"How different animals eat" - Ways of feeding different animals. Herbivores are animals that need plant food. Confusion game. Here is a shy deer at the edge, he is not too lazy to pluck the grass. What a terrible predator. All butterflies are characterized by the presence of a long movable proboscis. Fascinating excursion. Crayfish. Types of teeth. Bee. We are in the meadow. Animals. Prudovik. How does a whale eat? These animals are helped to feed by teeth that bite off.

"Skin diseases in animals" - Endogenous factors. Ulcer. granulation barrier. Warty dermatitis. Furuncle in a dog. Clinical signs. Dermatitis of the interdigital region. Furuncles in a dog. Scar. Erythema. Seborrhea. Hydradenitis. Redness appears around the hair. The initial stage of eczema. local treatment. Significant swelling develops. Reflex eczema. Skin diseases. Eczema. Diagram of eczema formation. Bubble. folliculitis diagram.

"Trematodoses" - Helminths. pathological changes. Prevention. Trematode eggs. General form trematodes. pathogenesis and immunity. Biology of development. Pathogens. Sources of the spread of invasion. Pathogenesis. Ursovermit. Trematodoses. Paramphistomatosis. Fascioliasis. Bitionol. Common fasciola. Fallen animal. Giant fasciola. Life time diagnosis. Adolescaria. Polytrem. Niclosamide. Fasciola vulgaris. Biology of the development of paramphistomata.

"Types of protective colors" - Collective mimicry is effective. collective mimicry. transparent body. Mimicry Muller. Mimicry. Protective (cryptic) coloring. Consider animals. Eyes. Dissecting coloration. Warning coloration. Greatest effect. Threatening coloration. relative nature fitness. Mimesia. Types of protective colors of animals. Examples of eye camouflage. classical mimicry. Examples of warning coloration.

"Seasonal changes in animal life" - Colorado potato beetle. Migrations. Numbness. Textbook questions. Hibernation and torpor. Migrations reindeer. Signals. Butterfly. Bat. Cluster bats. Seasonal changes in animal life. Hibernation. Flights of birds. environment conditions.

Sections: Biology

Goals: increase the areas of knowledge of students; learn to analyze the phenomenon of temporary cessation of vital activity in living organisms, using it as a means to adapt and survive in adverse conditions.

Equipment: tables of molluscs, crustaceans, insects, fish, amphibians, reptiles, birds, mammals.

The winter season is unfavorable for many representatives of the animal and plant world, both due to low temperatures and a sharp decrease in the ability to get food. During evolutionary development many species of animals and plants have acquired peculiar adaptive mechanisms in order to survive in an unfavorable season. In some species of animals, the instinct to create food reserves has arisen and established itself; others have developed another adaptation - migration. Strikingly long flights of many species of birds, migration of some species of fish and other representatives of the animal world are known. However, in the process of evolution in many species of animals, another perfect physiological mechanism of adaptation was noticed - the ability to fall into a lifeless state at first glance, which manifests itself differently in different species of animals and has different names (anabiosis, hypothermia, etc.). Meanwhile, all these conditions are characterized by inhibition of the body's vital functions to the minimum that allows it to survive adverse winter conditions without eating. Such a state of imaginary death falls into those species of animals that are not able to provide themselves with food in winter and for them there is a danger of death from cold and hunger. And all this, developed in the process of evolution, is subject to strict natural expediency - the need to preserve the species.

Hibernation is a widespread phenomenon in nature, despite the fact that its manifestations are different in representatives of certain groups of animals, whether they are animals with unstable body temperature (poikilothermic), also called cold-blooded, in which the body temperature depends on the ambient temperature, or animals with constant temperature bodies (homeothermic), also called warm-blooded.

From among animals with unstable body temperature, various species of mollusks, crustaceans, arachnids, insects, fish, amphibians and reptiles fall into a state of hibernation, and from animals with a constant body temperature, several species of birds and many species of mammals.

How do snails hibernate?

