Amphibians - interesting facts. Amphibians are amazing creatures

1. Some amphibians in arid areas are able to produce liquid themselves in the form of dew. For example, the coral-footed litoria, a frog that lives in Australia, can get out of a warm shelter outside at night. There it cools and then returns, after which condensation forms on its body, which the frog absorbs over the entire surface of its skin.

2. The smallest representative of frogs lives in Cuba and measures only 8.5 mm. While the largest - the African Goliath (pictured above) - reaches a length (excluding paws) of 30 cm and a weight of three kilograms. Such impressive dimensions do not prevent it from jumping a distance of three meters, but at the same time, thanks to them, it has become an object of hunting for local residents and is therefore endangered

3. B South America There lives an amazing toad, she herself is small, only 4-5 cm, but her offspring (tadpoles) outgrow their mother by 3-4 times. But as they grow older, they return to standard sizes. This species is called the “paradoxical frog” for this feature.

4. Green algae are added to the eggs that the salamander lays. This is a mutually beneficial symbiosis. The embryo receives oxygen from the plant. The algae feeds on nitrogen, which contains waste from the embryo. Everyone knows about the fire salamander; it has a characteristic color (black with bright yellow spots). She is characterized by viviparity, and amazing ability not to burn in fire, which has long become the subject of legends. The explanation is simple: the salamander’s body is covered with special mucus and this allows it to gain time and retreat. The largest representative of this order lives in Japan (pictured). It is called a giant salamander and averages one meter in length. This is a predator that resembles some kind of prehistoric creature. Possessing poor eyesight, he orients himself in space using the senses of smell and touch.

5. There are legless amphibians. To put it mildly, this strange creatures, reminiscent of snakes and earthworms at the same time. This is the smallest order of amphibians known since Jurassic period. They have no limbs, and the tail is greatly reduced. Their skin is completely bare, although some have noticeable reduced scales; the color is usually dark and matte. These are inhabitants of the forest floor near water bodies; some are characterized by viviparity.

6. Frog Rheobatrachus silus or Caring frog. Got its name thanks to its ability carry offspring in the stomach until they are fully mature. The female swallows the fertilized eggs, and after a while spits out the little frogs. According to the results of the research, it turned out that tadpoles produce a special substance - prostaglandin E2, which does not allow the release of stomach acid, which allows the tadpoles to develop calmly inside the frog. Unfortunately, this species is considered endangered due to environmental changes.

7. Length the smallest frog in the world is only 10-13 mm, and females are slightly larger than males. It also has a camouflage color, so it will take a lot of effort to see it. It was discovered by scientists Alessandro Catenazzi and Edgar Lehr in 2008. In her entire life, she lays only 2 eggs, which are the size of a third of a frog’s body. It lives in one territory, almost never leaving it.

8. The largest salamander lives in the rivers and lakes of Eastern China. Its length is 150-180 cm, and its weight is about 65 kg. Considered to be the largest amphibian. Nowadays it is on the verge of extinction, because for normal existence it urgently needs clean and cold water, and due to constant pollution this becomes difficult.

9. Frogs dart frogs and leaf frogs have a very bright color. In addition, they are considered the most poisonous vertebrates on earth. The skin glands of these frogs secrete poison in microscopic sizes, which has a nerve-paralytic effect, and this amount is enough to kill large predator.

10. There is a world glass frog. At first glance, it is no different from ordinary green frog, but you should pay attention to its belly, the skin on it resembles glass, through which you can see all the internal organs.

11. Amazing ability crested newt to regeneration. This amphibian is capable of restoring any of the lost body parts. Newts are not afraid of frost; they can easily “wait out the cold” by freezing into the ice. And they are not afraid of the heat. Even if it seems that the newt has completely dried up, as soon as it rains, it will come to life and continue its unfinished business.

12. Do you know why in the old days it was customary to throw a frog into a bucket of milk? The fact is that there were no refrigerators at that time, and the frog’s moist skin has bactericidal properties, which is why the frog’s milk never turned sour.

13. Also the frogs' eyes play important role in...digestion. It is with the help of the eyes that the frog helps push the food in the mouth further along the digestive tract. Therefore, having captured prey, these representatives of the amphibian world must blink. And frogs close their eyes only for a short period of time, even when they sleep.

14. While in water, frogs breathe through their skin; on land, their lungs and mouth are responsible for their breathing. The body of frogs is designed in such a way that every time the animal plunges into water, it provokes a shutdown of the respiratory system. The circulatory system of frogs is also quite interesting: their heart consists of 2 sections, and mixed venous-arterial blood circulates in the body.

