frogs- family tailless amphibians, a contemporary of both man and dinosaur. frog imprinted in itself the longest experience of the struggle for existence in the history of life on land. This led to the universality of her anatomy and physiology, providing a unique adaptation to life in the border zone. Like millions of years ago, a frog begins its life in the water. A tadpole develops from an egg laid in water. So far, it differs little from fish fry. But then a series of transformations begins, consisting of about thirty transitional stages, which helps the frog to adapt to life on land, and the tadpole turns from a "fish" into a land animal (metamorphosis).
Very interesting question: What helps a frog adapt to life on land?
And it helps the frog to adapt to life on land, all those adaptations that appeared during the transformation of the tadpole into a frog. First, the tadpole has its hind legs, and then the front legs. The lungs begin to develop. After a while, it rises to the surface of the water and swallows air, the tail gradually shortens. The tadpole becomes an amphibian, after which it comes ashore. And lives on land, adapting as it should.
From now on, the frog will live on land, more precisely, on the border of land and water. Constant connection with aquatic environment imposes on the biology of frogs whole line characteristic features. The tadpole breathed through gills, but adult frog breathes through the 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 the skin, and when it is on land, it breathes through the mouth and lungs. The circulatory system is also universal. Two parts of the heart work in water, and mixed blood flows through the body. On land, the left atrium is connected to the work, and the blood that is already purely arterial, saturated with oxygen, enters the brain. Thus, with each dive, the frog's respiratory organs are instantly turned off.
While the frog is on the ground It's easy to catch her. And you can't catch it in the water. The hind limbs are long, consist of ten bones - levers. And the forelimbs are a superbly “thought out” device for a “soft landing”. The skin of frogs is naked and covered with mucus, and therefore their activity depends on humidity and air temperature. It hunts at dusk, as the coolness increases. In cold and dry weather, frogs hide in shelters.
When it's winter time, frog sinks to the bottom.
The color of the body is affected not only by temperature, but also by the background color, and illumination, and humidity. Frogs perceive changes in these factors directly with their skin.
One of the most original adaptations to living conditions in the border zone between land and water is frog hearing aid. It turns out that she perceives sound signals through three channels. In the air, sound waves are picked up by the cells of the inner ear, through the eardrum and ear bone. Sounds propagating through the soil are perceived by the bones and muscles of the limbs and transmitted through the bones of the skull to the inner ear.
Frog looks at the world impassively with two large round eyes. They may not be very expressive, but what is unique is undeniable. When studying frog eyes it turned out that the retina analyzes information using special cells. They were called detectors - "detecting". Each type of detector reacts only to strictly defined properties of objects, such as the movement of a stimulus in a certain direction. Each type of stimulus is transmitted along its own optic nerve fiber to a certain layer of the brain. In the brain, the received information is processed, and the animal perceives the object as a whole.
frogs unpretentious and illegible in food, they can starve for a day or a week. They eat butterflies, bees, wasps, and other moving insects. eats fish fry.
For many decades, physiologists have used frogs in a variety of experiments. Observations and experiments with them made it possible to make so many important discoveries that they even erected in Paris and Tokyo frog monuments.
Tree frogs, or tree frogs
A small and very graceful frog; found in Ukraine and the Caucasus, lives on trees and shrubs. She can hold on tightly to the foliage and move along it due to the fact that her fingers are equipped with suction pads at the ends. The color of the tree frog is excellently adapted to the environment in which it lives: it is usually grassy green - the same color as the foliage, but in a different environment, the color can change to brown or grayish. Male tree frogs scream very loudly, inflating the resonator. For spawning, tree frogs descend into water bodies, but remain there for a very short time and soon return to the trees again.
Surinam frog
bright coloring surinamese frog warns predators that an attempt to feast on it will end in death. The Indians of the Amazon Basin smear frog poison, one of the deadliest, on arrowheads. The poison affects the nervous system and causes blood clotting.
goliath frog
They live in waterfalls of fast and full-flowing rivers. They need a lot of moisture, so frogs avoid places with strong sun exposure. Water should be abundantly saturated with oxygen, do not contain tannic acid and be no warmer than 23 degrees and no colder than 16-17 degrees. These giant frogs live in secret most days are spent in the water or among the rocks, which are very difficult to reach. Catching a goliath is extremely difficult, it requires great dexterity and skill. locals catch them with a net with small cells. The net is thrown from afar so that the frog does not see it.
align="justify"> Externally goliath looks like a common frog. Its wrinkled skin on its back is greenish-brown, while its belly and underside of its paws are yellowish and whitish. Eye diameter can reach 3.3 centimeters, the ear is small, without a shell. These frogs do not make any sound. Some researchers evaluate maximum weight of goliaths six kilograms, and the length, if the hind legs are extended, is 60 centimeters. True, these figures are somewhat overestimated, but there is no doubt that the goliath is the largest frog in existence. There is no noticeable difference between male and female, although the latter is slightly larger.