From the soft-bodied type, many types of snails fall into hibernation (for example, all land snails). Meeting garden snails fall into hibernation in October, and it lasts until early April. After a long preparatory period, during which they accumulate the necessary nutrients in their bodies, the snails find or dig minks so that several individuals can winter together deep underground, where the temperature will be maintained at 7 - 8 ° C. Having clogged the minks well, the snails descend to the bottom and lie with the shell opening up. They then close this hole, releasing a slimy substance that soon hardens and becomes elastic (film-like). With a significant cold snap and a lack of nutrients in the body, snails burrow even deeper into the ground and form another film, thus creating air chambers that act as an excellent insulator. It has been established that during a long wintering period, snails lose more than 20% of their weight, with the largest loss occurring in the first 25-30 days. This is due to the fact that all metabolic processes gradually fade in order to reach the minimum at which the animal falls almost into a state of suspended animation with barely perceptible vital functions. During hibernation, the snail does not feed, breathing almost stops. In the spring, when the first warm days and the temperature of the soil reaches 8-10°C, when the vegetation begins to develop and the first rains fall, the snails crawl out of their winter shelters. Then begins intensive activity to restore exhausted food reserves in their body; this is expressed in the absorption of a huge amount of food compared to their body.

Water snails, pond snails, also fall into a state of hibernation - most of them burrow into the silt at the bottom of the reservoir in which they live.

Where do crayfish hibernate?

Everyone knows the threat popular among the people: "I'll show you where the crayfish hibernate!". It is believed that this proverb appeared during the time of serfdom, when the landlords, punishing the guilty serfs, forced them to catch crayfish in the winter. Meanwhile, it is known that this is almost impossible, since crayfish overwinter, deeply buried in holes at the bottom of reservoirs.

From the point of view of taxonomy, the class of crustaceans is divided into two subclasses - higher and lower crustaceans.

Of the higher crustaceans, river, marsh and lake crayfish fall into a state of hibernation. Males hibernate in groups in deep pits at the bottom, and females alone in minks, and in November they glue fertilized eggs to their short legs, from which ant-sized crustaceans hatch only in June.

Of the lower crustaceans, water fleas (genus Daphnia) are of interest. They lay, depending on the conditions, two types of eggs - summer and winter. Winter eggs have a strong shell and are formed when unfavorable living conditions occur. For some species of lower crustaceans, drying out and even freezing of eggs are necessary condition to continue their development.

Diapause in insects

By the number of species, insects surpass all other classes. Their body temperature depends on the environment, which has a strong effect on the speed of vital influences, and low temperatures greatly reduce this speed. At negative temperatures, the entire development of the insect slows down or practically stops. This anabiotic state, known as "diapause", is a reversible stoppage of developmental processes and is caused by external factors. Diapause occurs when conditions are unfavorable for life and continues throughout the winter, until conditions become more favorable with the onset of spring.

The onset of the winter season different types insects at different stages of their development, in which they hibernate - in the form of eggs, larvae, pupae or adult forms, but usually each individual species falls into diapause at a certain stage of its development. So, for example, seven-point ladybug winters as an adult.

It is characteristic that the wintering of insects is preceded by a certain physiological preparation of their body, consisting of the accumulation of free glycerol in their tissues, which does not allow freezing. This occurs at the stage of development of the insect in which they will overwinter.

Even with the onset of the first signs of a cold snap in autumn, insects find comfortable shelters (under stones, under the bark of trees, under fallen leaves in burrows in the soil, etc.), where, after a snowfall, the temperature is moderately low and uniform.

The duration of diapause in insects is directly related to the reserves of fat in the body. The bees do not fall into a long diapause, but still at a temperature of 0 to 6 ° C they become numb and can stay in this state for 7-8 days. At lower temperatures they die.

It is also interesting how insects accurately determine the moment when they should exit the anabiotic state. Scientist N.I. Kalabukhov investigated anabiosis in some species of butterflies. He found that the duration of diapause varies from species to species. For example, the peacock butterfly was in a state of suspended animation for 166 days at a temperature of 5.9 ° C, while silkworm it took 193 days at 8.6°C. According to the scientist, even differences in the geographical area affect the duration of diapause.

Do fish hibernate?

In a peculiar way, some species of a large class of fish adapt to low water temperatures in winter. normal temperature the body of fish is not constant and corresponds to the temperature of the water. With a sudden sharp drop in water temperature, the fish fall into a state of shock. It is enough, however, that the water warms up, and they quickly “come to life”. Experiments have shown that frozen fish come to life only when their blood vessels are not frozen.

Originally adapted to low water temperatures in winter, some fish that live in Arctic waters: they change their blood composition. With a decrease in water temperature in autumn, salts accumulate in their blood in such a concentration that is typical for sea ​​water, while the blood freezes with great difficulty (a kind of antifreeze).