15. Representatives of some species (the frog Litoria nasuta, living in Australia) can overcome jumping distances 50 times their size and achieve acceleration up to 20 meters per second. Other ( Rhacophorus Nigropalmatus – Wallace's flying frogs, living in wet jungle Malaysia and Borneo) can not only jump superbly, but even glide, “flying” distances of 15 m.

The giant goliath frog is the largest representative of its species - its length is 90 cm, and its weight can exceed 3 kilograms. The goliath has very strong legs, thanks to which the average jump of this frog exceeds 3 meters.

STUDYING NEW MATERIAL.

We consider cards with the image:

Common toad, common newt, Siberian salamander.

Information on these species is provided.

Description.

GRAY TOAD.

Belongs to tailless amphibians. The gray toad is the largest toad in Europe. She has a wide, squat body and short toes on her paws. The eyes are orange with black horizontal pupils. Males do not have resonators. The skin is dry and lumpy with a small number of mucous glands, which allows the amphibian to conserve water and not dry out at a great distance from water bodies. It easily tolerates loss of moisture (it can lose up to 30% of its mass due to water evaporation without much harm). The toad stores water in its skin during night "swimmings" when the toad washes itself in the dew. It protects itself from enemies with poison, which is secreted by parotids - glands located behind the eyes. The poison acts as an emetic and only when the toad is in the enemy's mouth. lives in dry places: forests, forest-steppes, steppes, parks, gardens, bushes. The mountains rise up to 3000 m above sea level. The gray toad constantly lives on land, and in water (lakes, ditches, reservoirs, slow rivers) is included for reproduction only. It feeds on invertebrates: beetles, bedbugs, ants, slugs, worms, insect larvae, spiders, nooses, caterpillars, small snakes and lizards, newborn mice. Notices prey at a distance of up to 3 meters. Hunts with the help of a sticky tongue, to which insects stick. Hunting for big prey gray toad grabs it with his jaws, while helping himself with his paws. Despite its gluttony, it does not eat dead animals. predominantly nocturnal amphibian. During the day it hides under tree roots, stones, in grass, and rodent burrows. Most active in rainy weather, especially at night. The toad moves slowly (in steps) and jumps in case of danger. The most cold-resistant of toads. IN hibernation flows in late September-October. It overwinters under fallen leaves, logs, in burrows and drainpipes, and sometimes buries itself in coastal mud. It wakes up at the end of March, when the temperature is not lower than +5"C. After hibernation, the gray toad migrates to breeding sites. In moments of danger, it puffs up and takes an aggressive pose.
In the Omsk region it lives in the forest, sometimes in the forest-steppe zone.

The main limiting factor is the lack of suitable places for reproduction and destruction by humans.

NEWT.

The common newt is the smallest among those found in Russia. The length of the body with the tail does not exceed 9 cm, while the tail is approximately equal to or slightly longer than the body with the head. The skin is smooth or rough.

The common newt is one of the smallest newts. The skin is smooth or fine-grained. Distinguishes between red, blue-green and yellow colors. A dark longitudinal stripe passes through the eye. The tail is slightly shorter, equal to or slightly longer than body with the head. An adult newt molts once a week. The male's body is covered with large dark spots (all year round), which are absent in females. During the breeding season, the male grows a crest - an additional respiratory organ. The ridge is richly supplied with blood vessels, which significantly increases the proportion of skin respiration. The newt's crest is solid, with weak curves at the top, with an orange border and a blue stripe running underneath. The female does not develop a crest. The acquired experience is used throughout life. The sense of smell is well developed.