Photo frog Goliath
For a long time, the development of goliaths remained unknown, scientists searched in vain for their tadpoles. But somehow a female in one of the terrariums laid her eggs. They were five to six millimeters in diameter. Now scientists knew what the caviar of these frogs looked like, and began to look for it wherever the goliaths lived. With great difficulty, it was possible to find the caviar, which was attached to the bush of the plant.
female goliath starts laying eggs in the dry season. For 5-6 days, she lays more than 10 thousand eggs. Development from egg to frog lasts approximately 70 days. The tadpole is at first 8 millimeters long, but at the age of 45 days it reaches maximum size- 4.8 centimeters. After that, the tail falls off.
Studies of the stomach contents of goliaths have shown that they feed mainly on insects, but do not disdain crayfish, mollusks, amphibian insects and spiders. Even the remains of small rodents were found in their stomachs.
At first, the main enemies of frogs are birds and, possibly, some fish. Later, goliaths become prey for crocodiles.
The locals of Cameroon and Rio Muni, where these frogs live, consider their meat to be excellent. It is white and tender, and the front paws are a special delicacy...
So far, you can be sure of the safety of these representatives of the animal world. Catching goliaths is very difficult, and they live in places almost inaccessible to humans. But since it concerns a species that can hardly adapt to other conditions of life, everything must be done to preserve goliath frogs.
Frog Goliath - video
The world of amphibians is amazing and diverse. Some evidence for this may be Interesting Facts about frogs creatures, for the most part not causing a surge of positive emotions.
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 wet skin of a frog has bactericidal properties, which is why milk with a frog never turned sour.
Frogs have a very interesting vision - they can look up, forward and sideways at the same time.
Also, the eyes of frogs play an important role in ... digestion. It is with the help of the eyes that the frog helps to 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.
Frogs have a unique respiratory system, because these amphibians breathe both with their lungs and with their mouths and the entire surface of the skin.
While in water, frogs breathe with their skin; on land, their lungs and mouth are responsible for their breathing. The body of frogs is designed in such a way that each time immersed in water, the animal 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 runs in the body.
The hearing of frogs is arranged in such a way that, being on land, they pick up sound vibrations with the help of the inner ear, and sitting on the ground they feel audio vibrations with their skin and bones.
Frogs are the best jumpers in the animal kingdom
Representatives of some species (the frog Litoria nasuta, which lives in Australia) can overcome jump distances 50 times their size and achieve acceleration up to 20 meters per second. Other ( Rhacophorus Nigropalmatus - Wallace's flying frogs living in the humid jungles of Malaysia and Borneo) can not only jump superbly, but even glide, "flying" distances of 15 m.
The size range of these amphibians is quite wide. So, the smallest frog in the world is only 8.5 mm long, and it lives in Cuba.
And here is a close-up photo of the smallest frog.
The giant goliath frog is the largest of its kind.
- its length is 90 cm, and the weight can exceed 3 kilograms. The goliath has very strong legs, thanks to which the average jump of this frog exceeds 3 meters.
Do not think that frogs are harmless creatures. In fact, the frog is the most poisonous land animal in the world.
The breed of this frog is cocos”, she lives only in South America. Cocoa venom is thirty-five times more dangerous than cobra venom.
In Japan, frogs have a very revered role - there they are a symbol of good luck.
And in ancient Egypt, these creatures were also a symbol- but they personified the resurrection, and they were mummified simultaneously with the deceased person. Scientists suggest that this is most likely due to the following. In temperate and cold latitudes, frogs "freeze" every year, falling into hibernation, and come back to life only in the spring.
This is due to the fact that the frog produces glucose. In frost, all liquid with glucose takes on the consistency of syrup, while without the formation of crystals. That is why, after a short winter sleep, the frog is able to survive.
At the moment, scientists have described 5 thousand species of amphibians, and 88% of these five thousand are frogs.
Frogs are amphibians that live in almost all corners of our planet. They can be found in almost any natural environment: in swamps, near other fresh water bodies, on the ground, on trees, and even in a hard layer of clay at a depth of several meters.