From freshwater fish back in November, carp, ruff, perch, catfish and others fall into hibernation. When the water temperature drops below 8 - 10°C, these fish move to the deeper parts of the reservoirs, burrow large groups in the silt and remain there in a state of hibernation throughout the winter.

Some sea ​​fish also tolerate severe cold in a state of hibernation. So, for example, herring is already approaching the coast in autumn. Arctic Ocean to fall into a state of hibernation at the bottom of some small creek. The Black Sea anchovy also winters in the southern regions of the sea - off the coast of Georgia, at this time it is not active and does not consume food. And the Azov anchovy before the onset of the winter period migrates to the Black Sea, where it gathers in groups in a relatively sedentary state.

Hibernation in fish is characterized by their extremely limited activity, complete cessation of feeding, and a sharp decrease in metabolism. At this time, their body is supported by the reserves of nutrients accumulated due to abundant nutrition in the autumn.

hibernation of amphibians

In terms of lifestyle and structure, the class of amphibians is transitional between typically aquatic vertebrates and typically terrestrial animals. It is known that various types of frogs, newts, salamanders also spend the unfavorable winter season in a state of stupor, as these are animals with unstable body temperature, which depends on the ambient temperature.

Determined that hibernation frogs lasts from 130 to 230 days and its duration depends on the duration of winter.

In reservoirs, in order to overwinter, frogs gather in groups of 10-20 specimens, burrow into silt, into underwater depressions and other voids. During hibernation, frogs breathe only through their skin.

In winter, newts usually nestle under warm, rotten stumps and trunks of fallen trees. If they do not find such convenient "apartments" nearby, they are satisfied with cracks in the soil.

Reptiles hibernate too

From the class of reptiles, almost all species of our fauna fall into a state of hibernation in winter. Low winter temperatures is the main reason for this phenomenon.

Winter quarters are usually underground caverns or voids formed around large old stumps with rotten roots, crevices in rocks, and other places that are not accessible to their enemies. In such shelters, a large number of snakes gather, forming huge coils of snakes. It has been established that the temperature of snakes during hibernation almost does not differ from the ambient temperature.

Most species of lizards (meadow, striped, green, forest, spindle) also hibernate, burrowing into the soil, into burrows that are not threatened by flooding. In warm sunny days in winter, lizards can “wake up” and crawl out of their winter shelters for several hours to hunt, after which they again hide in their minks, falling into a state of stupor.

Bog turtles spend the winter burrowing into the silt of the reservoirs in which they live, while land turtles climb to a depth of 0.5 m into the soil into some natural shelters or holes of moles, foxes, rodents, covering themselves with peat, moss and wet leaves.

Preparation for wintering begins in October, when turtles accumulate fat. In the spring, with temporary warming, they wake up, sometimes for a whole week.

Are there birds that hibernate in winter?

Most animals with unstable body temperature, which depends on the environment, fall into a state of hibernation. But surprisingly, many animals with a constant body temperature, such as birds, can also hibernate during the unfavorable seasons of the year. It is known that most birds avoid adverse winter conditions by migrating. Even Aristotle, in his multi-volume History of Animals, drew attention to the fact that “some of the birds fly away to spend the winter in warm countries, while others take refuge in various shelters, where they fall into hibernation.”

The great Swedish naturalist Karl Linnaeus also came to this conclusion, who in his work “The System of Nature” wrote: “In autumn, when the cold starts, swallows, not finding enough insects for food, begin to seek shelter for wintering in reed beds along the banks of lakes and rivers.”

The torpor into which some species of birds fall is quite different from the hibernation common to many mammals. First of all, the body of birds not only does not accumulate energy reserves in the form of fat, but, on the contrary, consumes a significant part of them. While mammals go into hibernation, having noticeably gained weight, birds lose a lot of weight before stupor. That is why the phenomenon of torpor in birds, according to the Soviet biologist R. Potapov, should be called not hibernation, but hypothermia.

Until now, the mechanism of hypothermia in birds is not fully understood. The fall of birds into a state of stupor under adverse living conditions is an adaptive physiological reaction that has been fixed in the process of evolution.

What mammals hibernate in winter?

As in the animals discussed earlier, so in mammals, hibernation is a biological adaptation to survive the unfavorable season of the year. Although animals with a constant body temperature usually tolerate cold climates, the lack of suitable food in winter has caused some of them to acquire and gradually consolidate in the course of evolution this peculiar instinct - to spend an unfavorable winter season in an inactive state of hibernation.