Color: the back is olive-brown, the underbody is yellow with small dark spots. There are longitudinal dark stripes along the head. The common newt can change color - becoming darker and lighter. Size: 8-12 cm. Life expectancy: in captivity 20-28 years. This newt is common in forests of various types, in forest-steppes, swamps, and is less common among meadows. It is not afraid of the proximity of people, easily populates human-created landscapes and, if not disturbed, thrives in parks, gardens, orchards, among pastures, rural and urban buildings, and even in landfills. The main thing is that he can find a body of water with standing or low-flowing water and places for winter shelter. Ponds are necessary for newts, since they reproduce, develop larvae, and even the adults themselves lead an aquatic lifestyle in the spring and early summer. Common newts do not have any special requirements for the quality of reservoirs. They prefer shallow ponds with clear water, densely overgrown with aquatic and coastal vegetation, inhabited by various small animals. But they can also settle in lakes, swamps, ditches, puddles, drainage basins, oxbow lakes, and water-filled pits. Common newts do not show the same pronounced attachment to their “native” (in which they were born) body of water, as some tailless amphibians do. Therefore, they quickly populate new ones that arise for one reason or another. Newts overwinter, crawling under heaps of leaves and branches, burrowing into the ground, into the passages and burrows of soil animals, and sometimes into cellars and basements. They often gather in small groups. As a rule, wintering sites are located not far from the reservoir in which newts bred - at a distance of 50-100 meters. There have been cases of wintering in non-freezing reservoirs. Sometimes the delay in the larval state is so prolonged that the newt does not undergo metamorphosis, but becomes capable of reproduction, that is, in this species, although very rarely, there are cases of neoteny. Normally, young newts that have undergone metamorphosis grow quite quickly on land and reach sexual maturity at the age of two to three years.

The common newt has many natural enemies. In water, adult but defenseless newts, as well as their larvae, are eaten by predatory insects (dragonfly larvae, swimming beetles), leeches, fish, other amphibians (for example, lake frog), snakes, and waterfowl. On land they fall prey to a wide variety of animals. In the Omsk region it lives in the forest zone.

SIBERIAN SALAMANDER.

Belongs to the tailed amphibians. Relict, very ancient amphibian in origin. It has a very dark, almost black color. Unlike a lizard, the body is covered with mucus, and bulging eyes are visible. The small newt has the largest range among all amphibians. Siberian salamander. It is found throughout almost all of Northeast Asia - in Russia, China, and Kazakhstan. But besides this, the salamander is the northernmost amphibian - it was found on the Taimyr Peninsula and Chukotka. That is, he lives in the zone permafrost.
Well-known herpetologist S. Kuzmin writes that “the salamander is a unique amphibian in its frost resistance. Adult individuals are able to tolerate temperatures dropping to -35-40°C and do not lose mobility at -1°C.
Salamanders have been repeatedly found frozen in the ice. After thawing, the animals came to life. Radiocarbon dating of the ice showed its age to be 10,000 years old. But how long did the animal spend in the ice? It feeds on various invertebrates, among which insects predominate. Wintering takes a lot of time for salamanders, because in the north of their range they have to spend up to 80% of their lives in a “suspended” state. With the arrival of warmth, at a water temperature of 2-3°C, the breeding period immediately begins. After not-
After birth, adults switch to a land-based lifestyle. Waking up early in the spring, when the ice has not yet melted, they rush to the reservoir to procreate. They spend almost their entire life on land; as we have already said, they go into the water exclusively for reproduction.

You need to choose a good shallow place with rich vegetation, and so that it is warmed by the sun. Several males hover around the female. She lays eggs, which are fertilized by the male.

The clutch is a gelatinous sac with eggs, which is attached to aquatic plants or to the stones. This is where the female's parental instinct ends. Lizards leave the aquatic environment and go to eat.

And after 3–4 weeks, salamander larvae emerge from the pouch, 10 mm long, with underdeveloped gills, but a long perioral sucker. This event takes place at the end of May.

The larvae move very slowly and sink to the bottom of the reservoir - this is the best option for survival. Within a month, the grown larvae appear on the water surface. Full development ends by the end of August, having reached 40 mm in length, the matured cubs come to land.

In the Omsk region it lives in forest and forest-steppe zones.

Limiting factors are poorly studied.

IMPORTANT: When meeting a rare amphibian in nature, you must not touch or catch it; you must leave the defenseless animal alone.

-Identify the type of amphibian using the card.

-Collect a picture of this amphibian.

-Game “Imagine a toad and a frog.” The task is given to depict how a toad and a frog move.

FIXING.

EXERCISE 1.

Name the relict tailed amphibian. It has a very dark, almost black color. Unlike a lizard, the body is covered with mucus, and bulging eyes are visible. In the Omsk region it lives in forest and forest-steppe zones. Found in wet forest (SIBERIAN ALANTERTOOK)

TASK 2.

Name a tailless amphibian. The skin is covered with mucus and pimples. In the Omsk region it lives in the forest, sometimes in the forest-steppe zone. Often found far away from the water. It feeds on various invertebrates. Moves in steps. (GRAY TOAD)

TASK 3.

Belongs to the tailed amphibians. In the Omsk region it lives in the forest zone. Males have a crest that extends from the head to the end of the tail. It is found in various reservoirs, lakes, and swamps. It feeds on various invertebrates. (NETT)

TASK 4.