Of course, such a different way of life could not but find its expression in the species diversity of these amphibians.
Frogs can be divided into three types: frogs proper, tree frogs, and toads.
The frog is an amphibious great story and ambiguous associations.
Frogs are characterized by slightly bumpy or smooth skin, teeth located on the upper jaw, or swimming membranes on the hind limbs.
The largest frog is. This "overgrowth" can reach up to three kilograms of its own weight, and the length - up to 90 centimeters. The limbs of the goliath frog match its size and their strength too. Thanks to this, she is able to make three-meter jumps.
The smallest frogs live in Cuba, and the length of their bodies in adults is only 12 millimeters, or even 8.5 mm.
But those that do not have teeth. Their skin is covered with pronounced bumps and is also darker and drier than that of frogs. Behind the eyes of toads are well-developed parotid glands. It is also worth noting that although toads are amphibians, unlike frogs, they prefer life on land, being interested in the aquatic environment only during the breeding season.
Toads are predatory amphibians whose way of life is different from that of frogs. The largest toad in the world is, whose weight can exceed two kilograms. In addition, the aga is one of the most poisonous among both toads and frogs. But the smallest toad in the world has a length of only 24 millimeters.
The smallest family among the above are tree frogs. They differ from toads and frogs in that they have extended discs on their fingers that allow them to climb up. Certain types of tree frogs are able to "fly". True, it is difficult to call it a flight in its purest form. Rather, it is not flight, like birds, but planning, like flying squirrels. This ability sometimes renders tree frogs a good service, allowing them to hide from enemies, since they can plan at a distance of up to twelve meters.
The vision of frogs is arranged in such a way that they can look in different directions at the same time: up, sideways and forward. At the same time, they almost never close their eyes for a more or less long period, even during sleep.
Frog skin has bactericidal properties. People have known about this for a long time, and therefore, so that the milk does not turn sour, they threw a frog into it.
True, despite the general harmless reputation, not all frogs correspond to it. For example, in the jungle South America, and especially in the Colombian jungle, there are cocoi frogs, which are recognized as the most poisonous land animals on earth. The poison of such a frog is several thousand times stronger than potassium cyanide and is 35 times stronger than the poison of the Central Asian cobra!
It is worth noting that, being widespread animals, which, moreover, have long attracted the attention of people with their unusual behavior and no less amazing abilities, frogs have left a noticeable mark in world culture.
For example, the Japanese consider frogs a symbol of good luck. But in ancient Egypt, the frog was seen as a symbol of the resurrection from the dead. Sometimes they were even mummified along with the dead. Presumably, this was due to the fact that many species of these amphibians that live in cold and temperate latitudes, with the onset of cold weather, go into hibernation every year, freezing, and then, as it were, resurrecting to life. This ability is explained by the fact that the body of frogs produces a non-freezing molecule - glucose.
Due to this, the fluid contained in the tissues of the frog does not form ice crystals, simply becoming like a syrup, which allows the amphibian to survive.
In European folk culture, the frog is considered an animal that brings rain, symbolizes eroticism, fertility and fertility. Wet skin was perceived by many nations as another symbol of life, in contrast to death, which was associated with dryness.
Among the Celtic peoples, the frog was considered the Lord of the earth and a symbol of healing waters.
Among the Chinese, this is a lunar animal associated with the female power "yin". And the frog sitting in the well was a symbol of a person with limited understanding and horizons.
The Egyptians saw in the green Nile frog not only new life but also abundant offspring, fertility, abundance, longevity and strength that grows out of weakness. She was the protector of newborns and their mothers, and was portrayed as the frog goddess Heket. It was also the emblem of the goddess Isis.
The ancient Greeks, who saw the emblem of Aphrodite in the frogs, did not lag behind the Egyptians. Accordingly, the frog symbolized fertility, sex and harmony between lovers.
The Hindus, as always, gave everything a comic-philosophical character, calling the undifferentiated dark matter, the Great Frog holding the universe.
In many cultures, frogs are mainly represented as a symbol of the waters, resurrection and a harbinger of spring rains.
In Vedic myths, the frog symbolizes the primitive state of homogeneous matter (most likely this was facilitated by the fact that the frog can live almost anywhere, being both in the water and on the ground equally “at home”).
Among Christians, the frog is a symbol of impurity and all the disgust of sin, evil, heretics, envy, greed and insatiable enjoyment of worldly pleasures.