There are three types of hibernation according to the degree of torpor:

1) slight torpor, which easily stops (raccoons, badgers, bears, raccoon dogs);

2) complete stupor, accompanied by periodic awakenings only on warmer winter days (hamsters, chipmunks, bats);

3) real incessant hibernation, which is a stable, prolonged stupor (ground squirrels, hedgehogs, marmots, jerboas).

Winter hibernation of mammals is preceded by a certain physiological preparation of the organism. It consists primarily in the accumulation of fat reserves, mainly under the skin. Some people who hibernate in winter have as much as 25% body fat. total mass body. For example, ground squirrels get fat at the beginning of autumn, increasing their body weight three times compared to spring-summer weight. Before hibernation, both hedgehogs and brown bears, as well as all the bats.

Other mammals, such as hamsters and chipmunks, do not accumulate large stores of fat, but store food in their shelter to use during their brief periods of awakening in winter.

During hibernation, all species of mammals lie motionless in their burrows, curled up into a ball. So it is best to keep warm and limit heat exchange with environment. Zimnik apartments of many mammals are natural emptiness of stems and tree hollows.

From insectivorous mammals hedgehog, preparing for hibernation, collects moss, leaves, hay in a secluded place and makes a nest for itself. But he “settles” in his new home only when the temperature for a long time is kept below 10 ° C. Before that, the hedgehog eats plentifully in order to accumulate energy in the form of fat.

Hibernation brown bears is a slight numbness. In nature, in the summer, a bear accumulates a thick layer of subcutaneous fat and, immediately before the onset of winter, settles in its lair for hibernation. Usually the lair is covered with snow, so it is much warmer inside than outside. During hibernation, the accumulated fat reserves are used by the bear's body as a source of nutrients, and also protect the animal from freezing.

From a physiological point of view, the hibernation of mammals is characterized by the weakening of all vital functions of the body to the minimum that would allow them to survive adverse winter conditions without food.

Change of seasons in temperate zone entails significant changes in the life of nature, associated primarily with changes in temperature. Adaptations of plants and animals associated with change external conditions, have different shape and manifestations: in mammals, a thick undercoat grows, migratory birds change their habitat, other birds are covered with down, which is a poor conductor of heat and protects animals from hypothermia in winter.

Preparing for winter

In the middle of summer, the growth of many plant species stops, the number flowering plants, bird breeding ends. The ripening of fruits and seeds begins; getting ready for winter.

Plants accumulate reserve nutrients in overwintering organs: roots, rhizomes, bulbs, tubers.

In insects, fat accumulates in special organs - fat bodies. Fat is also deposited in the subcutaneous tissue of many mammals. In autumn, birds and mammals molt. Leaves fall from trees and shrubs.

A state of deep rest

Many types of organisms have acquired the ability to survive adverse conditions (high or very low temperatures, reduced humidity, lack of food, etc.) in a state of deep dormancy. It is characterized by a decrease in physiological processes, a slowdown in gas exchange, cessation of nutrition and immobility in animals.

The temperature that causes this condition is different for different species. In some insects, fish and amphibians, deep dormancy occurs already when the temperature drops to + 15 ° C, in others - at + 10 ° C, in others - only at a temperature close to 0 ° C.

In different plant species, different organs experience the state of winter dormancy. In bulbous plants - bulbs, in ferns and a number of others - rhizomes, in sweet peas - underground tubers, in thistles - rosettes of leaves pressed to the ground, in most plants - seeds.

Invertebrates can overwinter at various stages of development. Yes, ordinary malarial mosquito- at the stage of an adult insect, spring - at the stage of the larva, hollow - at the stage of the egg, and cabbage butterfly - at the stage of the pupa.

During autumn and winter, plants and insects become more accustomed to cold, and resistance to low temperatures. This is called hardening.

Anabiosis of animals and plants

Organisms in a state of suspended animation have a special resistance to adverse conditions. During anabiosis, life processes are temporarily stopped or so reduced that there are no visible manifestations of life.

In flowering plants, the state of anabiosis is included in the normal cycle of life. Dried seeds remain viable for many years. In a number of invertebrates (protozoa, lower crustaceans, rotifers), anabiosis occurs when the puddles and swamps in which they live dry out.

Other invertebrates go into suspended animation when frozen. Protozoa, some arthropods (daphnia, cyclops, insects) can freeze into ice.