How should you behave when meeting a rare amphibian in nature?

A GAME

Complete the crossword

1. Our usual tailed amphibian.

2. A representative of the family of tailless amphibians.

3. A tailless amphibian, the development of larvae occurs in the skin cells of the dorsal part of the parent.

4. A tailed amphibian with a shiny black body color and bright yellow spots.

5. Tailless amphibian with poisonous skin glands. Lives in the forests of Central and South America.

6. Tailless amphibian leading an arboreal lifestyle.

7. Tailless amphibian, with a brightly colored belly.

8. A toad with a peculiar care for its offspring.

10. A tailed amphibian with three pairs of external gills.

11. Tailless amphibian, there are small teeth on the upper jaw

Station: "Terminal"

LEADING: We all successfully reached the Konechnaya station, let's remember what we learned and repeated as we moved from station to station.

Questions for all teams

What is the Red Book? ( The Red Book is a book that contains information about rare and endangered plants and animals)

– What did the first Red Book look like? (The cover was red, and the pages were multi-colored: red, yellow, white, gray and green)

– In what year was the International Red Book published? (In 1966)

– Why did you choose red for its cover? (Red color is a danger signal)

– Why did you choose multi-colored pages in this book? (In order to see the position of this or that animal and plant: endangered, persistent, rare, uncertain and recovering)

– What types of plants and animals are included in this book? (Rare and endangered)

– For what reason can plants and animals change their location in the Red Book? (If the fate of an animal or plant changes for the better or for the worse)

Using the code, decipher the name of the topic.

169, 4585397 956230!

– DECODING: Be nature's friend!

– If you want to see a lot of interesting things in nature and hear the singing of birds, the buzzing of insects, the squeak of a wood mouse - hide, don’t make noise, listen to the rustles and sounds. You are visiting nature, remember this!

Why are many plants and animals becoming increasingly rare? (Children list: they kill animals, cut down forests, catch fish with nets, catch butterflies with nets, pick flowers, drain factories dirty water into bodies of water).

Well done, you answered correctly!

– The protection of plants and animals is a state problem, but can you and I help nature, become its friend? (We can: we won’t pick flowers, break trees, destroy nests, etc.)

Amphibians were the first to master land, but did not lose touch with the water element. These animals are a consequence of the evolution of freshwater lobe-finned fish that lived on the planet about 300 million years ago, mainly in wetlands.

Basic characteristics of amphibians

We can identify a number of basic characteristics that are inherent in almost all representatives of this genus:

• the body has a slightly flattened shape;
• paws have five toes;
• the skin is moist, thin, with a huge number of sebaceous glands;
• all animals of this class are predators;
• the heart has three chambers;
• adults have two respiratory organs - lungs and skin, larvae breathe through gills.

Species diversity

An interesting fact about amphibians is that they have minimal practical significance, at the same time, there is still a certain benefit for humans - they destroy harmful arthropods, slugs and mollusks.

There are two groups living on the territory of our country:

Eating frogs and salamanders is acceptable in some regions. Newts feed on mosquito larvae, including malaria mosquitoes. Most often, experiments are performed on frogs; on the other hand, they also cause harm, since they are “lovers” of fish fry.

frogs

This is a commonly used concept for an entire order of anurans. In a narrow sense, this term applies to the family of true frogs. The minimum size of the animal is 9 mm, and the largest individuals can reach 90 cm, and they include the goliath frog. And the smallest lives in Cuba, its size is only 9 mm. All species of frogs have bulging eyes and stocky bodies.

But few people know an interesting fact about amphibians - frogs have teeth, but they are intended solely for grasping and holding, and not for chewing. And toads have no teeth at all.

All frogs have unique vision, being able to simultaneously look in different directions with both eyes. These amphibians do not close their eyes for a long time, even when they sleep.

An interesting fact about amphibians is that their skin has antibacterial and disinfecting properties, so in Rus' it was customary to throw frogs into milk to prevent it from turning sour.

There is such a thing as “functional necrophilia”; this phenomenon occurs in Amazonian necrophilic frogs. There are 10 times more males of this species than females, so they fertilize not only the eggs of living individuals, but also dead ones. And the caring frog carries her babies in her own stomach until they are fully mature. In practice, it looks like this: the female swallows the fertilized eggs, and as soon as they are ready to live on their own, the frog spits them out.