Such different qualities have been attributed to frogs by different cultures, although it must be admitted that, as a rule, they were positive. This is not surprising, because, despite the fact that frogs are more than ordinary animals that live even in the fountains of large cities, they are at the same time an amazing example of survival in a wide variety of conditions, and amazing abilities that have always admired people whose eyes were ready to contemplate and study the nature around us.
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Amphibians (or amphibians) are a class of vertebrates that have 4 limbs and have the ability to live not only on land, but also in water.
Amphibians have their own distinctive features. Their sizes vary from 10 millimeters to 90 centimeters. Therefore, a representative of the class Amphibians can have both a small and a large body. They have 4 bent limbs that are located under the body. They have large bulging eyes. Each representative has long tongue, which is divided in half. The skin is moist, capable of releasing toxic substances. Amphibians breathe with their skin, gills, mouth and lungs. They are ubiquitous except for very hot or cold areas.
The class of Amphibians includes salamanders, spadeworts, tree frogs, toads, and others. The representative of Amphibians is and the frog is a very attractive and interesting species.
Some interesting facts about frogs
- Frogs are representatives of amphibians that are common throughout the planet, with the exception of hot and cold latitudes. In addition, they can live both on land, at a height of several meters, and in water, at great depths.
- Frogs have smooth skin that can release toxic substances. Toxins secreted by the skin are needed by frogs for defense and for attacking prey. To signal that the frog is poisonous, a bright skin color can. Some frogs, which are not capable of excreting toxic substances, may also have a brightly colored skin, thereby protecting themselves.
- Frogs are predators. They feed mainly on insects (wasps, flies, mosquitoes). A species such as the lake frog feeds on fry.
- Frogs have a pair of teeth that are located in the upper jaw. With their help, she holds food before swallowing. A captures food with the help of a forked tongue.
- The largest representative of the frogs is the goliath frog, whose length is 82 centimeters. She has a strong physique. The jump of the goliath reaches 3 meters.
- Kokoi is the most poisonous frog, having a greater degree of toxicity than that of a cobra.
- With the help of frogs, you can determine the pregnancy of a woman. To do this, the urine of a woman is injected into the frog. And if after a while the frog lays eggs, then the result is positive.
- In some species of frogs, the offspring reaches a larger size than the female herself. While the female is 6 centimeters long, her offspring are 25 centimeters long.
- Not all frogs have the ability to "croak". The goliath frog is mute, and some species are able to sing. Certain types of frogs are able not only to sing, but also to grumble, ring, grunt.
- The frog is a symbol of good luck used in Japan. And in ancient Egypt, frogs were used as a symbol of resurrection.
- The skin of the frog has bactericidal properties. That is why in ancient times, when people did not have refrigerators, the frog was thrown into a jug of milk, thereby preventing it from sour.
- Frogs have special vision. The peculiarity lies in the fact that the frog can simultaneously look both up and sideways and down.
- During sleep, frogs practically do not close their eyes. When closed, they keep them for only a short period of time.
- During the growth of a frog, the tadpole has 30 stages of transformation.
- Frogs drink water with their skin without touching their mouth.
- Hot weather, especially the scorching sun, is extremely dangerous for frogs. At a temperature of 30 degrees, the frog dies. This is due to the fact that the frog is a moisture-loving animal that constantly requires water. It is because of the lack of moisture that the frog dies.
- During the breeding season, frogs are in the water, and then migrate to land. Frogs breed in the spring, during the rains. It is at this time that very talkative male frogs take their places on the bumps and croak loudly.
- In France and South Asia, frogs are used as food. Frogs make up 1/3 of the total food of the population.
- In nature, frogs are used as exterminators of a mass species of pests.
- Frogs, unlike other species of the class Amphibians, do not have a neck, but have the ability to tilt their heads.
- Many believe that frogs are somehow connected with the other world, which is why it is undesirable to kill frogs.
- During growth, the frog has a tail, and as an adult, it discards it.
- Surprisingly, the frog has a brain! Also nerves and spinal cord. But the nervous system of frogs is poorly developed.
- The glands of the tree frog secrete hallucinogens that can cause loss of consciousness, memory impairment, and hallucinations.
- The lifespan of a clawed frog is 33 years! But our frogs live for 17 years
- Frogs have a 3rd eye, specifically the 3rd. It is barely noticeable, resembles a wart and is located between the two main ones.
- Frogs use their eyes to push food down the esophagus. They do not have the ability to perform such actions with their tongue, so frogs use their eyes by tensing certain muscles. That is why frogs often blink while eating.