In specially designed experiments, butterfly caterpillars survived freezing at a temperature of -7.9°C, and roundworms-183°C. Moss and fern spores and cereal seeds after drying were subjected to a temperature of -272°C and retained their germination.

It has been established that a return to active life from the state of suspended animation is possible only when the tissue fluid does not form crystals, but remains in a supercooled state. This is due to the fact that glycerin is formed in the tissues, which prevents freezing.

Physiology of hibernation

The decrease in metabolic rate that occurs in mammals manifests itself in the form of hibernation. The reasons for its onset are a decrease in temperature, as well as the lack of food both in winter and in summer, when the vegetation in the steppe and desert burns out from the heat.

Hamsters, chipmunks, bats, hedgehogs, some types of ground squirrels fall into winter hibernation. Other ground squirrel species have hibernation, usually during the dry half of the summer. During hibernation, active thermoregulation decreases, body temperature drops almost to ambient temperature, and all functions slow down. The heart rate of bats, for example, drops from 420 to 16 per minute.

In some mammals - bears, badgers, raccoon dogs, squirrels - winter sleep occurs, during which metabolism is also significantly reduced, but there is no drop in body temperature.

Special fixtures

To complete life cycle some plants, insects, and a number of other organisms need to cool down and go through winter dormancy stages. At this time, certain physiological processes are carried out that prepare the body for a new active life.

Ways of experiencing by living organisms adverse conditions(wintering, hibernation, suspended animation, migration, etc.).

Wintering- ways to deal with adversity winter period(low temperatures, lack of food) animals of temperate and cold zones. Invertebrates have development cycles, where one of the phases is cold-resistant (example: locust eggs, beetle larvae, butterfly pupae). In warm-blooded animals - hibernation (hibernation) - bear, hedgehog, badger - during it biological processes slow down. In plants, wintering is accompanied by a cessation or a sharp slowdown of physiological processes. The physiological meaning is the conservation of energy in adverse conditions. Summer hibernation is associated with seasonal moisture deficiency (estivation) - lungfish.

Anabiosis- a state of the body in which physiological processes are temporarily stopped or so slowed down that there are no visible manifestations of life, observed with a sharp deterioration in the conditions of existence - low temperature, drought. When conditions are favorable, recovery normal level vital activity, cysts are the most resistant. In poikilotherms - amphibians (toads, frogs, newts) - long-term exposure high temperatures for awakening. Diapause - special case anabiosis, insects are observed - larval (in hawthorn), pupal, imaginal (mosquito) diapause.

Winter dream - inhibition in the cerebral cortex and subcortical areas, accompanied by a decrease in metabolism. Winter sleep allows animals to survive the unfavorable period

of the year. Winter sleep differs from hibernation by the lower intensity of the process of inhibition of all functions and the ability to wake up.

Emigration- This is a mass migration of animals from their usual habitats.

Kochevka- short-term and short-term movement of animals from one area to another as an adaptation to the experience of adverse living conditions. There are seasonal, periodic and random forms of nomadism. Reason: winter, drought, wintering, in herbivorous ungulates - the availability of food. At the same time, during migrations, animals do not always return to their original places, different routes are observed.

Migration- periodic or non-periodic, horizontal and vertical regular movements of animals to an individual habitat of an individual (their group) for a season, year or a number of years. Its features: strict seasonality, the presence of a mechanism for controlling its calendar dates, multiple restructuring physiological systems Due to the upcoming increase in energy consumption, the need for orientation in space, individuals in a certain physiological state are involved in migration, mass character associated with the synchronization of the timing of the development of the migratory state in all individuals. Seasonal migration is known for many taxa of animals, most well studied in birds, as well as spawning migrations of fish. Distinguish active, passive, fodder, resettlement and other forms of animal migration.

47. Structure of populations: spatial and demographic.

The main indicators of the structure of populations - the number, distribution of organisms in space and the ratio of individuals of different quality. Each individual has a certain size, gender, distinctive features morphology, behavioral features, their limits of endurance and adaptability to environmental changes. The distribution of these traits in a population also characterizes its structure. The structure of the population is not stable. The growth and development of organisms, the birth of new ones, death from various causes, changes in environmental conditions, an increase or decrease in the number of enemies - all this leads to a change in various ratios within the population.

Causes of imaginary death (anabiosis) in plant and animal organisms

allowing them to survive adverse winter conditions.