Interesting Facts about amphibians and amphibians:

• There is such a species as a glass frog; the skin on its belly resembles a glass surface through which all organs can be seen.
• The most poisonous are leaf climbers and dart frogs. The venom of these amphibians is capable of knocking down a large predator.
• Some species of frogs are capable of removing foreign objects from their bodies. This foreign object practically becomes overgrown with “meat”, enters the bladder and is removed from there.

Humanity also treats these animals differently, for example, in Japan and France they are immortalized in monuments. And in restaurants in Peru they serve a cocktail in which one of the ingredients is a still living frog. According to the local population, this drink can improve potency and get rid of asthma.

Tritons

This common name families from the order caudate. This term has no systemic connection; aquatic “newts” are those individuals that live primarily in water, and land ones are called salamanders. Interesting facts - the class of amphibians is often confused with lizards, which essentially belong to the order of reptiles.

There are only three species living in our country:

• comb;
• ordinary;
• Asia Minor.

These amphibians have a beautiful dorsal crest and a yellow or orange abdomen. The female has to carefully hide her offspring. If there is no secluded place in the pond nearby, then she wraps the eggs in leaves and only then lowers them into the water. An interesting fact about amphibians is that newts are able to regrow a lost limb. If severe cold comes, then some individuals can practically grow into the ice, and in the spring they can live as before, without any damage to their health. During very dry periods, the newt practically dries out, but after the first rain it is instantly restored.

Salamanders

In our country the most common type is fire salamander. They have bright spots on their bodies, and glands around their eyes secrete a poisonous liquid. If it gets on the human mucous membrane, it will inevitably cause a burning sensation.

An interesting fact is that tailed amphibians do not like the cold, so for the winter they gather in large groups, near the roots under a huge layer of fallen leaves. In cold weather, amphibians practically do not move.

The largest individuals are found in the reservoirs of Eastern China; this species is called the giant salamander. It can weigh about 70 kg and reach 2 meters in length.

It was previously believed that salamanders were poisonous; in fact, the poison, which is secreted from the glands around the eyes, can only paralyze the victim for a while or cause cardiac arrhythmia. But even in the presence of poison, this amphibian is hunted by some fish, birds and even wild boars. The salamanders themselves eat insects, but do not disdain small newts and frogs.

An interesting fact is that this class of amphibians swims very poorly, and in deep water they can even drown. Therefore, they need water exclusively for laying eggs.

Worms

This is the least studied amphibian, but there are about 100 species of caecilians. This animal lives underground, although it can exist on land and in water. Interesting facts about amphibians - caecilians have no eyes, very poor hearing, but a great sense of smell. Mostly all species are dark in color, but blue and yellow are also found. Amphibians feed on mollusks and earthworms and live mainly in tropical forests.

Today, amphibians or amphibians are on the verge of extinction. They are too dependent on water, have small sizes and permeable skin. Most of it is under direct anthropogenic influence person. Another danger for amphibians is chytridiomycete fungi, the abundant growth of which is associated with an increase in atmospheric temperature on the planet.

Frogs, in the narrow sense, refer to only representatives of the family of true frogs (Ranidae).

Frogs are amphibians that inhabit almost all parts of the world. They live everywhere - in reservoirs or swamps, on the ground, even at a depth of several meters in a hard layer of clay, on trees.

Anurans move different ways. Depending on their habitat, they jump, run, walk, swim, dig holes, climb trees or glide.

Anurans are considered the best jumpers of all vertebrates (by jump length relative to body size). The Australian frog Litoria nasuta can jump more than 50 times its body length (5.5 cm). Acceleration during a jump can reach 20 m/s 2 .

A frog begins its life in water. From the eggs laid in the water, a tadpole develops, similar to a fish fry. A series of transformations of about thirty transitional stages helps the frog adapt to life on land, and the tadpole turns from a “fish” into a land animal.

The tadpole breathed through its gills, while the adult frog breathes through its mouth, lungs, and skin. Such a large set of respiratory organs is characteristic only of amphibians. While the frog is in the water, it breathes through its skin, and when it is on land, it breathes through its mouth and lungs. Versatile and circulatory system. Two parts of the heart work in water, and mixed blood flows through the body. On land, the left atrium comes into operation, and blood that is already purely arterial and saturated with oxygen enters the brain. Thus, with each dive, the frog’s respiratory organs are instantly switched off.

The skin of frogs is bare and covered with mucus, and therefore their activity depends on humidity and air temperature. It goes hunting at dusk, as the coolness increases. In cold and dry weather, frogs huddle in shelters.

