container containing barrel tardigrades, thereby exposing them to the sun and, in particular, ultraviolet radiation. Upon returning to Earth after rehydration, the animals began to move - they survived.

In the summer of 2011, during the TARDIKISS experiment, supported by the Italian Space Agency, tardigrades were sent into space on the International space station​(ISS) on NASA's space shuttle Endeavor. Tardigrades and their eggs were exposed to ionizing radiation and microgravity. Once again, after the animals returned to Earth, the eggs hatched and the animals survived, eating, growing, molting, and reproducing as if they had returned from a nice little cruise through space. What biological resistance mechanisms do tardigrades use to protect themselves under these different stress conditions?

The physiological and biochemical mechanisms of tardigrades that ensure tardigrade endurance are still little known, and to date there is no generally accepted explanation. However, in the last few years, the endurance of tardigrades has attracted interest. a large number of scientists who used new molecular and biochemical tools in their research. It is now clear that the mechanisms underlying anhydrobiosis may contribute to the endurance of tardigrades under other stressful conditions, using different biochemical and physiological mechanisms. The underlying mechanism involves the synthesis of various molecules that act together as bioprotectants: trehalose, sugar, and stress proteins commonly called “heat shock proteins.”

When dehydrated, loss significant amount water, as a rule, leads to the destruction of cells and tissues and, consequently, the death of the organism. In the case of tardigrades, there is a relationship between the acquisition of resistance to dehydration and the biosynthesis of trehalose as tardigrades accumulate this sugar during dehydration. The synthesis and accumulation of trehalose protects tardigrade cells and tissues by replacing water lost through dehydration. Heat shock proteins, particularly HSP70, appear to act in concert with trehalose to protect large molecules and cell membranes from damage caused by dehydration. Ionizing and ultraviolet radiation destroy large molecules such as DNA and lead to oxidative stress, causing effects similar to accelerated aging.

It is for this reason that the ability of tardigrades to survive intense radiation leads scientists to believe that animals have an effective DNA repair mechanism and a protective antioxidant system. The growing interest of scientists in tardigrades is undoubtedly associated with the possibility of applying the acquired knowledge about dehydration and the mechanisms of frost resistance of tardigrades to the cryopreservation of biomaterials (for example, cells, vaccines, food, etc.). These tiny, invisible animals can help us understand the fundamental principles of the nature of living systems. So be careful when walking on the grass.