O.K. Smirnova, teacher of biology of the highest category of Lyceum No. 103, Rostov-on-Don.

Goals: increase the areas of knowledge of students; learn to analyze the phenomenon of temporary cessation of vital activity in living organisms, using it as a means to adapt and survive in adverse conditions.

Equipment: tables of mollusks, crustaceans, insects, fish, amphibians, reptiles, birds, mammals.

The winter season is unfavorable for many representatives of the animal and plant world, both due to low temperatures and a sharp decrease in the ability to get food. In the course of evolutionary development, many species of animals and plants have acquired peculiar adaptive mechanisms in order to survive in an unfavorable season. In some species of animals, the instinct to create food reserves has arisen and established itself; others have developed another adaptation - migration. Strikingly long flights of many species of birds, migration of some species of fish and other representatives of the animal world are known. However, in the process of evolution in many species of animals, another perfect physiological mechanism of adaptation was noticed - the ability to fall into a lifeless state at first glance, which manifests itself differently in different species of animals and has different names (anabiosis, hypothermia, etc.). Meanwhile, all these conditions are characterized by inhibition of the body's vital functions to the minimum that allows it to survive adverse winter conditions without eating. Such a state of imaginary death falls into those species of animals that are not able to provide themselves with food in winter and for them there is a danger of death from cold and hunger. And all this, developed in the process of evolution, is subject to strict natural expediency - the need to preserve the species.

Hibernation is a widespread phenomenon in nature, despite the fact that its manifestations are different in representatives of certain groups of animals, whether they are animals with a variable body temperature (poikilothermic), also called cold-blooded, in which the body temperature depends on the ambient temperature, or animals with a constant body temperature (homeothermic), also called warm-blooded.

From among animals with unstable body temperature, various species of mollusks, crustaceans, arachnids, insects, fish, amphibians and reptiles fall into a state of hibernation, and from animals with a constant body temperature, several species of birds and many species of mammals.

How do snails hibernate?

From the soft-bodied type, many types of snails fall into hibernation (for example, all land snails). Encountered garden snails hibernate in October, and it lasts until early April. After a long preparatory period, during which they accumulate the necessary nutrients in their bodies, the snails find or dig minks so that several individuals can winter together deep underground, where the temperature will be maintained at 7 - 8 ° C. Having clogged the minks well, the snails descend to the bottom and lie with the shell opening up. They then close this hole, releasing a slimy substance that soon hardens and becomes elastic (film-like). With a significant cold snap and a lack of nutrients in the body, the snails burrow even deeper into the ground and form another film, thus creating air chambers that play the role of an excellent insulator. It has been established that during a long wintering period, snails lose more than 20% of their weight, with the largest loss occurring in the first 25-30 days. This is due to the fact that all metabolic processes gradually fade in order to reach the minimum at which the animal falls almost into a state of suspended animation with barely perceptible vital functions. During hibernation, the snail does not feed, breathing almost stops. In the spring, when the first warm days come and the soil temperature reaches 8-10°C, when the vegetation begins to develop and the first rains fall, the snails come out of their winter shelters. Then begins intensive activity to restore exhausted food reserves in their body; this is expressed in the absorption of a huge amount of food compared to their body.

Water snails, pond snails, also fall into a state of hibernation - most of them burrow into the silt at the bottom of the reservoir in which they live.

Where do crayfish hibernate?

Everyone knows the popular threat among the people: "I'll show you where the crayfish hibernate!". It is believed that this proverb appeared during the time of serfdom, when the landlords, punishing the guilty serfs, forced them to catch crayfish in the winter. Meanwhile, it is known that this is almost impossible, since crayfish overwinter, deeply buried in holes at the bottom of reservoirs.

From the point of view of taxonomy, the class of crustaceans is divided into two subclasses - higher and lower crustaceans.

Of the higher crustaceans, river, marsh and lake crayfish fall into a state of hibernation. Males hibernate in groups in deep pits at the bottom, and females alone in minks, and in November they glue fertilized eggs to their short legs, from which ant-sized crustaceans hatch only in June.

Of the lower crustaceans, water fleas (genus Daphnia) are of interest. They lay, depending on the conditions, two types of eggs - summer and winter. Winter eggs have a strong shell and are formed when unfavorable living conditions occur. For some species of lower crustaceans, drying out and even freezing of eggs is a necessary condition for the continuation of their development.

Diapause in insects.