Body color is affected not only by temperature, but also by background color, light, and humidity. Frogs perceive changes in these factors directly through their skin.

When wintering time comes, the frog sinks to the bottom of the reservoir.

One of the most original adaptations to living conditions in the border zone between land and water is the frog's hearing aid. It turns out that she perceives sound signals through three channels. In the air, sound waves are captured by the cells of the inner ear, through the eardrum and ear bone. Sounds traveling through the soil are perceived by the bones and muscles of the limbs and are transmitted through the bones of the skull to the inner ear.

Frogs are unpretentious and indiscriminate in their food; they can go hungry for a day or a week. They eat butterflies, bees, wasps and other moving insects. A lake frog eats fish fry.

Once the frog grabs an unsuspecting insect, it must blink: the eyelids push the eyeballs to the top of the mouth and actually help push the food down the throat. By the way, frogs have larger eyes than their stomachs.

Most frogs have teeth on the upper jaw, but these are mainly used to lock prey in the mouth and prevent it from escaping before the eyeballs push it towards the stomach.

The first monument to frogs was built at the University of Paris, at the Sorbonne, in the 19th century (pictured). It was erected (as is believed) at the insistence of the famous French naturalist Claude Bernard. This is how the scientist thanked his experimental animals. After all, he owed them a number of important discoveries.

The second monument was erected recently in Tokyo by medical students. For their experiments they used 100,000 frogs, in whose honor the monument was erected.

The largest representative of the frog world is the goliath frog (Conraua goliath). This giant frog can weigh more than three kilograms, its length is about 90 cm. The strong legs of the goliath frog allow it to make jumps three meters long.

The bullfrog, or bullfrog, is one of the largest tailless amphibians. It reaches 20.3 centimeters in length and weighs up to one and a half kilograms. This frog is one of the most common laboratory animals in North America. Thus, in 1973 alone, more than 10,000 individuals of this species were destroyed in California universities for educational and scientific purposes. But these animals are also actively eaten. Catching different ways(with fishing rods, nets, nets, traps) or by killing them with a gun, these frogs have been caught since ancient times festive table. Until now, about one hundred million bullfrogs are harvested in the United States annually. However, it is necessary to have a license to catch them and carry out it within strictly defined periods of time and by permitted methods. In the last decades of the last century, even frog farms were created. The bullfrog reaches marketable weight only in the third or fourth year of life. Only the meat of the hind limbs is eaten, which is even exported to other countries. These frogs also participate in frog races - jumping competitions. In one jump, some individuals are able to cover a distance of four meters. Bullfrogs are highly tamed. For example, when kept in groups, they learned to come to the feeding place only when people appeared in the laboratory, and on weekends the frogs did not approach the feeder. Bullfrogs are also characterized by the phenomenon of homing (from the English homing - feeling at home) - the ability to return to the place of capture after being released at some distance from it.

The smallest frogs found in Cuba have a body length of 8.5 mm to 12 mm.

Frogs' vision is designed in such a way that they can look forward, sideways and up at the same time. They never close their eyes for long, even while sleeping.

The wet skin of frogs has bactericidal properties. Our ancestors, knowing this, threw them into milk so that it would not turn sour.
However, not all types of frogs are harmless. For example, cocoi frogs, which live in the jungles of South America and Colombia, have been recognized as the most poisonous land animals on our planet. The poison of this frog is thousands of times stronger potassium cyanide and 35 times stronger than poison Central Asian cobra.

In Japan, frogs are considered a symbol of good luck.

In Ancient Egypt, frogs were a symbol of resurrection and were even mummified along with the dead. This is probably due to the fact that many species of frogs that live in temperate and cold latitudes go into hibernation every year, freezing, and are resurrected again in the spring. The fact is that frogs produce a non-freezing molecule - glucose. The liquid in the tissues becomes syrupy from frost, without forming ice crystals, which allows amphibians to survive.

The first work of art that has come down to us, the title of which includes tailless animals, is Aristophanes’ comedy “Frogs,” first staged in 405 BC. e.

• The Latin name comes from the Greek amphíbios - living a double life.

• The class Amphibians totals more than 6,700 (according to other sources - about 5,000 modern species, which makes this class relatively small.

• In Russia there are 28 species, and in the relatively small Madagascar - 247 species.

• The class Amphibians includes, among others, .

• Amphibians are the first vertebrates to transition from an aquatic to an aquatic-terrestrial lifestyle.

• Refers to the most primitive terrestrial vertebrates. Amphibians occupy an intermediate position between terrestrial and aquatic vertebrates.