- But not all frogs spawn in water. Such a species as snub-nosed ones are able to carry their offspring in the stomach, and hairy ones in the mouth.
- Panamanian golden frogs perceive sounds not with their ears, but with their lungs.
- The African frog has the ability to protrude its claws on its limbs through the skin and then retract. This is how frogs defend themselves.
- Frogs have nostrils. It is through them that they breathe. But besides the nostrils, the frog can breathe through the skin.
- Frogs are capable of jumping long distances. Representatives of frogs, not exceeding 10 millimeters, are capable of jumping up to 60 centimeters. And certain types up to 3 meters!
Interesting video about the biggest frog.
Frogs, in the narrow sense, are called only representatives of the family of real 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.
Tailless move around in a variety of ways. Depending on their habitat, they jump, run, walk, swim, burrow, climb trees, or glide.
Anurans are considered the best jumpers of all vertebrates (in terms of the length of the jump relative to body size). The Australian frog Litoria nasuta can jump more than 50 times its body length (5.5 cm). Jump acceleration can reach 20 m/s 2 .
The frog starts its life in the water. From the eggs laid in the water, a tadpole develops, similar to a fish fry. A series of transformations, consisting of about thirty transitional stages, helps the frog to adapt to life on land, and the tadpole turns from a "fish" into a land animal.
The tadpole breathed through 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 the skin, and when it is on land, it breathes through the mouth and lungs. The circulatory system is also universal. Two parts of the heart work in water, and mixed blood flows through the body. On land, the left atrium is connected to the work, and the blood that is already purely arterial, saturated with oxygen, enters the brain. Thus, with each dive, the frog's respiratory organs are instantly turned off.
The skin of frogs is naked and covered with mucus, and therefore their activity depends on humidity and air temperature. It hunts at dusk, as the coolness increases. In cold and dry weather, frogs hide in shelters.
The color of the body is affected not only by temperature, but also by the background color, and illumination, and humidity. Frogs perceive changes in these factors directly with 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 boundary zone between land and water is the hearing aid of the frog. It turns out that she perceives sound signals through three channels. In the air, sound waves are picked up by the cells of the inner ear, through the eardrum and ear bone. Sounds propagating through the soil are perceived by the bones and muscles of the limbs and transmitted through the bones of the skull to the inner ear.
Frogs are unpretentious and illegible in food, they can starve for a day or a week. They eat butterflies, bees, wasps and other moving insects. The lake frog devours fry of fishes.
Once a frog grabs an unsuspecting insect, it must blink: the eyelids push the eyeballs up to the top of the mouth and actually help push the food down the throat. By the way, the eyes of frogs are larger than the stomach.
Most frogs have teeth in their upper jaws, but these are mainly used to lock prey in their mouths and prevent them from escaping before the eyeballs push them 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 supposed) 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 quite recently in Tokyo by medical students. For their experiments, they used 100,000 frogs, in honor of which 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 jump three meters long.
The bullfrog, or bullfrog, is one of the largest tailless amphibians. In length, it reaches 20.3 centimeters and weighs up to one and a half kilograms. This frog is one of the most common laboratory animals in the world. North America. So, only in 1973, more than 10,000 individuals of this species were destroyed in the universities of California for educational and scientific purposes. But they also eat these animals actively. Catching in various ways (fishing rods, nets, nets, traps) or killing with a gun, these frogs have been hunted for the festive table since ancient times. Until now, about a hundred million bullfrogs are harvested in the United States annually. However, to catch them, you must have a license and conduct it within the terms strictly defined by law and by permitted methods. In the last decades of the last century, even frog farms were created. The commercial weight of the frog "goby" reaches only 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 well tamed. So, 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. For bullfrogs, the phenomenon of homing is still characteristic (from the English homing - a sense of home) - the ability to return to the place of capture after release at some distance from it.
The smallest frogs living in Cuba have a body length of 8.5 mm to 12 mm.
The vision of frogs is arranged in such a way that they can look forward, sideways and up at the same time. They never close their eyes for a long time, even during sleep.
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 that 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 than 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 living in temperate and cold latitudes annually hibernate, freezing, and resurrect again in the spring. The fact is that frogs produce an unfreezing molecule - glucose. The liquid in the tissues becomes syrupy from frost, without forming ice crystals, which allows amphibians to survive.
The first to come down to us piece of art, in the title of which the tailless appear - this is Aristophanes' comedy "The Frogs", first staged in 405 BC. e.
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