By the number of species, insects surpass all other classes. Their body temperature depends on the environment, which has a strong effect on the speed of vital influences, and low temperatures greatly reduce this speed. At negative temperatures, the entire development of the insect slows down or practically stops. This anabiotic state, known as "diapause", is a reversible cessation of developmental processes and is caused external factors. Diapause occurs when conditions are unfavorable for life and continues throughout the winter, until conditions become more favorable with the onset of spring.

The onset of the winter season finds different types of insects at different stages of their development, in which they winter - in the form of eggs, larvae, pupae or adult forms, but usually each individual species falls into diapause at a certain stage of its development. So, for example, the seven-spotted ladybug hibernates as an adult.

It is characteristic that the wintering of insects is preceded by a certain physiological preparation of their body, consisting of the accumulation of free glycerol in their tissues, which does not allow freezing. This occurs at the stage of development of the insect in which they will overwinter.

Even with the onset of the first signs of a cold snap in autumn, insects find comfortable shelters (under stones, under the bark of trees, under fallen leaves in burrows in the soil, etc.), where, after a snowfall, the temperature is moderately low and uniform.

The duration of diapause in insects is directly related to the reserves of fat in the body. Bees do not fall into a long diapause, but still at a temperature of 0 to 6 ° C they become numb and can stay in this state for 7-8 days. At lower temperatures they die.

It is also interesting how insects accurately determine the moment when they should exit the anabiotic state. Scientist N.I. Kalabukhov investigated anabiosis in some species of butterflies. He found that the duration of diapause varies from species to species. For example, the peacock butterfly was in a state of suspended animation for 166 days at a temperature of 5.9 ° C, while the silkworm needed 193 days at a temperature of 8.6 ° C. According to the scientist, even differences in the geographical area affect the duration of diapause.

Do fish hibernate?

In a peculiar way, some species of a large class of fish adapt to low water temperatures in winter. Normal body temperature in fish is not constant and corresponds to the temperature of the water. With a sudden sharp drop in water temperature, the fish fall into a state of shock. It is enough, however, for the water to warm up, and they quickly “come to life”. Experiments have shown that frozen fish come to life only when their blood vessels are not frozen.

Originally adapted to low water temperatures in winter, some fish that live in Arctic waters: they change their blood composition. With a decrease in water temperature in autumn, salts accumulate in their blood in such a concentration that is characteristic of sea water, and at the same time the blood freezes with great difficulty (a kind of antifreeze).

From freshwater fish, carp, ruff, perch, catfish and others fall into hibernation in November. When the water temperature drops below 8 - 10°C, these fish move to the deeper parts of the reservoirs, burrow into the silt in large groups and remain there in a state of hibernation throughout the winter.

Some marine fish also endure extreme cold while hibernating. So, for example, herring already in autumn approach the coast of the Arctic Ocean in order to fall into a state of hibernation at the bottom of some small bay. The Black Sea anchovy also winters in the southern regions of the sea - off the coast of Georgia, at this time it is not active and does not consume food. And the Azov anchovy before the onset of the winter period migrates to the Black Sea, where it gathers in groups in a relatively sedentary state.

Hibernation in fish is characterized by their extremely limited activity, complete cessation of feeding, and a sharp decrease in metabolism. At this time, their body is supported by the reserves of nutrients accumulated due to abundant nutrition in the autumn.

hibernation of amphibians

In terms of lifestyle and structure, the class of amphibians is transitional between typically aquatic vertebrates and typically terrestrial animals. It is known that various types of frogs, newts, salamanders also spend the unfavorable winter season in a state of stupor, as these are animals with unstable body temperature, which depends on the ambient temperature.

It has been established that the hibernation of frogs lasts from 130 to 230 days and its duration depends on the duration of winter.

In reservoirs, in order to overwinter, frogs gather in groups of 10-20 specimens, burrow into silt, into underwater depressions and other voids. During hibernation, frogs breathe only through their skin.

In winter, newts usually nestle under warm, rotten stumps and trunks of fallen trees. If they do not find such convenient "apartments" nearby, they are satisfied with cracks in the soil.

Reptiles hibernate too

From the class of reptiles, almost all species of our fauna fall into a state of hibernation in winter. Low winter temperatures are the main reason for this phenomenon.

Winter quarters are usually underground caverns or voids formed around large old stumps with rotten roots, crevices in rocks, and other places that are not accessible to their enemies. In such shelters, a large number of snakes gather, forming huge coils of snakes. It has been established that the temperature of snakes during hibernation almost does not differ from the ambient temperature.