• Reproduction in most species occurs in water.

• Amphibians, like , lay eggs, because their eggs (spawn) and embryos lack adaptations for terrestrial development. Development ends with Metamorphosis, during which the larvae lose their resemblance to fish and turn into adult animals.

• Adults live on land.

• The organization of Amphibians as terrestrial vertebrates is imperfect in many ways: the metabolic rate is very low, the body temperature is not constant and corresponds to the temperature of the external environment.

• All amphibians have thin, smooth skin that is relatively easily permeable to gases and liquids. Moist and soft skin plays an important role in respiration in Amphibians. Skin moisture, necessary for gas exchange, is maintained by secretions of the mucous glands. In some species, mucus can be poisonous.

• The skin is an additional organ of gas exchange and is equipped with a dense network of capillaries.

• All amphibians feed only on mobile prey. At the bottom of the oropharyngeal cavity is the tongue. When caught, the tongue is thrown out of the mouth and the prey sticks to it. The jaws have teeth that serve only to hold prey. In frogs they are located only on the upper jaw.

• All modern amphibians are predators.

• The teeth serve only to grasp and hold prey. U toads teeth are completely missing.

• There are no herbivores among amphibians due to their extremely sluggish metabolism.

• Amphibians feed on small animals (mainly insects and invertebrates) and are prone to cannibalism. U aquatic species The diet may include juvenile fish, and the largest ones prey on waterfowl chicks and small ones that fall into the water.

• IN life cycle In amphibians, four stages of development are clearly distinguished: egg, larva (tadpole), period of metamorphosis, and adult.

• For the development of the egg (spawn), it needs constant moisture. The vast majority of amphibians lay their eggs in fresh water bodies, but there are exceptions: giant salamanders, the amphium frog and some other amphibians lay eggs on land. Even in these cases, eggs need high humidity environment, the provision of which falls on the parent.

• Species are known that carry eggs on their bodies: male midwife toads wrap a cord-like clutch around their hind legs, and a female reticulated copepod attaches the eggs to her stomach.

• The fertilized eggs of the Suriname pipa are pressed by the male into the back of the female and the latter carries it on herself until young pipas hatch from the eggs.

• Larvae hatched from eggs lead an aquatic lifestyle. They resemble fish in their structure: they lack paired limbs and breathe with gills (external, then internal). Only some species are born as small tailless frogs.

• The larvae undergo metamorphosis and turn into adults leading a terrestrial lifestyle.

• Amphibians of some species take care of their offspring (toads, tree frogs).

• Fossil amphibians are much more numerous and diverse than modern ones.

Extinct amphibians: 1 – Eogyrinus; 2 – Eryops; 3 – Gerrothorax; 4 – Seymouria; 5 – Metoposaurus; 6 – Ophiderpeton; 7 – Diplocaulus; 8 – Cardiocephalus.

• But modern amphibians are also quite diverse and interesting:

Amphibians. 1 – ringed caecilian (Siphonops annulatus); 2 – proteus (Proteus anguinus); 3 – red false newt (Pseudotriton ruber): 4 – fire salamander (Salamandra salamandra); 5 – common newt (Triturus vulgaris), female, 6 – male; 7 – Asia Minor newt (Triturus vittatus), female, 8 – male; 9 – axolotl - larva of Ambistoma tigrinum; 10 – Far Eastern toad (Bombina orientalis); 11 – tree frog (Hyla arborea).

Amphibians. 1 – spadefoot ( Pelobates fuscus); 2 – slingshot (Ceratophrys cornuta); 3 – variable atelop (Atelopus varius); 4 – Venezuelan shorthead (Atelopus cruciger); 5 – South African narrowmouth (Breviceps adspersus); 6 – American frog (Rana pipiens); 7 – sharp-faced frog (Rana terrestris), male in breeding plumage, 8 – male in normal plumage; 9 – green frog (Rana esculenta).

Despite the fact that amphibians are distributed throughout the Earth, they are one of the few classes of animals that are practically not used by humans. Unless in the tropics (and in one of European countries, whose inhabitants are called “frogmen” for their passion for frog legs), some species of amphibians are eaten, and biologists also like to conduct experiments on amphibians. Basically, amphibians and humans live on their own and rarely intersect.

Humans' lack of mercantile interest in them does not make amphibians boring. Amphibians have their own characteristics, some of them are very interesting. The selection below includes teeth that do not chew, a frog like a refrigerator, freezing newts, fireproof salamanders and other interesting facts.