Most species of lizards (meadow, striped, green, forest, spindle) also hibernate, burrowing into the soil, into burrows that are not threatened by flooding. On warm sunny days in winter, the lizards may "awaken" and crawl out of their winter shelters for several hours to hunt, after which they again hide in their burrows, falling into a state of torpor.

Bog turtles spend the winter burrowing into the silt of the reservoirs in which they live, while land turtles climb to a depth of 0.5 m into the soil into some natural shelters or holes of moles, foxes, rodents, covering themselves with peat, moss and wet leaves.

Preparation for wintering begins in October, when turtles accumulate fat. In the spring, with temporary warming, they wake up, sometimes for a whole week.

Are there birds that hibernate in winter?

Most animals with unstable body temperature, which depends on the environment, fall into a state of hibernation. But surprisingly, many animals with a constant body temperature, such as birds, can also hibernate during the unfavorable seasons of the year. It is known that most birds avoid adverse winter conditions by migrating. Even Aristotle, in his multi-volume History of Animals, drew attention to the fact that “some birds fly away to spend the winter in warm countries, while others take refuge in various shelters where they hibernate.”

The great Swedish naturalist Karl Linnaeus also came to this conclusion, who in his work “The System of Nature” wrote: “In autumn, when the cold starts, swallows, not finding enough insects for food, begin to seek shelter for wintering in reed beds along the banks of lakes and rivers.”

The torpor into which some species of birds fall is quite different from the hibernation common to many mammals. First of all, the body of birds not only does not accumulate energy reserves in the form of fat, but, on the contrary, consumes a significant part of them. While mammals go into hibernation, having noticeably gained weight, birds lose a lot of weight before stupor. That is why the phenomenon of torpor in birds, according to the Soviet biologist R. Potapov, should be called not hibernation, but hypothermia.

Until now, the mechanism of hypothermia in birds is not fully understood. The fall of birds into a state of stupor under adverse living conditions is an adaptive physiological reaction that has been fixed in the process of evolution.

What mammals hibernate in winter?

As in the animals discussed earlier, so in mammals, hibernation is a biological adaptation to survive the unfavorable season of the year. Although animals with a constant body temperature usually tolerate cold climates, the lack of suitable food in winter has caused some of them to acquire and gradually consolidate in the course of evolution this peculiar instinct - to spend an unfavorable winter season in an inactive state of hibernation.

There are three types of hibernation according to the degree of torpor:

1) slight torpor, which easily stops (raccoons, badgers, bears, raccoon dogs);

2) complete stupor, accompanied by periodic awakenings only on warmer winter days (hamsters, chipmunks, bats);

3) real incessant hibernation, which is a stable, prolonged stupor (ground squirrels, hedgehogs, marmots, jerboas).

Winter hibernation of mammals is preceded by a certain physiological preparation of the organism. It consists primarily in the accumulation of fat reserves, mainly under the skin. In some winter sleepers, subcutaneous fat reaches 25% of the total body weight. For example, ground squirrels get fat at the beginning of autumn, increasing their body weight three times compared to spring-summer weight. Before hibernation, hedgehogs and brown bears, as well as all bats, get significantly fatter.

Other mammals, such as hamsters and chipmunks, do not accumulate large stores of fat, but store food in their shelter to use during their brief periods of awakening in winter.

During hibernation, all species of mammals lie motionless in their burrows, curled up into a ball. So it is best to keep warm and limit heat exchange with the environment. Zimnik apartments of many mammals are natural emptiness of stems and tree hollows.

From insectivorous mammals, the hedgehog, preparing for hibernation, collects moss, leaves, hay in a secluded place and arranges a nest for itself. But it “settles” in its new home only when the temperature is kept below 10 ° C for a long time. Before that, the hedgehog eats abundantly in order to store energy in the form of fat.

Winter hibernation of brown bears is a slight stupor. In nature, in the summer, a bear accumulates a thick layer of subcutaneous fat and, immediately before the onset of winter, settles in its lair for hibernation. Usually the lair is covered with snow, so it is much warmer inside than outside. During hibernation, the accumulated fat reserves are used by the bear's body as a source of nutrients, and also protect the animal from freezing.

From a physiological point of view, the hibernation of mammals is characterized by the weakening of all vital functions of the body to the minimum that would allow them to survive adverse winter conditions without food.