1. All amphibians are predators. Even their larvae eat them plant foods only in at a young age, and then switch to live food. Of course, this is not due to some innate bloodthirstiness; it does not exist in nature. Metabolism in the body of amphibians is very sluggish, so they can only survive on high-calorie animal food. Amphibians and cannibalism do not shun.

2. The teeth that some amphibians have are not designed for chewing prey. This is a tool for catching and capturing it. Amphibians swallow their food whole.

3. Absolutely all amphibians are cold-blooded. Therefore, environmental temperature plays a crucial role for their survival.

4. The life of amphibians begins in water, but most of it passes on land. There are amphibians that live exclusively in aquatic environment, but there are no reverse exceptions, there are only species that live only on trees in the humid jungle. So “amphibians” is a surprisingly accurate name.

5. However, even spending most of their time on land, amphibians are forced to constantly return to water. Their skin is permeable to water, and if it is not moistened, the animal will die from dehydration. Amphibians can independently secrete mucus to wet their skin, but the resources of their organisms, of course, are not unlimited.

6. The permeability of the skin, which makes amphibians so vulnerable, helps them breathe normally. They have very weak lungs, so some of the necessary air is drawn into the body through the skin.

7. The number of amphibian species does not even reach 8 thousand (more precisely, there are about 7,700), which is quite a bit for a whole class of living beings. At the same time, amphibians are very sensitive to the environment and do not adapt well to its changes. Therefore, ecologists believe that up to a third of amphibian species are at risk of extinction.

8. Amphibians are the only class of creatures living on land whose offspring in their development go through a special stage - metamorphosis. That is, what emerges from the larva is not a smaller copy of an adult creature, but another organism, which subsequently turns into an adult. For example, tadpoles are frogs in the metamorphosis stage. In the development of more complex organisms there is no stage of metamorphosis.

9. Amphibians come from lobe-finned fish. They reached land approximately 400 million years ago, and 80 million years ago they dominated the entire animal world. Until dinosaurs appeared...

10. The reasons for the appearance of amphibians are still explained purely hypothetically. It is believed that as a result of volcanic activity on Earth, the air temperature increased, which led to intensive grinding of water bodies. Reductions in the food supply for water inhabitants and a drop in oxygen concentrations led to the fact that some aquatic species became extinct, while others managed to escape to land.

11. Amphibians also include caecilians - strange creatures that look like a cross between a worm and a snake. Caecilians live only in the tropics.

12. Dart frogs and leaf frogs are extremely poisonous. Or rather, the mucus that they secrete to wet the skin is poisonous. For South American Indians, one frog is enough to make dozens of arrows poisonous. Lethal dose poison for an adult - 2 milligrams.

13. Common frogs that are found in ponds middle zone Russia, secrete mucus that has a bactericidal effect. A frog in a jar of milk is not an old wives' tale or a way to protect milk from theft. This is an ancient analogue of a refrigerator - frog mucus kills lactic acid bacteria and the milk does not sour longer.

14. Newts, belonging to amphibians, are surprisingly resilient. They regenerate every part of their body, even their eyes. Triton can dry out to the point of a mummy, but if water gets on it, it comes back to life very quickly. In winter, newts easily freeze into ice and then thaw.

15. Salamanders are also amphibians. They prefer warmer ones weather, and at the slightest cold snap they hide under branches, leaves, etc. and wait out the bad weather. Salamanders are poisonous, but their poison is not dangerous to humans - at most it can cause a burning sensation on the skin. However, it is still not worth testing your own susceptibility to salamander venom experimentally.

16. Contrary to popular belief, the fire salamander actually burns in fire. It's just that the layer of mucus on her skin is quite thick. It allows the amphibian to get a few precious seconds to escape from the flames. The appearance of the name was facilitated not only by this fact, but also by the characteristic fiery color of the back of the fire salamander.

17. Most amphibians are very good at navigating familiar terrain. And frogs are even able to return to their native places even from afar.

18. Despite their low place in the hierarchy of animal classes, many amphibians see well, and some even distinguish colors. But such developed animals as dogs see the world in black and white.

19. Amphibians lay their eggs mainly in water, but there are species that hatch eggs on their backs, in their mouths, and even in their stomachs.

20. Individuals of one of the salamander species grow up to 180 cm in length, which makes them the largest amphibians. And the tender meat makes giant salamanders an endangered species, so highly valued is salamander meat in China. Frogs of the Paedophryne species have the smallest size among amphibians, with an average length of about 7.5 mm.